Transcript: Surge Alert: Understanding Covid Surges and Variants

Jessie: Hello, and welcome back to episode 11 of the COVID Longhaulers podcast. We share real stories from those living with long COVID, what they faced, how they're coping, and surviving. Today, instead of sharing a Longhaulers story, we'd like to give you all you need to know about surges and variants.

Since some of the discussion around these topics can be confusing and complex, we'll break it all down for you, so you can be informed and make better decisions about how best to protect yourself.

My name is Jessie, and I'm co-hosting today with Emerson.

Emerson: Yeah, and right before we dive in, I would quickly like to mention a couple disclaimers. We have done our best to gather information from credible and reputable sources, but this podcast isn't medical advice. We're not doctors or scientists. We're really just a bunch of data nerds who love digging into numbers and making sense of trends, and we want to help break down this complex data into something that is a bit more understandable and accessible to everyone.

And you might also notice that a lot of our research that we will talk about is focused on the US, and this is not because we don't care about the rest of the world. I myself am from Switzerland, but sadly, there is just far more data available from the US than most other parts of the world.

Jessie: Right, we've done our best, but it was difficult to find in some places. You can find all of our research, as well as a glossary with the COVID-related terminology that we use in the substack posts linked in our show notes.

Now that we've gotten all of that out of the way, I think we can get started. So, since the start of the COVID pandemic five years ago, we have all lived through a bunch of COVID surges, as well as the predictable triple-demics and quad-demics, where flu, RSV, norovirus surged at the same time as COVID in the fall and winter. We've all heard and likely used the word surge before, but what exactly does it mean? What is a surge?

Emerson: [00:01:59] When a significant amount of COVID infections occur in a region at the same time, we call it a surge. So, surges happen at different times and different parts of the world due to a number of factors based on things like human behavior – so for example, when you spend more time inside with others, also things like vaccination availability in other mitigations such as masking in public or viral mutations also play a role in when and how surges happen.

When there's a surge, a lot of people get sick at the same time, but most of them recover and develop short-term immunity to that specific virus. And then after the surge, the infection rates usually drop for a while due to the immunity that you get after an infection, but within four to six months that immunity starts to wear off. And to make things trickier, the virus itself evolves in that time. So there are new variants of that virus circling around and these new variants can sneak past our fading immunity, leading to another round of infections, so another surge. And that leads to the wave-like COVID patterns that we currently see. How often do these surges happen, Jessie?

Jessie: It looks like COVID now surges about twice a year in most countries of the northern hemisphere, but it varies by country and region. The U.S. and Europe see the most pronounced winter and summer surges due to their temperate weather. The southern hemisphere also shows similar, dual surges in their winter and summer. In tropical areas, the surge pattern is more fragmented and noisy without clear seasonality.

One study found that variants in the tropics followed three to seven overlapping ‘wave-like accumulation patterns’ because temperature and humidity fluctuations that influence people to congregate indoors are less present. Interestingly, the UK also has multiple- about three to four- COVID surges every year. Their strongest surge is between November and January with a notable rise in hospitalizations and winter quad-demic events.

Emerson: And why exactly do surges happen this way?

Jessie: Most folks are aware of respiratory illness peaking in fall and winter but overlook summer, although the drivers of the surge are mostly the same in both seasons. Sharing unfiltered indoor air seems to be the biggest determinant. When it gets hot, people congregate inside in air conditioning, they shut the windows. In places where air conditioning isn't as common, cultural norms in the summer still aid transmission as people are off from work or school and find lots of reasons to congregate. People travel more in summer, helping the virus find more hosts that take it back to their homes and spread it there.

Emerson: Yeah, and these human behaviors lead to the increased transmission of COVID because it is an airborne virus. That means that when an infected person exhales, they can release particles and droplets of respiratory fluids that contain the COVID virus, SARS-CoV-2, into the air. And these droplets carry the virus and transmit the infection. So once those infectious droplets and particles are exhaled, they move outward from the person and if indoors, the very fine droplets and particles will continue to spread through the air in the room or the space that you are in and can continue to accumulate if there is no ventilation. So people get infected by breathing in these particles even from across the room or after the infected person has left because the virus can stay in the air for hours.

Jessie: Yeah, and this brings us to the hot topic of super spreader events. So what are super spreader events?

Emerson: Super spreader events don't really have a very clear-cut definition, but in general a super spreader event occurs when a big group of people congregate without taking any kinds of precautions. So those are things like weddings, funerals, birthday parties, and holiday gatherings. Those are all common occasions where the virus can spread quickly if precautions aren't taken.

And we see this very commonly in winter where COVID surges after the holiday season because families get together and spend lots of time with each other. The larger the crowd is, the higher the risk of infection is, particularly if someone attends while feeling unwell or after a recent exposure to the virus.

Jessie: And it's important to know that any large social event in your life can become a super spreader event with the right conditions. Social norms, lack of planning, and FOMO, the fear of missing out, make it difficult for people to cancel a trip or sit out of an event if they have symptoms, or cancel a wedding that's been planned for years. So the event goes on full speed ahead. I myself got my one and only COVID infection from a funeral where someone showed up sick and, at that time, we were only using cloth masks to protect ourselves.

Besides the typical family gatherings or outings with friends, larger public events are known to be some of the biggest super spreader events. Professor Christina Pagel from University College London explained,

“We know the most dangerous places for COVID-19 transmission are indoor, crowded, and poorly ventilated. Singing or shouting makes things worse since more virus is released with every breath.”

Emerson: Yeah, that means that an arena, even if it's an open arena, would be a great place for COVID to spread. And that means that festivals, concerts, parades, all that kind of stuff that we love to do in the summer can be a massive super spreader event.

And we have seen this in the past. One of the most recent events that I can think of is Taylor Swift's “Eras Tour”, where a lot of fans came together and then afterwards a lot of them ended up posting on social media how they had gotten COVID at the concert and were telling other people, “hey, take a COVID test if you're feeling unwell". And another less recent example is when two festivals in Japan accelerated COVID spread and caused two massive peaks in the summer of 2022 – simply because so many people came together and shared air with each other. So super spreader events are definitely dangerous and risky.

But Jessie, why don't we see the flu or other viruses peak in the summer?

Jessie: That is an interesting question. Turns out, and I'm going to read this quote:

“the number of COVID cases that are present year round is so much higher than we see for flu or RSV”.

That's Andy Pekosz, a professor of molecular microbiology and immunology at Johns Hopkins. Because of this higher baseline, there are more cases to fuel a larger wave of infections. So when conditions are right for transmission, like increased travel, increased indoor gatherings, transmission explodes. He goes on to say, with flu or RSV, there are so few baseline cases during the summer that these changes in behavior don't cause the same spread.

And that's really interesting because in the US last summer, symptomatic people were claiming that they had “a summer flu and not COVID”, despite there being virtually no flu circulating according to public health surveillance data. And this was likely exacerbated by the ineffectiveness of the rapid COVID tests, the lack of public health messaging, and unfortunately, the cultural push to not rest or reduce transmission to others when you're ill.

Emerson: It's a massive issue that people don't even know that they have COVID anymore and then just go ahead and spread it around.

So how do we know when a surge is coming or if we are already in one?

Jessie: Well, at the beginning of the pandemic, at least in the United States, an estimate of the amount of COVID circulating from healthcare practitioners, hospitalizations, and labs was reported regularly to local public health departments who would then report to the CDC. Then the CDC would provide this data to the public and use it to inform guidance on mitigations.

Emerson: Yeah, we had a very similar system here in Switzerland and Germany, and I think other parts of Central Europe managed it very similarly to the US.

Jessie: As the US changed their posture on COVID protections and ended the public health emergency designation, this no longer happens and we rely solely on wastewater surveillance data, which unfortunately is not uniformly available everywhere.

Emerson: [00:10:49] So wastewater data is really the only data we have on how much COVID is currently being spread and that can help us identify outbreaks and see where they started and how they're spreading. So wastewater data works by taking samples at wastewater treatment plants multiple times a day or a week and then those are sent to a lab to detect genetic material from pathogens using PCR tests. For decades, scientists have used wastewater to track things like polio outbreaks throughout the world. It had never really been used to track respiratory diseases until COVID and now we use it to track things like flu, monkeypox, and RSV as well.

And the benefit of wastewater surveillance is that it doesn't really rely on people to be tested because so many healthcare facilities in many places unfortunately no longer test for COVID for a variety of reasons. So, wastewater is the only evidence-based way to see how much virus is actually circulating in the population. And another benefit of wastewater surveillance is that we can see which variants or strains are circulating with better accuracy than with individual tests.

Wastewater data works because people with COVID can shed the virus in their waste for days or even weeks before they show any symptoms – because incubation periods can be pretty long and/or people can stay asymptomatic completely. And this can provide an early warning system in wastewater surveillance.

Jessie: However, some strains of COVID have been shown to differ in the amount of virus shed, which can make estimates of how much is actually circulating a bit trickier.

Emerson: For any of our listeners who want to keep track of COVID through wastewater surveillance, you can find a list of wastewater surveillance dashboards by country – at least those that we were able to find – in the substack post that is linked in our show notes. And if we are missing a wastewater surveillance dashboard from your country, then please send us an email so that we can add it to our show notes.

Jessie: We used to be able to tell a surge is coming by an increase in hospitalizations with a certain variant. The World Health Organization member states voluntarily report hospitalizations which can be seen on the WHO COVID dashboard. However, the quality and completeness of that data is in question, given that, number one, a fraction of the member states are reporting to WHO these days as compared to the early days of the pandemic. It was noted in 2023 that less than 20 countries were still reporting hospitalization data. And number two, in some reporting countries, testing for COVID is no longer commonplace in symptomatic people, so hospitalization data isn't representative.

In the United States, reporting COVID hospitalizations is voluntary, which makes it exceptionally difficult to assess spread. But you can at least see what is reported on the CDC dashboard, which we will link in our substack post for this episode.

Emerson: So basically in summary, wastewater surveillance is the best tool that we have in assessing what strains are circulating and how much is currently circulating.

Jessie: [00:14:03] Now that we've covered the ins and outs of surges, let's talk about the impacts of how we deal with these surges. When world leaders say, “COVID is here to stay”, it's clear that what they mean is that we all must accept everything about COVID surges – that is, deaths, long-term damage, and frequent illness as normal, that this is the new baseline for society. That means that our governments have no plan to halt these surges or to minimize the damage by mandating masks, especially in healthcare facilities during these periods. Instead, COVID can just run free to mutate, infect, disable, and kill people while the damage that COVID causes is minimized.

Emerson: And we see that in how new variants are described. They are often described with descriptions like “they are not worse than other variants”. So the focus is on the virus not being worse rather than what damage this and previous variants have already caused or could potentially cause. And that means short and long-term damage – so the risk of death from acute infections, but also the risk of developing long COVID or the link of COVID to cancer, all these kinds of things.

And essentially, we as a society have accepted that the level of death and disability that every variant causes is normal – which is completely crazy to think about because I couldn't imagine us doing that about other things. So Jessie, what is the level of death estimated that we have accepted?

Jessie: In the summer surge of 2024, for example, the CDC data reported that over 1,000 Americans a week died of COVID. That's last year. A thousand Americans a week died, and the number is likely much higher.

In Europe, the UK experienced around 150 weekly COVID deaths in the summer surge of 2024. In Germany, a total of 183,000-ish people died of COVID in 2024. And it was really hard to find these numbers because COVID deaths are barely being covered anymore.

Due to the lack of available real-life data, we have to base more exact COVID deaths on estimates.

Emerson: Yeah, and that's why I'm really thankful that we have an estimate from the Swiss Re, which is an insurance company that insures other insurance companies. And they wrote a report on how excess death has changed since the start of the pandemic.

You can find both the links to the report and also the video by Dr. Michael Hoerger in our show notes to find out more about the math behind this because it is pretty complex to explain all of it here. But the report estimates that in the US, around 1.3% to 6% of all excess deaths in 2025 are caused by COVID. These deaths are deaths that wouldn't have happened if COVID as a virus wouldn't exist. It is important to note that the 6% figure is considered to be far more realistic as the 1.3% is likely too optimistic as it doesn't account for major long-term damage that an infection can cause. These rates are broadly transferable to other countries, but there are some regional differences based on things like access to health care, economic stability, all these kinds of things.

And based on this, Dr. Hoerger projects that in 2025, 109,000 to 175,000 COVID related deaths will happen. That is about 2,100 to 3,400 COVID related deaths per week, or one death every three minutes. Let that sink in.

It is important to mention though that most of these deaths are not being counted as COVID deaths. They are being listed as things like heart disease, dementia, or cancer, even though COVID is the underlying cause of these diseases. For comparison, in April 2025, the CDC officially reported around 350 COVID deaths per week or one death every 30 minutes. And that huge gap shows us just how much COVID mortality is being undercounted and how much this disease is being minimized.

So I want to put all of this into perspective. COVID's projected death toll is on par with, or even higher than, lung cancer, which causes about 125,000 deaths a year. And yet we would never say things like, “oh, we're in a post-lung cancer society”. We would never say that. We recognize that lung cancer is serious, that it is an ongoing health issue, and we treat it as such. For example, public health campaigns warn us about smoking because of its link to lung cancer, but with COVID, the risks are downplayed. Most people still aren't being informed about the dangers of a COVID infection and how high the risk of disability is.

Jessie: And these are only death rates – this does not include the amount of disability caused by infection or acknowledgement of the personal and economic cost of acute illness that lasts for weeks. Multiple studies show risk anywhere from 5% to 20% of people getting long COVID from their first infection.

Emerson: And we know that a total of 10 to 40% of people who have had COVID at some point in their life went on to develop lung COVID.

Jessie: We also know that each infection after that carries a greater risk of disability. The Center for Infectious Disease Research and Policy, or CIDRAP, reported that those with two COVID infections were 2.14 times more likely to report long COVID than just one infection. And those with three or more infections were 3.75 times more likely.

It's worth noting that long COVID is absolutely not rare, despite the cultural messaging circulating. In medicine, a condition with 0.1% prevalence is considered rare. We're talking about something that, at the very least, is 60 to 200 times more likely than that percentage, only on the first infection. Then double and triple the percentage with a second or third infection.

The Pandemic Mitigation Collaborative Dashboard is a great resource for understanding just how prevalent COVID is in the population at a given time. Last year in August, their numbers estimated that 1 in 36 people in the United States had an active COVID infection, which is about 2.8% of the population. Based on this, they estimated that just in one week in August, about 9 million people were infected, resulting in a range of 468,000 to 1,870 ,000 people getting long COVID. That's in one week.

Can you imagine anything else that would disable that many people in a week? We have accepted as a society that millions more every year will have long-term health consequences as well as near-term disability.

Emerson: Right, and besides long COVID, this virus can cause other long-term damage in our bodies. It weakens our immune system, it causes cardiovascular and neurological damage, and it has even been linked to cancers. And it is still being downplayed, even though no part of your body, no system in your body, goes unharmed after a COVID infection. If you want to find out more about this, I recommend you check out our eighth episode called The Invisible Damage of COVID-19.

Jessie: In the summer of 2024, the public health messaging was at that time and continues to be insufficient at controlling disease and its consequences. The only precaution recommended by public health officials, despite millions getting newly sick each week, many who already had several COVID infections under their belt, was vaccination – which we know does not stop transmission, but only lessens the severity of COVID. And the recommendation is to get vaccinated yearly despite that protection wanes after just a few months. Since many people get vaccinated in the fall when the new vaccines come out, most of the protection they offer has reduced significantly by the summertime.

The best way to reduce mortality and disability from a disease is not to get it in the first place. “An ounce of prevention is worth a pound of cure”, as we say in the US. Yet, it's been years since the CDC recommended any mask wearing during surges. Additionally, the CDC's quarantine guidance continues to not be based on empirical data to reduce transmission and has caused confusion among American workers. Many employers require workers to come to work sick with COVID and won't let them wear a mask because they might scare customers or etc.

Emerson: So, given the lack of protection and control measures, the inadequate public health policies and how low vaccination rates are, and also the waning protection from vaccination – we are likely to continue to see this mass death and disability every year multiple times each year.

[00:24:00] By now, you've likely heard about variants, the new ones that are on the scene, or perhaps you've heard about how some variants are less deadly or more contagious. So let's break down what a variant is and why it matters.

Jessie: When a virus infects a group of hosts – in our case people, but also animals such as the rats in the New York City sewers, and I'm not talking about the Teenage Mutant Ninja Turtles🐢 – these viruses make copies of themselves. Just like if you did something over and over again, like for example, writing your own name on a piece of paper – you're bound to have some variation in how you create the letters. Similarly, as the virus copies itself, it can randomly change, and this change is called a mutation. Some mutations do nothing different that we can observe while others may help a virus get better at infecting hosts, avoiding the immune system, or withstand treatment. If a mutation changes how a virus acts in a group of people, it's called a variant or a strain.

Emerson: And SARS-CoV-2 is tracked by scientists throughout the world to monitor variants. Genetic surveillance identifies SARS-CoV-2 variants that have the potential to be more transmissible or better at evading our immune system or even cause more severe acute disease, for example, have higher mortality rates. It is important to mention that at this point, the severity of long-term damage that this variant could cause is not taken into account. The focus is solely on the acute infection and what that mortality rate could be. So these new variants are classified as ‘variants of interest’ or ‘variants of concern.’

Jessie: Yeah, so what is a ‘variant of interest’ or a ‘variant of concern’, Emerson?

Emerson: A ‘variant of interest’ is a variant that shows genetic changes that may affect the virus's behavior. So things like how quickly it spreads, how immune-evasive it is, etc. And just a reminder, by immune-evasive, we mean the ability of a pathogen to escape detection or elimination by the immune system. So basically, it can hide out in our body without our immune system reacting to it.

And a ‘variant of concern’ is a variant that has very clear evidence of increased transmissibility, severity, or a reduced effectiveness of public health measures. It is a variant that poses a significant global health threat.

Jessie: The World Health Organization has designated five variants of concern with Greek letter names to date: Alpha, Beta, Delta, Gamma, and Omicron.

This is different from other naming conventions that use binomial nomenclature, like plants, animals, bacteria – all use binomial nomenclature. Which is basically genus, then species. So an example of this binomial nomenclature that you're already aware of is the Tyrannosaurus Rex. Tyrannosaurus is the genus name, and Rex is the individual species within that genus. So, there are other dinosaurs besides the T-Rex that are Tyrannosaurus.

Emerson: But this common standard for naming isn't used for viruses in this case?

Jessie: Correct, it is not. In fact, there isn't really a standardized way to name them. And there are so many variants floating around that don't have that Greek alphabet letter naming such as this latest variant, NB.1.8.1. So, if you're confused by letters with dots, with numbers like JN.1, it's written JN.1, BN.1.1.7, etc. – you're not alone. It's actually a system based on the lineage and evolution of the variant. It's too tedious to explain verbally, but you'll find a link to a list in our sub-stack write-up if you really want to nerd out.

Emerson: There are some noteworthy things to know about the five lineages that have been designated as variants of concern by the World Health Organization, so Alpha, Beta, etc. The Delta variant in 2021 caused more than twice as many infections as the previous variants. And one study found that people were twice as likely to be hospitalized with Delta than with Alpha.

Jessie: You've likely also heard of the spike protein, which is how the virus attaches to our cells and infects us, especially if you've listened to our episode on the invisible damage of COVID. Well, Omicron was a dramatic shift in the virus's evolution, with double the number of mutations in the spike protein. Because of this and its stronger ability to transmit between people and evade prior immunity, the World Health Organization named Omicron as a ‘variant of concern’. When it came on the scene in November of 2021 – within four weeks, the Omicron wave traveled around the world and replaced Delta as the dominant variant, which is an astounding speed.

Emerson: As of now, Omicron is the only lineage infecting people. A lineage is a collection of variants with the same ancestor, so all the current variants circulating are all basically children and grandchildren and great-grandchildren of Omicron, but we'll get back to that in a second. Alpha, Beta, Gamma, and Delta are all now classified as previously circulating ‘variants of concern’.

Jessie: How is it that the Omicron variant mutated so fast and differently from other lineages?

Emerson: There isn't a really clear answer to this. There are a couple different theories on this, and they all come down to Omicron's origins.

The most popular theory is that Omicron may have emerged in a population with prolonged viral replication, possibly in an immune-compromised individual – so for example someone with HIV. This could have allowed the virus to gradually accumulate a significant number of mutations over a considerable length of time, and that kind of led to the distinct genetic makeup that we can observe in Omicron and its descendants.

Another hypothesis for why Omicron has so many mutations is that it went from humans to mice, mutated a lot in mice, and then went back to humans. This is why scientists have been concerned about other animals being infected because it can accelerate mutation. This is also why bird flu is such a hot topic – or at least it was last year or so, because there's a lot of opportunity for that virus to mutate again and again and again until it hits the right combination of concern for human-to-human transmission.

Jessie: Since Omicron first appeared, it has given rise to several subvariants, like its children, BA.2, BA.5, and its grandchildren, XBB and BQ.1. While these have genetic differences, they remain similar enough to be classified under the Omicron umbrella rather than as entirely new variants. Scientists refer to this ongoing evolution as “Endless Omicron.” Its continued dominance is largely due to its high transmissibility and its ability to evade immunity from both vaccination and prior infections – making it hard for other variants to take over. Every time a new variant comes on the scene that appears to out-compete previous variants, it's important to ask three questions. What are those three questions, Emerson?

Emerson: Number one, is it causing more severe disease?

Number two, is it more contagious?

And number three, do existing vaccines still work against it?

Jessie: Yeah, and as long haulers, we of course wish that many more questions were asked about the variants' effect on vulnerable people – any noteworthy worsening of long-term effects on body systems, the likelihood of developing Long COVID, etc. The main focus of the World Health Organization and other authoritative bodies is always on acute infections from a variant, rather than the fallout of said infections.

Emerson: Yeah, so that's an explanation of variants in a nutshell, but I just mentioned subvariants. Jessie, can you explain what those are?

Jessie: So, some variants are actually subvariants. A subvariant is basically just a child or descendant of a previous variant. Since the virus keeps mutating, especially when it's spreading to so many hosts constantly – remember what we said earlier about writing your name down over and over and over again and how there will be variation? Well, some of those new copies are going to change just slightly, and those slight changes are now a subvariant of the original variant.

Emerson: The next ‘variant of concern’ will be named Pi. For Pi to be designated, there would need to be a large difference in the genetic sequence compared to the Omicron lineages, and the variant would have to be significantly more infectious or cause more severe disease than what we are currently seeing.

Jessie: So, why do new variants turn into surges?

Emerson: Well, variants are kind of like entirely new diseases. They can be more transmissible than previous variants or better at evading the immune system. And vaccinations have a much shorter window of protection than what we previously thought. Most of us have likely been told that the immunity of a vaccine will last for about six months, but this is really not the case. Vaccine protection against symptomatic Omicron – so you can still get Omicron asymptomatically, mildly – It doesn't completely immunize you against COVID – so the vaccine protection at the beginning is around 65 to 75% after a full two-dose series or a booster dose, so you never have full immunity. This protection declines sharply over time, dropping to about 10 to 15% within five to six months.

Jessie: Yeah, and in the US and Europe, vaccines are available typically yearly starting in the fall, but the vaccine only provides protection for up to six months, leaving many vulnerable to severe disease, given that there are at least two surges a year now. The population no longer is attempting to avoid transmission, meaning more mutations in a shorter time, making the vaccine less effective at targeting the virus.

Emerson: Do we know if some variants are worse for long haulers than others?

Jessie: Well, studies show that to date, long COVID prevalence is similar across all variants. Where evidence of less prevalence existed, it was mostly attributed to populations being vaccinated, which decreases the likelihood of serious disease, which is a risk factor leading to long COVID. The vaccine is generally considered to be a protective factor for long COVID, reducing the risk by up to 50%.

Emerson: So what do we know about the current surge that is happening right now? What's happening globally?

Jessie: According to the World Health Organization, global COVID activity has been climbing steadily since mid-February this year. As of mid-May, test positivity was sitting at about 11% across 73 countries. To give you some context, that's the same level we saw during the July 2024 peak. This marks a significant rise as back in February, the number was just 2%.

Emerson: The surge seems to be growing at different speeds around the world. For example, the increase in test positivity was mainly taking place, back in May, in countries in the Eastern Mediterranean region, in the Southeast Asia region, and the Western Pacific region. That means that in some countries, specifically parts of Asia, the peak has already passed.

For example, Hong Kong, Singapore, China, and Thailand have already experienced a sharp increase of COVID cases around May this year, and they already seem to be back on the mend. So the surge is already mostly over. On the other hand, the surge is only just starting to grow in Europe and North America.

Jessie: The COVID-19 Scenario Modeling Hub as of June 4th, forecast two peaks this year in the United States: A summer peak around late August 2025, a second winter peak in January 2026. Both peaks are expected to reach similar levels as last winter, around 20,000 weekly hospitalizations.

This is likely a very conservative estimate given that at the time of this recording, access to COVID vaccines in the United States this year for people under 65 is very much at risk due to political appointees overruling expert opinions at the FDA.

And it will likely look pretty similar in terms of cases across most of Europe as well.

Emerson: So according to the pandemic mitigation collaborative current COVID cases in the US, are rising at the moment- around one in 148 people is currently infectious with an average of 324,000 new daily infections. Dr. Hoerger from this collaborative forecasts that it will continue to rise with one in 80 people being actively infectious and an average of 590,000-ish new daily infections by next month.

And I'm honestly pretty jealous that you guys in the US have so many cool and smart people who create these COVID forecasts. You can of course find these in the list of COVID dashboards that we created. But over here in Switzerland, and I think I can speak for most of Europe and maybe the entirety of Europe, we don't have these kinds of collaboratives or scientists who forecast COVID cases. So our information on cases is often less accurate, but we do still have some information. As of June 29th, according to Our World in Data, cases have been climbing steadily across Europe. For example, Norway is currently experiencing about 61,000 confirmed COVID cases per million people – Greece has about 109,000, Lithuania 53,000 and the UK nearly 20,000 cases per million people.

Jessie: But you need to keep in mind that the rates that Emerson just mentioned only represent the number of laboratory confirmed COVID-19 infections as reported to the World Health Organization. So they don't capture the true scale of infection due to varying testing strategies, case definitions and under-reporting. COVID cases are probably far higher in most countries.

And to make things even trickier besides the lack of COVID testing and reporting, this year it seems that we can't really fully rely on wastewater data either. We recently came across two studies that pointed out that due to specific mutations in newer Omicron variants, wastewater data is undercounting these variants, leading to skewed data, making the COVID rates seem lower than they actually are.

Emerson: Yeah, so basically wastewater testing in most places around the globe rely on testing a region of the SARS-CoV-2 genome that has actually changed. The testing is done the same way as it was with the original Omicron variant, however newer and the current variants are genetically very different to the original Omicron. And this has resulted in a major under-sensitivity of most wastewater testing of COVID.

So according to this data, wastewater has been unreliable for at least two years and it has been getting worse with time, meaning that this summer COVID is likely being undercounted by 25 to 50%.

Jessie: Right, and that would explain why we've not seen wastewater rise the way we would expect it to. COVID is circulating at far higher rates than is being communicated by authoritative sources or wastewater surveillance. I think we've all observed a gap between the reported COVID cases, be it test reports or wastewater data, and the COVID we've observed spread through our communities and cities. But what's even scarier is that half of the COVID cases this summer are asymptomatic, meaning that the massive amount of illness we can see spread is only half of what is actually circulating.

And because we know that COVID historically always peaks around the same times of year, we can expect that this year will be no exception, even if we have no real-life data to back it up.

Emerson: This summer surge is being driven by three major variants, LP.8.1, XFG, also known as Stratus, and NB.1.8.1, which has been nicknamed Nimbus and is generally also known as Razor Blade Throat due to the symptoms it causes.

All three of these variants are designated ‘variants under monitoring’ by the World Health Organization. But what exactly is a ‘variant under monitoring?’

Jessie: This is the World Health Organization's initial alert level for new variants. A ‘variant under monitoring’ is a SARS-CoV-2 strain that shows genetic changes suspected to affect virus characteristics like transmissibility, disease severity, or immune escape, as mentioned before. But without significant evidence yet of significant public health impact. The World Health Organization and national agencies continue to study these variants closely through genomic surveillance, lab tests, and epidemiological data. If clear impact is observed, a ‘variant under monitoring’ may be escalated to a ‘variant of interest’ or ‘variant of concern.’

Emerson: Right, and there are regional differences as to where these variants are the most active. They are the driving forces of the surge in different areas of the world. In New South Wales, Australia, LP.8.1 made up around one in five COVID cases, and in the UK it was responsible for at least three of five COVID cases.

On the other hand, XFG is gaining ground. It currently makes up 20 to 30% of sequenced SARS-CoV-2 samples in many regions. However, there is no concrete real-time infection number at the moment because of the lack of continuous sequencing and coverage. In the US, XFG made up around 14% of the cases as of June 21st this year, and in the UK, XFG accounts for about 30% of the sequenced cases.

Jessie: In Europe, the driving variant thus far seems to be XFG, where it currently makes up for about a fourth of COVID cases, but NB.1.8.1 is on the rise there as well. NB.1.8.1 was the driving variant behind the COVID resurgence in China and other parts of Asia this year. The variants that seemed to be the most active this May in the US were LP.8.1 with 38% of cases, followed by NB.1.8.1 with 37% of cases, and XFG with 8% of cases.

This has now changed. The CDC's nowcast shows NB.1.8.1/Nimbus surged from about 2% in late April to 43% of all COVID variants on the 21st of June, making it the dominant variant in the US.

Emerson: So what exactly do we know about each of these variants?

Jessie: First up, LP.8.1 was first detected in July of last year. It's a descendant of Omicron, of course, specifically of KP.1.1.3. The World Health Organization designated LP.8.1 as a ‘variant under monitoring’ in January. Specifically, LP.8.1 has mutations at six locations in its spike protein – the protein which allows SARS-CoV-2 to attach to our cells, if you remember. One of these mutations is thought to allow this variant to spread more easily relative to other circulating variants. The other has been shown to increase binding to human lung cells in laboratory studies.

Emerson: XFG was first detected in Canada and has also achieved rapid global spread. XFG was globally designated as a ‘variant under monitoring’ by the World Health Organization on June 25, 2025. Two of XFG's or Stratus' spike mutations are thought to help it evade antibodies that target common spots on the spike protein. One of these may also help it dodge a broader class of antibodies, making it harder for the immune system to neutralize and easier for the virus to spread.

However, XFG does not bind very well to the human ACE2 receptors, which is the cell that it uses to enter our bodies, as well as some other variants, so it may not be as good as infecting cells or spreading on its own.

Jessie: And finally, the one we've all heard about, the one you've been waiting for, 🥁NB.1.8.1/ Nimbus/ Razor Blade Throat. Nimbus is currently the most dominant variant and is steadily rising in cases. The World Health Organization has classified Nimbus as a ‘variant under monitoring’ with no clear evidence yet of increased ICU admissions or mortality compared to other Omicron subvariants. This means that we don't know much about Nimbus yet, but we do know that it has quite a few mutations.

Emerson: Like its predecessors, NB.1.8.1 carries a lot of mutations in the spike protein. It's still early days for this variant, so we don't really have much data yet on what these changes mean. But a recent preprint – that is a study that has not yet been peer reviewed – offers some clues about why NB.1.8.1 may be gathering traction. Using lab-based models, researchers found that NB.1.8.1 had the strongest binding affinity to the human ACE2 receptors of several variants tested, suggesting that it might infect cells way more efficiently than earlier strains.

That same study also looked at how well antibodies from vaccinated or previously infected people could neutralize or block that variant, and the results showed that the neutralizing response of antibodies was about one and a half times lower to Nimbus compared to other recent variants like for example LP.8.1.1. This means that it's possible that a person infected with Nimbus may be more likely to pass the virus on to someone else compared to other variants.

Jessie: If we go back to those three questions and answer them with what we know about the three surging variants, number one, are they causing more severe disease?

Emerson: There are mixed opinions on that, perhaps due to how we really classify severity. For any of us who had an acute infection – and that was called mild – and then we developed along COVID, we would call the entire situation pretty severe.

For people who have had the Razor Blade Throat from Nimbus, they would say that it was worse than previous variants. In general, the World Health Organization says that it does not cause more severe disease, but I would like to know how we can know that it's not causing more severe disease or death, given that so many health systems are no longer testing for COVID anymore.

So given these variants' spike protein mutations, it can be harder for the body to detect and fight against it compared to previous variants. And mutations make the experience your body has with COVID less effective at identifying the virus and fighting it. So it basically slips under the radar so your immune system doesn't even notice it in time.

Jessie: Current evidence shows no increase in severity. Hospitalizations and deaths remain stable, albeit with weekly deaths around 300 in the US.

Emerson: Question number two that we have to ask with new variants, are they more contagious?

Jessie: Yes, especially Stratus and Nimbus seem to be extremely infectious. Their mutations of their spike proteins make that possible. We can see that in the rates that they're spreading around the globe. In May, Nimbus only made up about 5% of COVID, and on June 21st it was over 43% of cases.

In the case of Stratus, or XFG, as of Epidemiological Week 22, May 26th through June 1st, XFG represented about 23% of all sequenced SARS-CoV-2 samples globally, up from 7.5% four weeks prior.

Emerson: And question number three, do existing vaccines still work against these variants?

Jessie: Well, the World Health Organization cites laboratory data showing that the variants could have some immune escape. Which means it may be less responsive to the immunity provided by vaccines or prior infection, and suggesting a possible reduction in vaccine efficacy.

At the same time, Nimbus is a close descendant of other strains against which the vaccines have efficacy. However, the study mentioned earlier looked at how well antibodies from vaccinated or previously infected people could neutralize Nimbus. And it turns out that the neutralizing response of antibodies was around 1.5 times lower to Nimbus compared to another recent variant.

We can expect similar results with the other surging variants, as they all have quite a few relevant mutations. And this is made more complicated by the fact that the vaccine's effectiveness wanes after a few months, yet most people only get the vaccine once a year. So there's only a small window you're getting maximum protection before it wanes, and for many people, summer is just outside that window. At the moment, we just don't know how effective the vaccinations will be at protecting from these new variants.

Emerson: And that leads us to the very hot topic of vaccines.

Jessie: Yeah, so vaccines are developed to target certain COVID-19 lineages. Remember that a lineage is a collection of variants with the same ancestor. For example, COVID vaccines in the US for fall 2025 will target the JN1 lineage, which descended from Omicron. And the FDA says the preferable strain or variant to target in that lineage is LP.8.1, which accounted for 70% of US cases when they made that decision. So any variant that descended from the JN.1 lineage is going to have some protection.

So what happens if you're vaccinated with this JN.1 vaccine but get a strain of COVID that's from a different lineage? The vaccine will not be as effective at preventing severe disease since the virus has mutated so much. It will still provide some protection because the variants circulating are all descendants of Omicron. That's why it's important to stay up to date on vaccinations if your body can handle it.

Emerson: Yeah. And a big challenge with vaccine development is how quickly the virus mutates. Similar to the flu vaccine, scientists make recommendations in advance of flu season for which flu strain they think is likely to be the most infectious. And sometimes their estimates don't pan out.

With COVID, it's even trickier since there isn't really one singular COVID season. COVID is circulating year round in different wave patterns, depending on where you are in the world. The amount of COVID circulating throughout the year guarantees that mutations will happen, potentially putting the vaccine lineage that is recommended out of date. According to the World Health Organization, the currently approved COVID-19 vaccines are expected to remain effective against this year's variants – against symptomatic and severe disease.

Jessie: And by effective, we're still talking about those numbers we mentioned before...

Emerson: …the 65 to 75% and then the 10 to 15% after five to six months.

Jessie: Yeah. What does this mean?

Emerson: Well, all of this tells us very clearly that we still have to take COVID seriously and that we must continue to take precautions. Vaccines are simply not enough to protect ourselves from COVID infections, especially if we're not getting them regularly. And that means that you must do everything in our toolkits to prevent transmission to keep ourselves and our communities safe.

So, Jessie, what precautions do we generally recommend?

Jessie: Wearing a well-fitted respirator whenever you go out in public, especially in crowded and poorly ventilated spaces such as trains, train stations, shops, etc.

Use tools like CO2 monitors to monitor your risk of infection. CO2 monitors measure the amount of CO2 in the air. At rates over 800 parts per million, your risk of infection from others starts to rise significantly. So, when you reach higher CO2 rates in the air, consider opening a window or using a HEPA filter to ventilate the room to minimize your risk.

Emerson: It's also important to avoid super spreader events like concerts, festivals, anything like that, really. But if you really, really want to attend, which is totally understandable, I would recommend wearing a well-fitted respirator throughout the entire event.

Jessie: Remember that even smaller family events can turn into super spreader events if someone with COVID attends. In these situations, mitigation measures are a bit easier. For example, you can move your gatherings outside where the infection risk is nearly 19 times lower, or you can ask your family and friends to take a COVID test prior to the event.

Emerson: You can find all of this information and all of the generally recommended COVID precautions in our FAQ – Frequently Asked Questions documents that are linked in the website post in our show notes. We have one general one covering things like transmission and staying safe while living with a COVID positive person. And we have a second one that focuses solely on masking and wearing a respirator. So, it will answer questions like, which respirator should I choose? How do I know that it fits me well? How do I wear it properly? All these kinds of things because we have realized that, you know, a lot of people ask these questions repeatedly. So, I hope that this will be a resource that will be very helpful for the long COVID and the COVID cautious communities.

We also plan to make a podcast episode all about COVID precautions and the best practices of staying safe in the future. So, stay tuned not to miss it when we release it.

Jessie: Besides using these protections, what else can we do to protect ourselves?

Emerson: Well, if you are listening to this, you are probably already living a pretty COVID aware life. It's important to plan ahead. It's a bit too late for that now since we're in the middle of a growing summer surge, depending on where we are in the world. But there are some things that you could consider for future surges.

Jessie: So, one thing is plan doctors and especially dentist appointments around surges. If you have a doctor's appointment or a dentist appointment this July or August that's not super important, then consider rescheduling it to a different month where the COVID rates will be lower. Months with historically lower COVID transmission rates here in the Northern Hemisphere tend to be March through May and September to November. But this of course varies by country and region, so always keep track of your local wastewater data to know how high the infection risk is.

And if you must visit the dentist, you can try the Readimask hack for minimizing your risk while being worked on. And the Readimask is a stick on N95 that's MRI safe and you can adjust it to only cover your nose during a dental procedure – so that you breathe through your nose and not your mouth while your mouth is being worked on, and then rinse out your mouth when you're done. You can use that for any other medical appointments where the practitioner needs access to your mouth.

Emerson: However, I would like to note that Readimasks are really only available in the US and there doesn't really seem to be an equivalent to it in the rest of the world, which is pretty frustrating. So it's not really possible for us to visit the dentist safely over here, but you can find some other tips on staying safe at dentist appointments in the FAQ documents that I just mentioned. And if you happen to know of any similar masks that I don't know about that can be hacked like the Readimask that are available outside of the US, then please do let us know so that we can spread that information with the rest of the world.

Jessie: Since most hospitals and clinics no longer mask these days, even during surges – if possible, plan medical procedures where you're under anesthesia and not able to remain masked in the lower transmission months.

Emerson: And outside of all that medical stuff to pay attention to, it can also be worth it to consider taking your vacation trips or other family, social gatherings, all these kinds of things in low transmission months as well. And this can also be a bonus for your wallet. Since for a lot of these destinations, these times are considered to be out of season, which means that the costs tend to be a bit lower as well.

Jessie: Yeah, always look on the bright side!  You can also plan your vaccinations to give you the most protection during surges or when you know you'll have a high exposure risk due to personal life events. This is tough in a lot of places because COVID vaccines are restricted to once a year or sometimes it's just hard to find them. So you might have to get creative and talk to others in your community who have had success getting access to vaccines.

Emerson: And one really important thing is – make a plan for if you do test positive for COVID or if someone you live with tests positive. This includes things like having a plan for your pets in case you are too ill to meet their needs. Or to ensure that you get enough rest and time away from your workplace or school. If you're a parent, it might be useful to connect with other COVID competent parents to get ideas on managing your kids during this time of illness. The People’s CDC has a great resource on what to do if you have COVID that discusses evidence-based medications that can help prevent long COVID, as well as isolation tips for households and home remedies, masks, resting, layers of protection, all that kind of thing. Also information on when it's safe to share unfiltered air with others again.

One really important thing to mention is to plan ahead in buying equipment such as respirators, HEPA filters, etc. – all these kinds of things because during these surges, people who are not usually COVID cautious, especially now as the news is talking about the new Nimbus variant, right? These people who tend to not really take COVID seriously are now buying this equipment, which can lead to shortages. And that is often exacerbated by supply chain issues.

I noticed that myself, for nearly, I'd say a month now, my shop has not restocked the respirators that I usually buy. So I've had to try new ones, different ones because I haven't been able to access them anymore.

Jessie: And one last thing is to normalize COVID accommodations in your gatherings to lower the cognitive load associated with these gatherings. It can be stressful to try to calculate risk every time you're faced with a situation. So take the guesswork out and have some ground rules for year round and when there's a surge.

For example, I've communicated to loved ones that we likely won't join in-person gatherings when wastewater data is at a certain threshold. And I've made plans to see them during low transmission times. And I've communicated that year round, no matter what the wastewater data says, we don't share indoor unfiltered air with anyone who hasn't passed a COVID test from our metrix testing system, which I provide.

So, everyone knows that no matter what time of year, we protect ourselves, just like we put on our seatbelts in our cars even if we're driving a short distance. And we don't have to make the calculation each time and broach the topic with them each time, which can be stressful. It's a decision that has already been made, consistently followed and after a number of successful gatherings, others that are less COVID cautious are less weirded out by it.

Emerson: Yeah, so you can find a write-up just like what Jessie described in our show notes. Obviously, you'll have to adjust it to your situation and your family or friends first, but then you can either explain them to people verbally or send the adjusted version to your friends and family so that they understand what rules and accommodations they have to follow for you to be safe when spending time with them.

Well, thank you so much for listening to our podcast episode. We hope you enjoyed it and maybe learned a thing or two about COVID surges, variants, and how the virus spreads at general. We would like to start a surge series where we discuss all kinds of relevant surge topics during COVID surges. So if you enjoyed this format and would like to see more of it in the future, then please let us know. Drop us a comment or send us a DM on our socials. We generally always appreciate any and all feedback you have, so please do not hesitate to share it with us.

Jessie: And as a reminder, while our discussions offer medical-related insights, this is not medical advice. Always consult your healthcare team with any of your medical concerns.

If you'd like to connect with our community, you'll find a link to our Discord in the show notes along with our sub-stack and socials. We aim to release episodes monthly, so please subscribe and stay tuned for future episodes. Until next time, this is the COVID Longhauler's podcast, Signing off. Stay safe and see you on the next one.