BA.2: What we know about the dominant cause of Covid-19 in the US

CNN —

The highly contagious Omicron subvariant BA.2 is now the dominant coronavirus strain in the United States, causing more than half of all Covid-19 infections last week, the US Centers for Disease Control and Prevention said Tuesday.

The new numbers come from the CDC’s genomic surveillance. Based on its models, the agency says that BA.2 caused between 51% and 59% of all new Covid-19 infections in the US the week ending March 26, up from an estimated 39% of all new infections the week before.

The hardest-hit region was the Northeast, where BA.2 caused more than 70% of all cases. The South and Mountain West saw the fewest cases. BA.2 caused slightly more than one-third of infections in those regions last week.

‘We are not immune to what happens in Europe’

Though BA.2 is still just taking the stage in the US, it has had prominent runs in many other parts of the world, including Southeast Asia and the Western Pacific, and is winding down its European tour.

According to the World Health Organization, BA.2 is also the main cause of Covid-19 globally, out-muscling two other Omicron lineages, BA.1 and BA 1.1, to become the dominant strain. Since its takeover, international case counts – which had been declining since the first week of January – have been rising again.

In the UK, which has a more highly vaccinated population than the US, a combination of lifted restrictions, waning immunity and an even more contagious version of the virus have created a new BA.2 wave. Covid-19 cases, hospitalizations and deaths have been trending upward since the end of February, and now, the weekly average of new cases stands about where it was at the end of January.

BA.2 infections have not reached the peaks seen with BA.1, however. Case counts appear to be leveling off in the UK, though hospitalizations and deaths are still rising.

Throughout the pandemic, the US has followed the UK by about three weeks, so when cases began rising there, health officials here took notice.

In America, BA.2 has been gaining steam since the end of January, and case numbers have plateaued. That flattening conceals regional differences, however. In 13 states, weekly average numbers of new cases are rising, and they have stopped falling in 14 others, according to data collected by Johns Hopkins University.

It’s still not clear what this subvariant will do in the US. Even experts don’t exactly know what to expect.

“We’re not immune from what happens in Europe,” said former CDC Director Dr. Tom Frieden, who is now president and CEO of the nonprofit Resolve to Save Lives.

“In Europe, you see BA.2 becoming predominant and driving a resurgence, and the likelihood that will not happen in the US is pretty low, really,” Frieden said. “I do think part of the reason that we’re plateauing is that we’re about to start going up again.”

Frieden doesn’t think it’s a coincidence that the US Food and Drug Administration authorized additional booster shots for Americans who are 50 and older on Tuesday, the same day the CDC estimated that BA.2 was dominant.

But it’s anyone’s guess how high cases will go, whether lots of people will need hospital care, and whether the nation will continue to see breathtaking numbers of deaths.

Facing ‘a familiar uncertainty’

Most predictions about BA.2 in the US haven’t been dire.

The University of Washington’s Institute for Health Metrics and Evaluation’s Covid-19 projections, updated last week, predict that BA.2 will not drive another surge in the US.

But they say we may see something like what happened in South Africa, where BA.2 quietly replaced its cousin BA.1 as the main cause of Covid-19 infections – without a rise in cases or deaths. Instead, it drew out Omicron’s descent, causing a long tail.

Michael Osterholm, who directs the University of Minnesota’s Center for Infectious Disease Research and Policy, called the coronavirus waiting game we play every few months “a familiar uncertainty.” He dedicated his latest podcast to “all of us who remain confused about what the immediate or intermediate future looks like with Covid.”

How strong is our immunologic wall?

There are a host of reasons why it’s hard to know what BA.2 may do. The CDC estimates that 37 million Americans – about 1 in 11 – got Covid-19 over the winter, during the first Omicron wave. Many more have immunity from vaccination and boosters. So, based on random blood samples, the CDC says that 95% of Americans may now have some degree of immunity from Covid-19.

Dr. Jorge Salinas, an infectious disease expert at Stanford University, calls this an immunologic wall.

“That gives us some protection against future surges,” he said. “However, that wall deteriorates with time. The longer it goes after a wave or after vaccination, the bigger the decay of the wall.”

Studies have determined determined that BA.2 evades our vaccinations about as well as original Omicron did, so boosters are needed to restore protections against these variants. But less than half the US population 12 and older has had a recommended third dose.

Of greatest concern are adults over 65, because they are mostly likely to become severely ill with Covid-19. One out of three people over 65 in the US hasn’t had a critical third vaccine dose.

“The real problem is that so much of our population is undervaccinated seniors,” Frieden said. “That’s our Achilles heel.”

Questions about reinfection

The other variable is found in the virus itself.

Omicron threw our immune defenses for a loop. It was so different from the coronavirus strains that came before that many people who’d gotten sick with Delta or other early strains found themselves infected again.

BA.2 has about 40 amino acid changes from Omicron’s BA.1, making it about as different from its cousin as Alpha, Beta and Delta were from each other. Some have wondered whether BA.2 could reinfect people who’d had BA.1.

A large study from Denmark suggests that these kinds of reinfections are possible but rare.

The research on more than 1.8 million infections found only 1,739 cases in which people tested positive for Covid-19 twice within a two-month window. Of those, 47 were BA.1 infections that were followed by BA.2.

When researchers looked more closely, they found that these types of reinfections tended to happen to young and unvaccinated people, mostly children. And their symptoms tended to be mild.

The study was posted as a preprint, meaning that it has not yet been scrutinized by outside experts and published in a medical journal.

Studies point to high viral loads

BA.2 is exceedingly contagious. Some epidemiologists have said its basic reproduction number may be as high as 12, meaning each sick person infects an average of 12 others. That would put it on par with measles, which also spreads through the air. The basic reproduction number for BA.1 is estimated to be about 8.

In a preprint study from Sweden, researchers measured viral levels in swabs from the back of the nasal cavity. They found nearly twice as much viral RNA in samples from BA.2 patients than in those who tested positive for BA.1, “pointing to a substantial difference in viral load.”

Viral loads were about the same for Delta and BA.1 infections, they said, “whereas the increase in viral load in BA.2 cases was surprising.”

Another preprint study from Qatar picked up this difference, too.

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Laith Abu-Raddad, a professor of population sciences at Weill Cornell Medicine-Qatar, has been studying the effectiveness of vaccines and boosters against BA.1 and BA.2. A major difference between the two infections is a person’s viral load, he said.

“It’s definitely way higher” with BA.2 over BA.1, he said. His study found it to be “almost 10-fold higher.”

Instead of going deeply into the lungs, the way Delta did, the Omicron strains seem much more focused on the upper respiratory tract, where the nose meets the back of the throat, Abu-Raddad said.

He thinks that because the infection concentrates there, that also helps it spread efficiently when people talk, cough or sneeze.

A bright spot?

Perhaps one bright spot in the BA.2 picture may be severity.

Although studies in animals have suggested that BA.2 infection wasn’t entirely mild, data on human infections from the UK, Denmark and South Africa shows that BA.2 isn’t more likely to result in hospitalization when compared with BA.1.

This week, the UK Health Security Agency updated its data on vaccine effectiveness against BA.2. Up to 14 weeks, boosters were still 90% effective at preventing severe disease in people over the age of 65, pointing to an important way to make sure BA.2 doesn’t lay us low.

'Scrabble variants' now cause the majority of new Covid-19 ...

CNN —

The Omicron BA.5 subvariant is no longer the dominant cause of Covid-19 infections in the United States, according to estimates released Friday by the US Centers for Disease Control and Prevention.

Instead, a host of new sublineages – offshoots of BA.2, BA.4 and BA.5 – are now responsible for the majority of new infections in this country. Dr. Peter Hotez, director of the Center for Vaccine Development at Texas Children’s Hospital, calls these many new lineages “Scrabble variants” because they contain letters like X and Q that get high scores in the game.

The new variants descend from slightly different branches of the Omicron family tree, but they have evolved to share some of the same changes in their genomes that help them slip past our immunity against the virus.

The gaggle of new variants have been gaining ground against BA.5, which has dominated Covid-19 infections in the United States since July. BA.5 now accounts for 49.6% of new infections in this country.

Two variants, BQ.1 and BQ.1.1, have been growing especially fast. At the beginning of October, each one accounted for about 1% of new infections in the United States, but they have been roughly doubling in prevalence each week. Together, they now account for more than 1 in 4 new Covid-19 infections nationwide, according to CDC data.

BQ.1 is causing about 14% of new infections; BQ.1.1. is causing 13% of new infections. BA.4.6 is causing another 10%. BF.7 accounts for 7.5% of newly diagnosed Covid-19. A slew of other new variants accounts for smaller pieces of the Covid-19 pie.

These variants are not evenly distributed across the US. BQ.1.1 is now causing about 1 in 5 new Covid-19 infections in the Northeast, where cases and hospitalizations are rising. But that strain is causing just 3% of new Covid-19 infections in the Pacific Northwest.

These variants are slightly different from each other, but they all carry some of the same key mutations that help them skirt immunity from vaccines and past infections. This makes them more likely to lead to breakthrough infections and reinfections.

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In a statement released Friday, the World Health Organization’s Technical Advisory Group on SARS-CoV-2 Virus Evolution said the most mutated families of the rising subvariants – XBB and BQ.1 – aren’t different enough from Omicron to be considered separate variants of concern.

XBB was detected in the United States in September, but it is not causing a significant number of cases in this country. It is particularly widespread in Singapore, where it is now the dominant circulating strain.

“The two sublineages remain part of Omicron, which continues to be a variant of concern,” the group said in a statement.

Covid-19 reinfections may increase the likelihood of new health ...

CNN —

Repeatedly catching Covid-19 appears to increase the chances that a person will face new and sometimes lasting health problems after their infection, according to the first study on the health risks of reinfection.

The study, which is based on the health records of more than 5.6 million people treated in the VA Health System, found that, compared with those with just one Covid-19 infection, those with two or more documented infections had more than twice the risk of dying and three times the risk of being hospitalized within six months of their last infection. They also had higher risks for lung and heart problems, fatigue, digestive and kidney disorders, diabetes and neurologic problems.

The findings come as a fresh wave of coronavirus variants, notably Omicron’s BA.5, have become dominant in the United States and Europe, causing cases and hospitalizations to rise once again. BA.5 caused about 54% of cases nationwide last week, doubling its share of Covid-19 transmission over the past two weeks, according to data posted Tuesday by the US Centers for Disease Control and Prevention.

BA.5 carries key mutations that help it escape antibodies generated by both vaccines and prior infection, leaving many people vulnerable to reinfection.

Dr. Ziyad Al-Aly, a clinical epidemiologist at Washington University in St. Louis, led the research, which was posted as a preprint ahead of peer review. He said he decided to do it after watching reinfections become more and more common among his own patients.

“If you asked me about reinfection maybe a year and a half ago, I would tell you that maybe I have a patient here or there, but it’s really, really rare,” Al-Aly said. That’s not true anymore, though.

“So we asked a simple question that if you got Covid before and now you’re on your second infection, does this really add risk? And the simple answer is that it does.”

Tallying the risks of reinfections

Al-Aly and his team compared the health records of more than 250,000 people who had tested positive for Covid-19 one time with records from 38,000 others who had two or more Covid-19 infections documented in their medical records. More than 5.3 million people with no record of a Covid-19 infection were used as the control group.

Among those with reinfections, 36,000 people had two Covid-19 infections, roughly 2,200 had caught Covid-19 three times, and 246 had been infected four times.

Common new diagnoses after reinfections included chest pain, abnormal heart rhythms, heart attacks, inflammation of the heart muscle or the sac around the heart, heart failure and blood clots. Common lung issues included shortness of breath, low blood oxygen, lung disease, and accumulation of fluid around the lungs, Al-Aly said.

The study found that the risk of a new health problem was highest around the time of a Covid-19 reinfection, but it also persisted for at least six months. The increased risk was present whether or not someone had been vaccinated, and it was graded – meaning it increased with each subsequent infection.

Al-Aly said that’s not what people really think will happen when they get Covid a second or third time.

“There is this idea that if you had Covid before, your immune system is trained to recognize it and is more equipped to fight it, and if you’re getting it again, maybe it doesn’t affect you that much, but that’s not really true,” he said.

Al-Aly said that doesn’t mean there aren’t people who have had Covid and done just fine; there are lots of them. Rather, what his study shows is that each infection brings new risk, and that risk adds up over time, he said.

Even if a person has half the risk of developing lasting health problems during a second infection than they did during their first infection, he said, they still wind up with 50% more risk of problems than someone who didn’t get Covid-19 a second time.

The study has some important caveats. Al-Aly says it was more common to see reinfections among people who had existing risks because of their age or underlying health. That shows that reinfection may not be random, and it could be that the health risks linked to reinfections aren’t, either.

“It is possible that sicker individuals or people with immune dysfunction are at higher risk of reinfection and adverse health outcomes after reinfection,” Al-Aly said.

He wasn’t interested in trying to isolate the pure effects of reinfection but wanted to understand how repeated infections are affecting the people who get them.

“The most relevant question to people’s lives is, if you get reinfected, does it add to your risk of acute complications and long Covid, and the answer is a clear yes and yes,” he said.

The study is observational, which means it can’t determine cause and effect.

Al-Aly says the researchers saw these increased risks even after they weighted the data to account for the effects of age, sex, medication use and the person’s underlying health before they got Covid-19.

Covid-19 continues to surprise

Experts who were not involved in the research say it is compelling.

“There is this idea that I think a lot of people have that ‘if I survived my first infection, that I’m really going to be just fine the second time. There really shouldn’t be any problem,’ ” said Dr. Daniel Griffin, an instructor in clinical medicine at Columbia University.

“The popular wisdom, right, is that reinfections are mild, nothing to worry about, nothing to see here,” Griffin said of the study on the podcast “This Week in Virology.” But that’s not really being borne out, he said.

This is not how it’s supposed to work. Even when viruses shape-shift – as influenza does – our immune system generally retains its memory of how to recognize and fight off some part of them. They may still make us ill, but the idea is that our prior immunity is there to mount some of kind of defense and keep us from serious harm.

With coronaviruses, and especially SARS-CoV-2 coronaviruses, the hits just keep on coming.

“A year later, you can get reinfected with the same coronavirus the second time. It is not clear that that second infection can be more mild, because coronaviruses intrinsically have the ability to interfere with long-lasting lifetime immunity,” Griffin told CNN.

Griffin says he’s seen Covid-19 reinfections go both ways. Sometimes, the second or third is milder for his patients, but sometimes it’s not.

How does that compare with other respiratory infections?

Early in the pandemic, people would get Covid, and three months would go by when they were pretty well protected, he said. But now, those reinfections are happening more frequently, no doubt because of the rapid changes to the virus. He says he’s seen some people infected four times in the past two years.

“We don’t really see much of that with the flu,” Griffin said.

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As for what people should be doing now with regard to this risk, Dr. Michael Osterholm, who directs the Center for Infectious Disease Research and Policy at the University of Minnesota, says Americans are really done with the pandemic. That doesn’t mean that the pandemic is done with us, though.

Osterholm said he has three close friends who recently went to a restaurant for the first time since the pandemic started. All of them tested positive within 72 hours of that restaurant visit.

If you’re at higher risk of serious illness or you just want to avoid getting sick, it’s a good time to be wearing an N95 mask in public places, he says.

“People don’t want to hear it, but that’s the reality. We’re seeing this resurgence, and we’re seeing increasing numbers of vaccine failures. Clearly, that’s a major concern,” he said.

Could the new BA.2 variant cause another surge? A medical expert ...

CNN —

A subvariant of Omicron, BA.2, is leading to a new wave of Covid-19 infections across Europe. Cases in the United Kingdom, Germany, the Netherlands and other countries are going up, driven by this very contagious coronavirus strain.

The proportion of Covid-19 cases due to BA.2 is rising in the United States, too. The US Centers for Disease Control and Prevention now estimates that 35% of new coronavirus cases are due to this subvariant. At the same time, restrictions are being lifted, and not a single US state requires mask mandates anymore (though masks are still required in some settings, including airports, public transportation, hospitals, nursing homes, and some schools and workplaces).

How worried should people be about the BA.2 variant? Will vaccines protect against it? What if someone contracted a previous variant – could they become reinfected? Is BA.2 milder than previous versions, and if so, should people try to get it? Could BA.2 cause another surge in the US, and is it time for restrictions to be put back into place?

To help us with these questions, I spoke with CNN Medical Analyst Dr. Leana Wen, an emergency physician and professor of health policy and management at the George Washington University Milken Institute School of Public Health. She is also author of “Lifelines: A Doctor’s Journey in the Fight for Public Health.”

CNN: What do we know about BA.2, and how worried should we be about it?

Dr. Leana Wen: With any new variant or subvariant, we need to ask three questions: Is it more contagious? Does it cause more severe disease? And does it evade the protection of our vaccines?

BA.2 is related to BA.1, which is the original Omicron subvariant that led to the huge surge in cases over the winter here in the United States and across Europe. BA.1 swept through communities because of how contagious it is. BA.2 appears to be even more contagious than BA.1. The UK Health Security Agency estimates that BA.2 is growing 80% faster than BA.1. Here in the US as well, BA.2 appears to be on its way to overtaking BA.1 to become the dominant variant.

The good news is that BA.2 does not seem to cause more severe illness than BA.1. Researchers from the UK and Denmark have found BA.2 causes a level of hospitalization that’s comparable to that of BA.1, which is less likely to result in severe illness than the previously dominant Delta variant.

In addition, the vaccines we have are still effective. While vaccination may not protect as well against infection with BA.1 and BA.2, the effectiveness in that regard is partially restored with a booster dose, and the vaccines continue to provide very good protection against severe illness due to both Omicron subvariants.

What all of this says to me is that public health experts should follow the rise of BA.2 in the US closely, but that most people should not be worried. It’s likely that the US will see an increase in Covid-19 cases in the coming weeks, as this is the pattern we’ve seen before – that we lag behind the UK and Europe by a few weeks, so the increase they are seeing could be mirrored here. However, most people who are vaccinated, and in particular if they are boosted, are unlikely to become severely ill due to BA.2. Our government officials should prepare for what could be coming and increase the availability of tests and treatments, and continue to urge people to get vaccines and boosters. But I don’t think this is something that the general public should be overly concerned about at this time.

CNN: Does that mean people can proceed with spring break and other travel plans, or do they need to postpone them?

Wen: I don’t think travel plans need to be put on hold. To be sure, there is uncertainty, as some places might have low rates of Covid-19 now but may have increased rates when you travel. However, that may be the case for the foreseeable future. Very few activities that we do have no risk. Traveling certainly entails risk, but you can reduce that risk by making sure you are vaccinated and boosted. Wearing a mask in crowded indoor settings further reduces risk. In the United States, follow the CDC guidance and make sure to wear a mask in areas that have high Covid-19 community levels. If you are planning international travel, know the rules, including whether you have to have proof of vaccination or a recent negative test.

Before social get-togethers, immunocompromised people may want to request that others get tested for Covid-19, CNN Medical Analyst Dr. Leana Wen suggests. Eric Lee/Bloomberg/Getty Images

CNN: Are there certain people who should be concerned about BA.2?

Wen: Individuals who are very vulnerable to severe illness from Covid-19 despite vaccination should be concerned about the coronavirus in general, as they are about other infectious pathogens. For most people, Covid-19 infection will result in mild illness, but in some people –those who are moderately or severely immunocompromised or with multiple underlying medical conditions – the infection still could result in hospitalization. BA.2 may not cause more severe disease than BA.1, but because of how contagious it is, people who are particularly vulnerable will want to keep taking additional precautions. That includes wearing a high-quality mask (N95, KN95 or KF94) in all indoor public settings, avoiding large crowds and traveling for essential reasons only. Before getting together with other people, they may wish to request that the others are tested for Covid-19.

CNN: If someone previously had Omicron, are they protected against BA.2?

Wen: The World Health Organization has said that infection with BA.1 continues to provide protection against BA.2. Reinfection with BA.2 after having BA.1 is rare.

Most people don’t find out what variant they had, though this could be estimated based on when they got infected. If someone found out that they had Covid-19 during the initial Omicron surge, it’s likely they had BA.1. In that case, especially if they are vaccinated too, they are very unlikely to contract BA.2.

However, if someone was previously infected during another wave, for example, while Delta was predominant, they could still contract BA.1 or BA.2. This is another reason why vaccination is so crucial, because the combination of vaccination and prior infection provides more consistent and more durable protection than prior infection alone.

CNN: Omicron is a milder variant than previous variants. In that case, should people try to contract BA.2 just to get it over with?

Wen: In general, it is not a good strategy to try to contract an illness. Omicron is less likely to result in severe disease compared with Delta, but it still causes severe illness in some people. In addition, even mild illness may be very unpleasant and result in feeling unwell, missing work and being unable to care for family members for days. You could also infect other people, and there is the possibility of long-haul symptoms as well. A better strategy is to make sure to get the vaccine and booster so that if you were to encounter BA.2 (or another variant of Covid-19), you are as well protected as possible.

CNN: Could BA.2 cause another surge in the US, and if so, should restrictions come back now?

Wen: BA.2 could certainly lead to another uptick in Covid-19 infections in the US. There are already some signs that the sharp decline in new cases is leveling out, and if the US follows Europe, as it has before, a rise in cases could be weeks away.

That said, I don’t think it means we need to reinstate restrictions. The goal of vaccination is to decouple infections from hospitalizations and severe illness. If there is a surge in infections but hospitalizations don’t rise to the point that our health care system becomes overwhelmed, then I think government-imposed mandates are not warranted. Here, the new CDC guidelines are very helpful, as they take into account severe illness – severe enough to cause hospitalizations – as the metric for masking, not just any infection.

Of course, just because the government isn’t requiring masks doesn’t mean that individuals shouldn’t mask or take other precautions. At this point in the pandemic, people should make decisions based on their own medical circumstances and tolerance of risk.

Coronavirus: As BA.2 subvariant of Omicron rises, lab studies point ...

CNN —

The BA.2 virus – a subvariant of the Omicron coronavirus variant – isn’t just spreading faster than its distant cousin, it may also cause more severe disease and appears capable of thwarting some of the key weapons we have against Covid-19, new research suggests.

New lab experiments from Japan show that BA.2 may have features that make it as capable of causing serious illness as older variants of Covid-19, including Delta.

And like Omicron, it appears to largely escape the immunity created by vaccines. A booster shot restores protection, making illness after infection about 74% less likely.

BA.2 is also resistant to some treatments, including sotrovimab, the monoclonal antibody that’s currently being used against Omicron.

The findings were posted Wednesday as a preprint study on the bioRxiv server, before peer review. Normally, before a study is published in medical journal, it is scrutinized by independent experts. Preprints allow research to be shared more quickly, but they are posted before that additional layer of review.

“It might be, from a human’s perspective, a worse virus than BA.1 and might be able to transmit better and cause worse disease,” says Dr. Daniel Rhoads, section head of microbiology at the Cleveland Clinic in Ohio. Rhoads reviewed the study but was not involved in the research.

The US Centers for Disease Control and Prevention is keeping close watch on BA.2, said its director, Dr. Rochelle Walensky.

“There is no evidence that the BA.2 lineage is more severe than the BA.1 lineage. CDC continues to monitor variants that are circulating both domestically and internationally,” she said Friday. “We will continue to monitor emerging data on disease severity in humans and findings from papers like this conducted in laboratory settings.”

BA.2 is highly mutated compared with the original Covid-causing virus that emerged in Wuhan, China. It also has dozens of gene changes that are different from the original Omicron strain, making it as distinct from the most recent pandemic virus as the Alpha, Beta, Gamma and Delta variants were from each other.

Kei Sato, a researcher at the University of Tokyo who conducted the study, argues that these findings prove that BA.2 should not be considered a type of Omicron and that it needs to be more closely monitored.

“As you may know, BA.2 is called ‘stealth Omicron,’ ” Sato told CNN. That’s because it doesn’t show up on PCR tests as an S-gene target failure, the way Omicron does. Labs therefore have to take an extra step and sequence the virus to find this variant.

“Establishing a method to detect BA.2 specifically would be the first thing” many countries need to do, he says.

“It looks like we might be looking at a new Greek letter here,” agreed Deborah Fuller, a virologist at the University of Washington School of Medicine, who reviewed the study but was not part of the research.

Mixed real-world data on subvariant’s severity

BA.2 has been estimated to be about 30% more contagious than Omicron, according to the World Health Organization. It has been detected in 74 countries and 47 US states.

The US Centers for Disease Control and Prevention estimates that about 4% of Americans with Covid-19 now have infections caused by BA.2, but many other parts of the world have more experience with this variant. It has become dominant in at least 10 other countries: Bangladesh, Brunei, China, Denmark, Guam, India, Montenegro, Nepal, Pakistan and the Philippines, according to World Health Organization’s weekly epidemiological report.

However, there’s mixed evidence on the severity of BA.2 in the real world. Hospitalizations continue to decline in countries where BA.2 has gained a foothold, like South Africa and the UK. But in Denmark, where BA.2 has become the leading cause of infections, hospitalizations and deaths are rising, according to WHO.

Resistant to monoclonal antibody treatments

The new study found that BA.2 can copy itself in cells more quickly than BA.1, the original version of Omicron. It’s also more adept at causing cells to stick together. This allows the virus to create larger clumps of cells, called syncytia, than BA.1. That’s concerning because these clumps then become factories for churning out more copies of the virus. Delta was also good at creating syncytia, which is thought to be one reason it was so destructive to the lungs.

When the researchers infected hamsters with BA.2 and BA.1, the animals infected with BA.2 got sicker and had worse lung function. In tissues samples, the lungs of BA.2-infected hamsters had more damage than those infected by BA.1.

Similar to the original Omicron, BA.2 was capable of breaking through antibodies in the blood of people who’d been vaccinated against Covid-19. It was also resistant to the antibodies of people who’d been infected with Covid-19 early in the pandemic, including Alpha and Delta. And BA.2 was almost completely resistant to some monoclonal antibody treatments.

But there was a bright spot: Antibodies in the blood of people who’d recently had Omicron also seemed to have some protection against BA.2, especially if they’d also been vaccinated.

And that raises an important point, Fuller says. Even though BA.2 seems more contagious and pathogenic than Omicron, it may not wind up causing a more devastating wave of Covid-19 infections.

“One of the caveats that we have to think about as we get new variants that might seem more dangerous is the fact that there’s two sides to the story,” Fuller says.

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The virus matters, she says, but as its would-be hosts, so do we.

“Our immune system is evolving as well. And so that’s pushing back on things,” she said.

Right now, she says, we’re in a race against the virus, and the key question is, who’s in the lead?

“What we will ultimately want is to have the host be ahead of the virus. In other words, our immunity, be a step ahead of the next variant that comes out, and I don’t know that we’re quite there yet,” she said.

For that reason, Fuller says, she feels like it’s not quite time for communities to lift mask mandates.

“Before this thing came out, we were about 10 feet away from the finish line,” she said. “Taking off the masks now is not a good idea. It’s just going to extend it. Let’s get to the finish line.”

Why the Omicron offshoot BA.5 is a big deal | CNN

CNN —

Once again, Covid-19 seems to be everywhere. If you feel caught off-guard, you aren’t alone.

After the Omicron tidal wave washed over the United States in January and the smaller rise in cases in the spring caused by the BA.2 subvariant, it might have seemed like the coronavirus could be ignored for a while. After all, the US Centers for Disease Control and Prevention estimated in December that nearly all Americans had been vaccinated or have antibodies from a past infection. Surely all that immunity bought some breathing room.

But suddenly, many people who had recovered from Covid-19 as recently as March or April found themselves exhausted, coughing and staring at two red lines on a rapid test. How could this be happening again – and so soon?

The culprit this time is yet another Omicron offshoot, BA.5. It has three key mutations in its spike protein that make it both better at infecting our cells and more adept at slipping past our immune defenses.

In just over two months, BA.5 outcompeted its predecessors to become the dominant cause of Covid-19 in the United States. Last week, this subvariant caused almost 2 out of every 3 new Covid-19 infections in this country, according to the latest data from the CDC.

Lab studies of antibodies from the blood of people who’ve been vaccinated or recovered from recent Covid-19 infections have looked at how well they stand up to BA.5, and this subvariant can outmaneuver them. So people who’ve had Covid as recently as winter or even spring may again be vulnerable to the virus.

“We do not know about the clinical severity of BA.4 and BA.5 in comparison to our other Omicron subvariants,” CDC Director Dr. Rochelle Walensky said at a White House Covid-19 Response Team briefing Tuesday. “But we do know it to be more transmissible and more immune-evading. People with prior infection, even with BA.1 and BA.2, are likely still at risk for BA.4 or BA.5.”

A ‘full-on’ wave

The result is that we’re getting sick in droves. As Americans have switched to more rapid at-home tests, official case counts – currently hovering around 110,000 new infections a day – reflect just a fraction of the true disease burden.

“We estimate that for every reported case there are 7 unreported,” Ali Mokdad, professor of health metrics sciences at the University of Washington’s Institute for Health Metrics and Evaluation, wrote in an email.

Other experts think the wave could be as much as 10 times higher than what’s being reported now.

“We’re looking at probably close to a million new cases a day,” Dr. Peter Hotez said on CNN. “This is a full-on BA.5 wave that we’re experiencing this summer. It’s actually looking worse in the Southern states, just like 2020, just like 2021,” said Hotez, dean of the National School of Tropical Medicine at the Baylor College of Medicine in Houston.

That puts us in the range of cases reported during the first Omicron wave, in January. Remember when it seemed like everyone everywhere got sick at the same time? That’s the situation in the United States again.

It may not seem like a very big deal, because vaccines and better treatments have dramatically cut the risk of death from Covid-19. Still, about 300 to 350 people are dying on average each day from Covid-19, enough to fill a large passenger jet.

“That is unacceptable. It’s too high,” Dr. Ashish Jha, coordinator for the White House Covid-19 Response Team, said at Tuesday’s briefing.

Daily hospitalizations are also climbing in the United States. The fraction of patients needing intensive care is up by about 23% over the past two weeks. And other countries are experiencing BA.5 waves, too.

“I am concerned that cases of Covid-19 continue to rise, putting further pressure on stretched health systems and health workers. I am also concerned about the increasing trend of deaths,” said Tedros Adhanom Ghebreyesus, director-general of the World Health Organization, at a news briefing Tuesday after the agency’s decision to maintain its emergency declaration for Covid-19.

The pandemic, he said, is “nowhere near over.”

What’s at stake with continued spread

There are also more insidious health risks to consider. A recent preprint study that compared the health of people who’d been infected one or more times with Covid-19 found that the risk of new and sometimes lasting health problems rose with each subsequent infection, suggesting that reinfections are not necessarily benign.

Although vaccination reduces the risk of getting long Covid, a certain percentage of people have lasting symptoms after a breakthrough infection.

That’s another reason why high numbers of Covid-19 cases are a big deal: Because the virus is still spreading wildly, it has every opportunity to mutate to make even fitter and more infectious versions of itself. It’s doing this faster than we can change our vaccines, leaving us stuck in the Covid-rinse-repeat period of the pandemic.

On Tuesday, Dr. Anthony Fauci, director of the National Institutes of Allergy and Infectious Diseases, pleaded with Americans to use all available tools to stop the spread of the virus, including masking, ventilation and social distancing.

“We need to keep the levels of virus to the lowest possible level, and that is our best defense. If a virus is not very robustly replicating and spreading, it gives it less of a chance of a mutation, which gives it less of a chance of the evolving of another variant,” Fauci said in a news briefing.

In fact, this is already happening.

Meet BA.2.75

Even as the US comes to terms with BA.5, variant hunters around the world are closely watching another Omicron descendant, BA.2.75. It’s been detected in about 10 countries, including the United States, and seems to be growing quickly in India.

BA.2.75 has nine changes in its spike region that distinguish it from BA.2 and about 11 changes compared with BA.5, according to Tom Peacock, a virologist at Imperial College London.

Several of the mutations in BA.2.75 are in a region of the spike protein known to be an important place for antibodies to bind to stop the virus, said Ulrich Elling, a scientist at the Austrian Academy of Sciences who monitors coronavirus variants for that country.

There’s little information to go on: It’s still not known, for example, how BA.2.75 may compete against BA.5 or whether it causes more severe illness. But experts say it has all the hallmarks of a variant that could go global.

“It spread to many different countries already, so we know that it has some sort of staying power,” said Shishi Luo, associate director of bioinformatics and infectious disease for Helix Labs, which decodes virus samples for the CDC and other clients.

Because of that, and because of changes in the region of the virus that our antibodies look for to shut it down, “we sort of know ahead of time that this one will cause some trouble,” Luo said.

Based on what we know now, she expects that this subvariant could drive a fall Covid-19 wave in the United States.

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In the meantime, Jha said, people should get boosters that are available to them to keep their immunity as strong as possible. US health officials emphasized that people who are boosted now will still be able to get an updated shot this fall that includes the BA.4 and BA.5 strains.

Jha specifically urged Americans who are 50 and older, “if you’ve not gotten a vaccine shot this year, go get one now. It could save your life,” he said.

New studies bring BA.2 variant into sharper focus | CNN

CNN —

On the heels of concerning new lab and animal experiments suggesting that BA.2 may be capable of causing more severe disease than the original Omicron strain, two new studies are helping to show how well human immunity is defending against this strain in the real world.

BA.2 is about 30% more transmissible than the original Omicron variant, BA.1, according to early studies from the UK and Denmark, and it is now causing about 1 in 5 Covid-19 cases worldwide, according to the World Health Organization.

Even as Covid-19 cases have been dropping around the world, the relative proportion of cases caused by BA.2 has been increasing. It is outcompeting the original Omicron strain in at least 43 countries, prompting fears of another devastating pandemic wave.

“As of now, I don’t think that we need to sound a global alarm. But I do think that we need to pay attention to BA.2 because it does appear to have a growth advantage over BA.1,” says Dr. Dan Barouch, director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center in Boston.

Like the BA.1 strain, BA.2 also has features that help it escape some immunity from vaccines and from most monoclonal antibody treatments, though recent boosters improve personal protection and antiviral pills are still expected to work against this subvariant.

Now new studies are providing some reassurance that while BA.2 may overtake its genetically distant cousin, it won’t likely lead to greater numbers of hospitalizations and deaths.

“The situation that we’re seeing on the ground, and I get this from talking to a number of my colleagues who actually do the genomic surveillance, is BA.2 is kind of creeping up in terms of numbers, but it’s not the meteoric rise that we saw with BA.1,” said Angela Rasmussen, a virologist at the Vaccine and Infectious Disease Organization at the University of Saskatchewan in Canada.

That’s because in many countries like the US, UK, and Denmark, BA.2 has hit speed bumps left in its wake by BA.1, which was already very contagious.

“It’s so soon after that initial BA.1 peak that you have a lot of people who were either vaccinated or boosted … [or] got Omicron, and so right now all of those people will have relatively high titers of antibodies, neutralizing antibodies that will protect against infection,” Rasmussen says.

The new studies are preprints, which means they were posted to an online library of medical research before being reviewed by outside experts and published in medical journals.

No increase in hospitalizations

The first new study comes from South Africa, where BA.2 grew rapidly, rising from 27% to 86% of new Covid-19 infections over the course of a single week in February. Researchers looked at cases tied to more than 95,000 positive Covid-19 tests. Among these, roughly equal proportions of people were hospitalized for their infections – roughly 3.6% of people who had presumed BA.2 infections compared to 3.4% of those with signs infections caused by BA.1.

After researchers accounted for things that might influence a person’s risk of severe disease, such as older age, they found no difference in the risk for hospitalization between people infected by BA.1 and those infected by BA.2. Roughly one-quarter of people hospitalized with both BA.1 and BA.2 infections were fully vaccinated.

Those findings echo hospitalization studies from Denmark, where BA.2 is also the predominant cause of Covid-19 infections.

The lead researcher on the South African study, Dr. Nicole Wolter, says that while it’s difficult to say how the South African experience with this variant may translate to other countries, what they’re seeing from BA.2 after their fourth wave isn’t a second peak, but a longer tail.

“We have seen an extended wave which has currently plateaued at a higher level than we have seen in previous inter-wave periods,” Wolter wrote in an email to CNN. “This may however also be influenced by schools opening following the December holiday period and a general relaxing of restrictions,” wrote Wolter, who is a principal medical scientist at the National Institute for Communicable Diseases in Johannesburg.

Though cases have stayed at a high level, and most are now caused by BA.2, hospitalizations have continued to decline.

What about reinfection risk?

The second new study, from Denmark’s Statens Serum Institut – the country’s equivalent to the US Centers for Disease Control and Prevention – looked at the risk of reinfection with BA.2 after recovery from a Covid-19 infection caused by other recent variants, including Delta and BA.1.

The study found that people who’ve recently had a Covid-19 infection caused by Omicron or Delta can be reinfected by the emerging BA.2 subvariant, but such cases appear to be uncommon, afflict mostly those who are unvaccinated and result in mostly mild infections.

BA.2 is currently the dominant cause of Covid-19 in Denmark. It overtook BA.1 during the second week of January there.

To look at reinfection risk, researchers combed through more than 140,000 viral genomes that were sequenced from infections during the period when Omicron became dominant (late November to mid-February 2022) to find people who had a new positive test 20 to 60 days after a previous one.

They found a total of 263 reinfections, with 190 of those caused by the BA.2 variant. In 140 cases, the person was reinfected by BA.2 after an infection caused by the Delta variant. There were 47 cases where people were first infected by BA.1 (the original Omicron variant) followed by the BA.2 subvariant.

Researchers then did a more in-depth analysis of those 47 reinfections where BA.2 followed BA.1. Most of the individuals who were reinfected were young – 30 were under age 20. None of the reinfected individuals was over age 40 and nearly all – 42 of the 47 individuals – were unvaccinated.

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For the most part, reinfections were mild; 28 people had no symptoms or mild symptoms. Five people experienced symptoms that were characterized as moderate, akin to flu-like symptoms. There were no hospitalizations or deaths reported among reinfected individuals.

The study shows that “reinfection can happen with people who recently recovered from BA;1, but it’s pretty rare. And in all those cases, it wasn’t severe,” says Rasmussen, who reviewed the study but was not involved in the research.

What that means she says is that while BA.2 reinfection is a risk, it is a small risk relative to the entire population, and “that recent immune boost caused by either boosters, or recent Omicron infection is largely going to protect most of the population against it,” she said.

BA.2, the newly detected version of Omicron, is not a cause for alarm ...

CNN —

A new spinoff of the Omicron variant of the coronavirus is getting attention from scientists as it becomes the dominant cause of Covid-19 infections in some parts of the world.

Experts say there’s no reason to panic over the lineage, called BA.2, which was first identified in early December and has since spread to 49 countries including the United States.

“Among all the lineages of Omicron, this is the one showing a higher increase of cases. But we have to be careful in interpreting that, because higher increases from a very low number are easier to observe,” said Ramon Lorenzo-Redondo, assistant professor of medicine for infectious diseases at Northwestern University Feinberg School of Medicine in Chicago.

Like the more familiar version of Omicron, BA.2 has a large number of changes – about 20 –concentrated in the spike protein, the part of the virus that’s targeted by vaccines.

Unlike Omicron, however, it doesn’t cause a certain signature on lab tests called an s-gene target failure, meaning it can look like other SARS-CoV-2 variants on a first screen. That has some calling it “the stealth variant.”

But Lorenzo-Redondo says that nickname has caused people to think that it can’t be detected in lab tests, which isn’t the case.

“There has been confusing messaging about this subject. Both FDA-approved lab-based and at-home tests should detect this lineage, as well as the other Omicron (sublineage), BA.1,” he said.

There’s no indication that BA.2 causes more severe disease or spreads more easily than the original strain of Omicron. A report released Thursday by the UK’s Health Security Agency offers additional reassurance, suggesting that current vaccines protect about as well against BA.2 as they do against the original Omicron variant, with better protection against symptoms — an average of about 70% – two weeks after a booster.

The version of the virus that researchers have named Omicron includes multiple viral families. The BA.1 family is the one causing nearly all Omicron infections in the U.S. Now, a second family, the BA.2 clade, is starting to gain ground in other countries, notably India and Denmark.

In Denmark, BA.2 now accounts for about half of all new Covid-19 cases, according to a recent statement from Denmark’s Statens Serum Institute.

On Thursday, Dr. Sujeet Kumar Singh, director of India’s National Centre for Disease Control, said that BA.2 had become the dominant strain there.

BA.2 has also been picked up in South Africa and the United Kingdom, where it has been designated a variant under investigation by the UK’s Health Security Agency. A variant under investigation is one that’s spreading in the country and being monitored because it may spread more easily from person to person or have features that make it more resistant to treatments or vaccines.

In the US, roughly 100 cases caused by BA.2 have been reported from at least 20 states, according to the sequence-sharing website GISAID.org.

BA.2 currently accounts for less than 1% of US Covid-19 cases, according to Outbreak.info, a Scripps Research data project.

At Houston Methodist Hospital in Texas, researchers are sequencing the viral genomes of every positive Covid-19 case they find. Out of more than 4,000 genomes sequenced since the first of the year, they’ve found only three cases of the BA.2 sublineage, said Dr. Wesley Long, medical director of microbiology.

Will it take off here the way it has in India and Denmark? “I think it’s still too early to tell,” Long says.

Viruses change, or mutate, all the time. Most of these changes aren’t harmful. But occasionally, a virus will change in a way that helps it become more competitive. It might transmit from host to host more quickly, for example, or bind to cells more easily.

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Long says it’s hard to know why BA.2 is gaining ground in certain countries. It could be that it has some kind of advantage over the original Omicron variant, or perhaps both BA.1 and BA.2 were introduced around the same time, so they were able to spread at about the same rate.

But he says scientists will be watching those countries closely to see how the situation plays out over the next few weeks.

Scientists say the new Omicron spinoff is not surprising and, in fact, was anticipated, given that about half of the world’s population still hasn’t been vaccinated against the coronavirus.

“I’d be very surprised, with the current state of the global population in terms of immune status, if we didn’t see more variants emerge,” says Angela Rasmussen, a virologist with the Vaccine and Infectious Disease Organization at the University of Saskatchewan.

COVID: Omicron variant, BA.5 symptoms and more updates on the ...

CDC data shows the omicron subvariant BA.5 has become the dominant strain in the country

A new study shows COVID was the third leading cause of death in the US from March 2020 to Oct. 2021

Barring the emergence of a new variant, experts say the worst of COVID-19 may finally be behind us

Coronavirus cases are rising in the U.S. – again.

Eighteen states reported more cases in the week of June 30-July 7 than in the week before, according to a USA TODAY analysis of Johns Hopkins University data.

That led to a rise in hospitalizations: Hospitals in 40 states reported more COVID-19 patients than a week earlier. Thirty-eight states had more patients in intensive care beds, and 17 states reported more deaths than a week earlier.

Although the increase in cases doesn’t approach the meteoric levels of previous waves, health experts said what's recorded is likely an undercount because of underreported test results.

Here’s everything to know about the coronavirus and the state of the pandemic.

How many Americans are vaccinated against COVID-19?

The Centers for Disease Control and Prevention reported about 66% of eligible people in the U.S. have been fully vaccinated against COVID-19, and about 47% have gotten at least one booster.

In June, federal authorities authorized a COVID-19 vaccine for children as young as 6 months. The CDC has yet to report vaccination rates for that population, but polling data from April found only 18% of parents said they would vaccinate their younger children right away, 27% said they definitely wouldn’t, and 38% said they’d wait and see.

Looking at vaccination rates among the next age group, 5 to 11 years, health experts worry vaccine uptake among children may be slow. As of June 29, the American Academy of Pediatrics reported 29% of 5- to 11-year-olds received both doses of the COVID-19 vaccine.

Experts advised parents to jump on lifesaving vaccines sooner rather than later. A modeling study published in JAMA Network Open this week found vaccines may have prevented about 235,000 COVID-19-related deaths among people over 18 from Dec. 1, 2020, to Sept. 30, 2021.

"If you want your child fully protected in the fall ... I wouldn’t wait," said Richard Besser, a pediatrician and president and CEO of the Robert Wood Johnson Foundation.

Omicron BA.4 and BA.5 variant: What to know

CDC data shows the omicron subvariant BA.5 has become the dominant strain in the country, making up more than 54% of sequenced COVID-19 cases.

The next most-dominant subvariant is BA.2.12.1, which makes up about 27% of sequenced cases, followed by BA.4 at about 17%.

Although it has been a slow rise since the winter wave, health experts said the proportion of subvariants among new cases increases every week.

“These subvariants have been with us for the past two months already,” said David Dowdy, an epidemiologist at the Johns Hopkins Bloomberg School of Public Health. “It’s a relatively slow increase that we’ve seen relative to the original omicron wave, which happened over the course of the month.”

Health experts said symptoms of BA.4 and BA.5 align closely with symptoms from other variants, including cough, fatigue, headache and muscle pains. A loss of taste and smell is becoming less common.

Illness seems to be less severe, and hospitalizations and deaths remained somewhat steady since the omicron wave. Experts said that may be a result of Americans’ hybrid immunity from vaccination and previous infection.

How deadly is COVID-19?

Dowdy said transmission may be higher than at any other point in the pandemic – except during the winter’s omicron wave – but rates of hospitalizations and deaths have remained comparable with last summer.

Researchers at the National Cancer Institute found COVID-19 was the third leading cause of death in the U.S. from March 2020 to October 2021, according to an analysis of national death certificate data published this week in JAMA Internal Medicine, accounting for about 350,000 deaths.

At the height of this 20-month period in January 2021, the U.S. reported more than 4,000 deaths a day. The country now reports 200 to 400 deaths a day, according to Johns Hopkins and CDC data.

What will the pandemic look like this fall?

Some experts expect another increase in COVID-19 cases, hospitalizations and deaths in the fall, but Dowdy said case rates could look similar to what they are now.

“It seems like right now we’re at a high hum,” he said. “In the past, what has caused waves to subside has been our immunity to the virus, so I think it’s possible that our immunity will have a downward effect,” or keep cases down.

Aubree Gordon, associate professor at the University of Michigan School of Public Health, says the worst of COVID-19 may finally be behind us, barring the emergence of any new variants.

Experts say there have been no signs of a new variant. A study published in Nature this week found wastewater-based surveillance can detect emerging variants of concern up to two weeks earlier than clinical sequencing.

“Hopefully we will see that severity (of disease) continue to decrease and the rate of infections and number of cases will come down as well,” Gordon said. “We’re at the point in the U.S. where it is quite likely that the worst is over.”

Follow Adrianna Rodriguez on Twitter: @AdriannaUSAT.

Health and patient safety coverage at USA TODAY is made possible in part by a grant from the Masimo Foundation for Ethics, Innovation and Competition in Healthcare. The Masimo Foundation does not provide editorial input.

Undercounted Covid-19 cases leave US with a blind spot as BA.5 ...

CNN —

Official Covid-19 case metrics severely undercount the true number of infections, leaving the United States with a critical blind spot as the most transmissible coronavirus variant yet takes hold.

The Omicron offshoot BA.5 became the dominant variant in the US last week, according to data from the US Centers for Disease Control and Prevention, and the subvariant carries key mutations that help it escape antibodies generated by vaccines and prior infection, aiding its rapid spread.

With that will come “escalating numbers of cases and more hospitalizations,” Dr. Eric Topol, a cardiologist and professor of molecular medicine at Scripps Research, said on CNNi Monday. “One good thing is it doesn’t appear to be accompanied by the ICU admissions and the deaths as previous variants, but this is definitely concerning.”

But to look at official case counts, it’s hard to tell.

The share of cases that are officially reported is at an “all-time low,” said Dr. Michael Mina, an epidemiologist and chief science officer at telehealth company eMed. “There’s no doubt about that.”

Covid-19 cases have been undercounted to some degree throughout the pandemic for reasons including a lack of available tests at some points and asymptomatic cases that may have been missed. But as people increasingly rely on rapid at-home tests – and as attitudes toward the pandemic shift overall – the US hasn’t landed on a reliable way to track transmission levels.

An estimate from the Institute for Health Metrics, a research center at the University of Washington, suggests that actual infection numbers in the first week of July have been about seven times higher than reported cases – which have averaged about 107,000 each day over the past two weeks, according to data from Johns Hopkins University.

Before the CDC lifted the requirement for international travelers to test before coming into the country last month, Mina said, it was an “amazing opportunity” to monitor the state of Covid-19 across the US among a group of mostly asymptomatic people. About 5% of travelers were testing positive throughout the month of May, which he says probably translates to at least 1 million new infections every day in the broader US population – 10 times higher than the official count.

Now that BA.5 is here, “we know that there is going to be a wave in the fall – there’s almost no doubt about that – if not before. So you just have to be really cognitive that that is what might happen,” Mina said.

But with so many variables at play, it doesn’t necessarily make sense to compare the current state of things to other points in the pandemic.

“We really don’t have a good sense of what the baseline is,” said Dr. Marcus Plescia, chief medical officer at the Association of State and Territorial Health Officials. “To say ‘here’s where we are, at this time in 2022, compared to 2021’ – that’s not a fair comparison.”

To assess your individual risk of Covid-19 as a new variant takes hold, a personal accounting of cases among friends and family may be a better gauge than official data, experts say.

“People are asking one another, they’re sharing stories, and that’s probably not a bad source of evidence,” said Baruch Fischhoff, a professor at Carnegie Mellon University and founding chair of the US Food and Drug Association’s Risk Communication Advisory Committee.

Our social networks have probably stayed more consistent than national surveillance systems, he said, and “if more people that you hear about in your circle are getting the disease now than were getting it in the past, and the size of your circle is about the same, then presumably there’s much more disease now than there was before.”

Severe outcomes don’t tell the whole story

At White House Covid-19 Response Team briefings – the most recent of which was held more than two weeks ago – CDC Director Dr. Rochelle Walensky has presented case trends without referencing these important caveats to the data.

Months ago, the CDC shifted away from Covid-19 transmission levels that categorized risk based on case counts and test positivity rates to focus on Covid-19 Community Levels that rely more heavily on metrics related to hospitalizations.

During this winter’s Omicron surge, hospitalizations and deaths didn’t follow the same steep trend line as cases – an important shift from earlier waves of the pandemic.

But the fact that severe outcomes are still happening at all is enough reason to keep paying attention to cases, experts say.

“If we ever got to a state where people were getting infected but it wasn’t causing any severe illness anymore – maybe it’s a new variant that is much less severe, or it wasn’t causing long Covid – if there were no really significant adverse health outcomes, then we would no longer care as much about cases,” said Jason Salemi, an epidemiologist and associate professor at the University of South Florida.

“But let me be clear, we’re not there yet.”

There’s no evidence that BA.5 causes more severe disease, but studies have shown BA.5 can evade antibodies from vaccination or previous infection – even from another Omicron subvariant. Vaccines are still expected to provide protection against severe disease, and for fall, vaccine makers are developing updated booster shots that incorporate Omicron BA.4 and BA.5 strains.

There are treatments available, such the antiviral pill Paxlovid, that sharply reduce risk of death or severe disease. And high-quality masks, ventilation, physical distancing and quarantine and isolation can still help reduce spread from any variant, including BA.5.

But currently, more than 5,000 people are being admitted to the hospital with Covid-19 each day, CDC data shows, and more than 300 are dying each day, according to JHU data.

Focusing on these “lagging indicators” costs “meaningful time in which to start to curb people’s behavior and prevent a lot of morbidity and mortality,” Salemi said.

If 1 in 5 Covid-19 infections results in long Covid and true infections are seven times higher than reported, the number of people with long Covid could be growing by 100,000 each day.

Working around blind spots

For now, the US is in a “sustained management phase,” with continued efforts to keep things under control compared with “what was much more of a reactive, emergent – and emerging – approach of the past,” Plescia said.

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But the federal government recently reallocated resources away from testing because Congress did not approve additional Covid funds, a move that Mina says will leave the US “pretty blind as we move into the fall.”

Some surveillance programs are ongoing, such as wastewater monitoring that tracks the amount of virus present in sewage. But he says they’re “minimal,” and “generally, they’re not really not giving us a good picture of what’s really happening across the United States.”

“We kind of just floated through this major outbreak,” Mina said, referring to previously dominant Omicron subvariants. “But we should not let our guard down, I would say, because with BA.5, I expect it will be a very different story.”