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Covid: Omicron subvariants BA.4 and BA.5 escape antibodies from vaccination and prior infection, studies suggest

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However, Covid-19 vaccination is still expected to provide substantial protection against severe disease, and vaccine makers are working on updated shots that might elicit a stronger immune response against the variants.

“We observed 3-fold reductions of neutralizing antibody titers induced by vaccination and infection against BA4 and BA5 compared with BA1 and BA2, which are already substantially lower than the original COVID-19 variants,” Dr. Dan Barouch, an author of the paper and director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center in Boston, wrote in an email to CNN.

“Our data suggest that these new Omicron subvariants will likely be able to lead to surges of infections in populations with high levels of vaccine immunity as well as natural BA1 and BA2 immunity,” Barouch wrote. “However, it is likely that vaccine immunity will still provide substantial protection against severe disease with BA4 and BA5.”

The newly published findings echo separate research by scientists at Columbia University.

They recently found that the BA.4 and BA.5 viruses were more likely to escape antibodies from the blood of fully vaccinated and boosted adults compared with other Omicron subvariants, raising the risk of vaccine-breakthrough Covid-19 infections.

The authors of that separate study say their results point to a higher risk for reinfection, even in people who have some prior immunity against the virus. The US Centers for Disease Control and Prevention estimates 94.7% of the US population ages 16 and older have antibodies against the coronavirus that causes Covid-19 through vaccination, infection, or both.
BA.4 and BA.5 caused an estimated 35% of new Covid-19 infections in the United States last week, up from 29% the week before, according to data shared by the US Centers for Disease Control and Prevention on Tuesday.

BA.4 and BA.5 are the fastest spreading variants reported to date, and they are expected to dominate Covid-19 transmission in the United States, United Kingdom and the rest of Europe within the next few weeks, according to the European Centre for Disease Prevention and Control.

‘COVID-19 still has the capacity to mutate further’

In the New England Journal of Medicine paper, among 27 research participants who had been vaccinated and boosted with the Pfizer/BioNTech coronavirus vaccine, the researchers found that two weeks after the booster dose, levels of neutralizing antibodies against Omicron subvariants were much lower than the response against the original coronavirus.

The neutralizing antibody levels were lower by a factor of 6.4 against BA.1; by a factor of 7 against BA.2; by a factor of 14.1 against BA.2.12.1 and by a factor of 21 against BA.4 or BA.5, the researchers described.

Among 27 participants who had previously been infected with the BA.1 or BA.2 subvariants a median of 29 days earlier, the researchers found similar results.

In those with previous infection — most of whom also had been vaccinated — the researchers described neutralizing antibody levels that were lower by a factor of 6.4 against BA.1; by a factor of 5.8 against BA.2; by a factor of 9.6 against BA.2.12.1 and by a factor of 18.7 against BA.4 or BA.5.

More research is needed to determine what exactly the neutralizing antibody levels mean for vaccine effectiveness and whether similar findings would emerge among a larger group of participants.

“Our data suggest that COVID-19 still has the capacity to mutate further, resulting in increased transmissibility and increased antibody escape,” Barouch wrote in the email. “As pandemic restrictions are lifted, it is important that we remain vigilant and keep studying new variants and subvariants as they emerge.”

A separate study, published in the journal Nature last week, found that Omicron may evolve mutations to evade the immunity elicited by having a previous BA.1 infection, which suggests that vaccine boosters based on BA.1 may not achieve broad-spectrum protection against new Omicron subvariants like BA.4 and BA.5.

As for what all this means in the real world, Dr. Wesley Long, an experimental pathologist at Houston Methodist Hospital, told CNN that people should be aware that they could get sick again, even if they’ve had Covid-19 before.

“I think I’m a little bit worried about people who’ve had it maybe recently having a false sense of security with BA.4 and BA.5 on the increase, because we have seen some cases of reinfection and I have seen some cases of reinfection with people who had a BA.2 variant in the last few months,” he said.

Some vaccine makers have been developing variant-specific vaccines to improve the antibody responses against coronavirus variants and subvariants of concern.

“Reinfections are going to be pretty inevitable until we have vaccines or widespread mandates that are going to prevent cases rising again. But the good news is that we are in, I think, a much better spot than we were without the vaccines,” said Pavitra Roychoudhury, an acting instructor at the University of Washington’s Department of Laboratory Medicine and Pathology, who was not involved in the New England Journal of Medicine paper.

“There’s so much of this virus out there that it seems inevitable,” she said about Covid-19 infections. “Hopefully the protections that we have in place are going to lead to mostly mild infection.”

Efforts underway to update Covid-19 vaccines

Moderna’s bivalent Covid-19 vaccine booster, named mRNA-1273.214, elicited a “potent” immune responses against the Omicron subvariants BA.4 and BA.5, the company said Wednesday.

This bivalent booster vaccine candidate contains components of both Moderna’s original Covid-19 vaccine and a vaccine that targets the Omicron variant. The company said it is working to complete regulatory submissions in the coming weeks requesting to update the composition of its booster vaccine to be mRNA-1273.214.

“In the face of SARS-CoV-2’s continued evolution, we are very encouraged that mRNA-1273.214, our lead booster candidate for the fall, has shown high neutralizing titers against the BA.4 and BA.5 subvariants, which represent an emergent threat to global public health,” Stéphane Bancel, chief executive officer of Moderna, said in Wednesday’s announcement. SARS-CoV-2 is the coronavirus that causes Covid-19.

“We will submit these data to regulators urgently and are preparing to supply our next generation bivalent booster starting in August, ahead of a potential rise in SARS-CoV-2 infections due to Omicron subvariants in the early fall,” Bancel said.

The US Food and Drug Administration’s Vaccines and Related Biological Products Advisory Committee is meeting next week to discuss the composition of Covid-19 vaccines that could be used as boosters this fall.

The data that Moderna released Wednesday, which has not been published in a peer-reviewed journal, showed that one month after a 50-microgram dose of the mRNA-1273.214 vaccine was administered in people who had been vaccinated and boosted, the vaccine elicited “potent” neutralizing antibody responses against BA.4 and BA.5, boosting levels 5.4-fold in all participants regardless of whether they had a prior Covid-19 infection and by 6.3-fold in the subset of those with no history of prior infection. These levels of neutralizing antibodies were about 3-fold lower than previously reported neutralizing levels against BA.1, Moderna said.

These findings add to the data that Moderna previously released earlier this month, showing that the 50-microgram dose of the bivalent booster generated a stronger antibody response against Omicron than the original Moderna vaccine.

Moderna’s data suggest that “the bivalent booster might confer greater protection against the BA.4 and BA.5 omicron strains than readministering the original vaccine to increase protection across the population. Although the information is based on antibody levels, the companies comment that similar levels of antibody protected against clinical illness caused by other strains is the first suggestion of an emerging ‘immune correlate’ of protection, although it is hoped that this ongoing study is also assessing rates of clinical illness as well as antibody responses,” Penny Ward, an independent pharmaceutical physician and visiting professor in pharmaceutical medicine at King’s College London, said in a statement released by the UK-based Science Media Centre on Wednesday. She was not involved in Moderna’s work.

“It has been reported previously that the bivalent vaccine is well tolerated with temporary ‘reactogenic’ effects similar to those following the univalent booster injection so we can anticipate that this new mixed vaccine should be well tolerated,” Ward said in part. “As we head towards the autumn with omicron variants dominating the covid infection landscape, it certainly makes sense to consider use of this new bivalent vaccine, if available.”

CNN’s Brenda Goodman contributed to this report.

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The Common Places BA.2 And Other Omicron Subvariants Are Spreading

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Earlier in the pandemic, contact tracing data showed us where COVID-19 was predominantly spreading. Unfortunately, because our contact tracing efforts have slowed down, we don’t have as clear of a picture regarding where people are mostly likely to contract omicron and its subvariants.

What we do know is that, while the virus has evolved to be much more transmissible than previous variants, the way COVID-19 spreads hasn’t changed. “Nothing has changed in terms of how any individual right now, regardless of their day-to-day activity, can pick this virus up,” Mark Cameron, infectious disease researcher at Case Western Reserve University, told HuffPost.

Because of that, we can assume there are some hot spots for BA.2 and other omicron subvariants compared to others. Here are common places where COVID-19 still spreads, according to experts:

Crowded, indoor events

By now, we’ve all heard it a million times. COVID-19 spreads in crowded, indoor settings — think: gyms, restaurants, concerts, bars and the like.

Cameron said there’s no shortage of anecdotes about how the virus is spreading at such events. Massive outbreaks have recently been recorded after Phish’s four-night concert run, the White House Correspondents’ Dinner, and the annual Washington Gridiron Club dinner, as well as on cruises and after high school proms.

In crowded, poorly ventilated indoor settings, aerosols containing the virus can spread in the air and easily be inhaled by many.

“Similar to other COVID variants, BA.2 spreads more easily in crowded, indoor locations with limited ventilation,” said Bernadette Boden-Albala, director and founding dean of the Program in Public Health at the University of California, Irvine.

Households

COVID-19 is also known to spread easily between family members — and roommates — who live together. Research published by the Centers for Disease Control and Prevention in February shows that COVID-19 now has a household transmission rate of about 53%. Transmission is even more likely to occur when members of the same household are unvaccinated along with those who don’t wear a mask or isolate.

“The ability to transmit from one person to another in close quarters, that will still happen. Nothing has changed in terms of how we can catch this very infectious airborne virus when we are in close proximity to someone else,” Cameron said.

Boden-Albala said household spread is especially prominent in apartment living and multi-family homes, which reaffirms that COVID-19 ― and all its strains ― can be a disease of disparities.

Even though the variants have changed, how COVID spreads largely remains the same.

Nursing homes and congregate living facilities

Since the start of the pandemic, COVID-19 has been shown to rip through senior care facilities. While recent data from the CDC shows that boosters significantly help nursing home residents avoid severe outcomes, nursing homes and other congregate living facilities are still prone to major outbreaks.

Seventeen long-term care homes in Winnipeg, Canada, reported outbreaks last week. A women’s prison in Vermont experienced an outbreak in late April, as have a handful of long-term care facilities in the state.

“Those are, since the start and still are, the hotbeds of outbreaks,” Cameron said.

Close contacts indoors

Andrew Noymer, an epidemiologist and demographer who studies infectious diseases at University of California, Irvine, said the main takeaway is that COVID-19 spreads indoors. “Anywhere you’re indoors, that’s where it’s spreading — anywhere and everywhere,” Noymer said.

Boden-Albala noted that BA.2 is spreading in places that are the usual suspects: “settings like bars and restaurants where attendees may share food and beverages or wear their masks intermittently — if at all.”

Whether you have dinner at a friend’s house, go over to a relative’s for game night, take a taxi, go into an office or go out to eat, if you are indoors, there is a risk you could catch COVID-19. While planes are typically less risky due to their powerful air filtration systems, people can still catch COVID-19 while flying if they are seated near someone who is infected. Despite the fact that masking is no longer required on planes, Noymer continues to recommend wearing an N95 mask on a plane.

The risk of being exposed to COVID-19 may be less now than it was in January, when the country experienced a massive surge, but it is still notable since the latest variants are that much more contagious.

“These new omicron variants are fit and they’re easily transmittable,” Cameron said.

Experts are still learning about COVID-19. The information in this story is what was known or available as of publication, but guidance can change as scientists discover more about the virus. Please check the Centers for Disease Control and Prevention for the most updated recommendations.

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Health

The Common Places BA.2 And Other Omicron Subvariants Are Spreading

Leave a comment

Earlier in the pandemic, contact tracing data showed us where COVID-19 was predominantly spreading. Unfortunately, because our contact tracing efforts have slowed down, we don’t have as clear of a picture regarding where people are mostly likely to contract omicron and its subvariants.

What we do know is that, while the virus has evolved to be much more transmissible than previous variants, the way COVID-19 spreads hasn’t changed. “Nothing has changed in terms of how any individual right now, regardless of their day-to-day activity, can pick this virus up,” Mark Cameron, infectious disease researcher at Case Western Reserve University, told HuffPost.

Because of that, we can assume there are some hot spots for BA.2 and other omicron subvariants compared to others. Here are common places where COVID-19 still spreads, according to experts:

Crowded, indoor events

By now, we’ve all heard it a million times. COVID-19 spreads in crowded, indoor settings — think: gyms, restaurants, concerts, bars and the like.

Cameron said there’s no shortage of anecdotes about how the virus is spreading at such events. Massive outbreaks have recently been recorded after Phish’s four-night concert run, the White House Correspondents’ Dinner, and the annual Washington Gridiron Club dinner, as well as on cruises and after high school proms.

In crowded, poorly ventilated indoor settings, aerosols containing the virus can spread in the air and easily be inhaled by many.

“Similar to other COVID variants, BA.2 spreads more easily in crowded, indoor locations with limited ventilation,” said Bernadette Boden-Albala, director and founding dean of the Program in Public Health at the University of California, Irvine.

Households

COVID-19 is also known to spread easily between family members — and roommates — who live together. Research published by the Centers for Disease Control and Prevention in February shows that COVID-19 now has a household transmission rate of about 53%. Transmission is even more likely to occur when members of the same household are unvaccinated along with those who don’t wear a mask or isolate.

“The ability to transmit from one person to another in close quarters, that will still happen. Nothing has changed in terms of how we can catch this very infectious airborne virus when we are in close proximity to someone else,” Cameron said.

Boden-Albala said household spread is especially prominent in apartment living and multi-family homes, which reaffirms that COVID-19 ― and all its strains ― can be a disease of disparities.

Even though the variants have changed, how COVID spreads largely remains the same. (Photo: AzmanL via Getty Images)

Even though the variants have changed, how COVID spreads largely remains the same. (Photo: AzmanL via Getty Images)

Nursing homes and congregate living facilities

Since the start of the pandemic, COVID-19 has been shown to rip through senior care facilities. While recent data from the CDC shows that boosters significantly help nursing home residents avoid severe outcomes, nursing homes and other congregate living facilities are still prone to major outbreaks.

Seventeen long-term care homes in Winnipeg, Canada, reported outbreaks last week. A women’s prison in Vermont experienced an outbreak in late April, as have a handful of long-term care facilities in the state.

“Those are, since the start and still are, thehotbeds of outbreaks,” Cameron said.

Close contacts indoors

Andrew Noymer, an epidemiologist and demographer who studies infectious diseases at University of California, Irvine, said the main takeaway is that COVID-19 spreads indoors. “Anywhere you’re indoors, that’s where it’s spreading — anywhere and everywhere,” Noymer said.

Boden-Albala noted that BA.2 is spreading in places that are the usual suspects: “settings like bars and restaurants where attendees may share food and beverages or wear their masks intermittently — if at all.”

Whether you have dinner at a friend’s house, go over to a relative’s for game night, take a taxi, go into an office or go out to eat, if you are indoors, there is a risk you could catch COVID-19. While planes are typically less risky due to their powerful air filtration systems, people can still catch COVID-19 while flying if they are seated near someone who is infected. Despite the fact that masking is no longer required on planes, Noymer continues to recommend wearing an N95 mask on a plane.

The risk of being exposed to COVID-19 may be less now than it was in January, when the country experienced a massive surge, but it is still notable since the latest variants are that much more contagious.

“These new omicron variants are fit and they’re easily transmittable,” Cameron said.

Experts are still learning about COVID-19. The information in this story is what was known or available as of publication, but guidance can change as scientists discover more about the virus. Please check the Centers for Disease Control and Prevention for the most updated recommendations.

This article originally appeared on HuffPost and has been updated.

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Three new Covid Omicron subvariants detected in Australia | Health

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Three new Omicron subvariants have reached Australia and health authorities say people who contract the virus should wait three months before getting their next Covid-19 vaccination.

Assoc Prof Stuart Turville from the University of New South Wales’ Kirby Institute says Omicron subvariants BA.2.12.1, BA.4 and BA.5 have been detected in the country.

Authorities are warning this winter season is likely to see a spike in Covid-19 cases and flu as restrictions which have suppressed the circulation of both viruses are phased out.

The latest advice from the Australian Technical Advisory Group on Immunisation recommends people wait three months after a confirmed Covid-19 infection and then receive their next vaccine dose as soon as possible.

The advice, issued last week, applies to all people and for all Covid-19 vaccines.

Turville said the severity and transmissibility of the new Omicron subvariants had yet to be determined.

The arrival of Omicron BA.1 and BA.2 were marked by their ability to significantly evade a previous antibody response through past infection and/or vaccination, but the impact was less severe.

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The new subvariants BA.4, BA.5 and BA2.12.1 are likely to displace BA.1 and BA.2 in Australia.

“We will need to study this over time to see if their advantage is one of “fitness/transmissibility” and/or their ability to be more slippery to existing antibodies,” Turville said. “As with all variants, the key parameter to watch is disease severity and this data takes time to accumulate.

“There is still a lot about this virus that is unknown and there are many paths it has the potential to take.”

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Omicron subvariants: New, fitter Covid-19 viruses begin to drive their own waves

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Cases are trending up in most states and have increased by more than 50% compared with the previous week in Washington, Mississippi, Georgia, Maine, Hawaii, South Dakota, Nevada and Montana. In New York, more than a quarter of the state’s population is in a county with a “high” Covid-19 community level, where the US Centers for Disease Control and Prevention recommends indoor masking.

Average daily hospitalizations are up about 10% since last week, according to data collected by the US Department of Health and Human Services.

The culprit this time appears to be a spinoff of Omicron’s BA.2 subvariant called BA.2.12.1, which was first flagged by New York state health officials in April.

BA.2.12.1, which is growing about 25% faster than its parent virus, BA.2, accounts for nearly 37% all Covid-19 cases across the US, according to new estimates from the CDC.

BA.2 caused an estimated 62% of all Covid-19 cases last week, down from 70% the week before.

US, South Africa contend with faster new variants

BA.2.12.1 isn’t the only Omicron offshoot that scientists are watching.

After weeks of declines, South Africa saw its Covid-19 cases rise steeply in the past two weeks. Test positivity and hospitalizations have also popped up as scientists have watched two relatively new subvariants, BA.4 and BA.5, dominate transmission in that country. Taken together, they accounted for almost 60% of all new Covid-19 cases by the end of April, according to South Africa’s National Institute of Communicable Diseases.

These new Omicron subvariants are spreading around the globe. BA.4 sequences have been reported in 15 countries and 10 US states, while BA.5 has been picked up in 13 countries and five US states, according to the website Outbreak.info, which maintained by a coalition of academic research centers and is supported by funding from the National Institutes of Health.

Like BA.2.12.1, BA.4 and BA.5 have a growth advantage over BA.2.

Omicron subvariants escape immunity

A new preprint study, published ahead of peer review, is pointing to why BA.4 and BA.5 are gaining ground: They can escape antibodies generated by previous infections caused by the first Omicron virus, BA.1, the variant responsible for the huge wave of infections that hit many countries in December and January. They can also escape antibodies in people who’ve been vaccinated and had breakthrough BA.1 infections, though this happened to a lesser degree than seen in people who’ve only been infected.

Researchers in South Africa tested the ability of antibodies in blood to disable BA.4 and BA.5 viruses in a lab. In people who were unvaccinated but recently recovered from a BA.1 infection, they saw a more than seven-fold drop in the ability of their antibodies to neutralize BA.4 and BA.5 viruses. In people who’d been vaccinated but recently had a breakthrough infection caused by BA.1, the drops were smaller, about three-fold lower.

By way of comparison, the World Health Organization uses an eight-fold drop in neutralization as the threshold for the loss of protection that requires an update to seasonal influenza vaccines.

The study results led the researchers to write that “BA.4 and BA.5 have potential to result in a new infection wave,” making Covid-19 vaccinations and booster shots crucial to stopping the next wave.

“Our conclusions from this are, first, that Omicron by itself is not a great vaccine, right?” said Alex Sigal, a virologist at the Africa Health Research Institute who led the study. “Just because you were infected does not mean you have a lot of protection from what’s coming next.”

Dr. Eric Topol, a cardiologist who is the founder and director of the Scripps Research Translational Institute, praised the research, pointing out that this lab was also the first to characterize the first Omicron variant: “They’ve been first-rate all the way through the pandemic.”

He said that overall, the finding was not good news. Even people who recovered from a Covid-19 infection as recently as December or January can be reinfected by these new subvariants.

“That dropoff of immune escape or immune evasion was pronounced in people who were unvaccinated,” Topol said, pointing out that only about 1 in 3 people in South Africa have been vaccinated against Covid-19.

For those who are vaccinated, “those people are also not as bad, but they also have to face BA.4 and BA.5 with less solid neutralizing antibody response,” he said. “The mutations in BA.4 and BA.5 are playing out to be a challenge to our immune response.”

Only a few dozen sequences of these viruses have been reported in the US and Canada. Researchers say it’s just too early to know whether BA.4 or BA.5 will take off in the United States.

It wouldn’t be surprising if they do, said Andy Pekosz, a virologist and professor of molecular microbiology and immunology at Johns Hopkins University.

“We’ve seen this over and over again. As a variant becomes dominant in another country eventually ends up here in the US and spreading globally,” Pekosz said.

In the meantime, Topol said, we have our own sublineage to deal with: BA.2.12.1.

“It may simulate the problems of BA.4 and BA.5,” Topol said. “We don’t know yet because there’s no study like this one from the Sigal lab.”

Shared mutation

The BA.4 and BA.5 viruses and BA.2.12.1 have mutations at location 452 of their genomes. This region codes for a part of the viruses receptor binding domain — the part of the virus that docks onto a door on the outside of our cells. The Delta variant and some others have picked up mutations in this location. Researchers believe that changes there help the virus bind more tightly to our cells and hide from frontline immune defenders called antibodies that try to block the virus from invading our cells.

“That may make it transmit better perhaps between our cells as well,” Sigal said.

BA.4 and BA.5 also have changes at location 486, which is a bit of a head-scratcher because previous viruses that changed in this location didn’t do well. They fizzled out.

“Suddenly, this guy manages it. So we don’t know what that does,” Sigal said. “My suspicion is that’s a heavy escape mutation,” meaning it helps the virus hide from our immune system.

Scientists have begun work to try to better understand BA.2.12.1, which has been detected in 22 countries, though most of the sequences have come from the United States.

Pekosz said he has been growing copies of BA.2.12.1 in his lab and has recently shipped samples of the virus to other research groups for study. He said scientists have just started talking about experiments they want to do to try to answer two key questions: How quickly is it copying itself, and how well does it escape our immunity?

Before the SARS-CoV-2 virus, scientists thought coronaviruses didn’t change much. Pekosz said that, looking back, we didn’t know what we didn’t know.

As long as the virus continues to find hosts to infect, it will continue to evolve.

“This virus has shown that it mutated slowly, but when it started to pick up good mutations, they just kept coming and coming and coming,” he said.

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Reinfections with Omicron subvariants are rare, Danish study finds

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Test tube labelled “COVID-19 Omicron variant test positive” is seen in this illustration picture taken January 15, 2022. REUTERS/Dado Ruvic

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COPENHAGEN, Feb 22 (Reuters) – Getting infected twice with two different Omicron coronavirus subvariants is possible, but rarely happens, a Danish study has found.

In Denmark, a more infectious sublineage of the Omicron coronavirus variant known as BA.2 has quickly dethroned the “original” BA.1 variant, which is the most common worldwide, but it has remained unclear whether a person could get infected by both variants.

A new study, led by researchers at Denmark’s top infectious disease authority, Statens Serum Institut (SSI), shows that people infected with BA.1 can get infected with BA.2 shortly afterwards, but that it is a rare occurrence.

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“We provide evidence that Omicron BA.2 reinfections are rare but can occur relatively shortly after a BA.1 infection,” the study authors said.

BA.1 and BA.2 differ by up to 40 mutations. While BA.2 accounts for more than 88% of cases in Denmark, cases have started to increase in the United Kingdom, South Africa and Norway.

The reinfections mostly affected young, unvaccinated individuals and only caused mild disease, none of which led to hospitalisations or deaths, the researchers added.

The study, which is not yet peer-reviewed, found 1,739 cases registered between Nov 21, 2021, and Feb 11 this year, where people had tested positive twice between 20 and 60 days apart.

In that period more than 1.8 million infections were registered in Denmark.

From a smaller sample group, the study found 47 instances of BA.2 reinfections shortly after a BA.1 infection. The researchers also detected less virus material at the second infection, suggesting some immunity was developed from the first infections.

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Reporting by Nikolaj Skydsgaard, Editing by William Maclean

Our Standards: The Thomson Reuters Trust Principles.

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