According to new data from researchers at the Beth Israel Deaconess Medical Center, part of the Harvard Medical School School.
However, vaccination against COVID-19 is still expected to provide significant protection against severe illness, and vaccine manufacturers are working on updated shots that could induce a stronger immune response. against variations.
According to new research published in the New England Journal of Medicine on Wednesday, neutralizing antibody levels to the BA.4 and BA.5 sub-variants are several times lower than that of the original coronavirus.
Dr Dan Barouch, author of the paper: “We observed a 3-fold decrease in neutralizing antibody titers induced by vaccination and infection for BA4 and BA5 compared with BA1 and BA2, which are already low significantly more than the original COVID-19 variants,” said Dr. Dan Barouch, author of the paper. and director of the Center for Virus and Vaccine Research at Beth Israel Deaconess Medical Center in Boston, wrote in an email to CNN.
“Our data suggest that these new sub-Omicron bacteria will potentially lead to increased infections in populations with high levels of vaccine immunity as well as BA1 immunity,” Barouch writes. and natural BA2. “However, it is likely that vaccine immunity still provides significant protection against severe disease with BA4 and BA5.”
The newly published findings reflect separate research by scientists at Columbia University.
They recently found that BA.4 and BA.5 viruses are more likely to escape antibodies from the blood of fully vaccinated and health-promoting adults than the Omicron subtype bacteria. other, increasing the risk of a breakthrough COVID-19 infection with a vaccine.
The authors of that separate study say that their results suggest a higher risk of reinfection, even in people who already have some prior immunity against the virus. The US Centers for Disease Control and Prevention estimates that 94.7% of the US population 16 years of age 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 previous week, according to data shared by the Centers for Disease Control and Prevention. United States on Tuesday.
BA.4 and BA.5 are the fastest-spreading variants reported to date, and they are projected to dominate COVID-19 transmission in the United States, United Kingdom, and the rest of Europe within the next five years. next few weeks, according to the European Center for Disease Prevention and Control.
‘COVID-19 still has the potential to mutate further’
In the New England Journal of Medicine article, of 27 study participants who received the Pfizer/BioNTech coronavirus vaccine booster and vaccination, researchers found that two weeks after the booster dose, levels neutralizing antibody levels against the Omicron subvariants were much lower than the response against the original coronavirus.
The level of neutralizing antibodies is by a factor of 6.4 lower than BA.1; by a factor of 7 compared to BA.2; by a factor of 14.1 versus BA.2.12.1 and a factor of 21 versus BA.4 or BA.5, the researchers describe.
Of the 27 participants who had previously been infected with the BA.1 or BA.2 subvariables for an average of 29 days prior, the researchers found similar results.
In people with previous infections – most of whom were also vaccinated – the researchers described lower levels of neutralizing antibodies by a factor 6.4 against BA.1; by a factor of 5.8 compared to BA.2; by a factor of 9.6 compared to BA.2.12.1 and by a factor of 18.7 compared to BA.4 or BA.5.
More research is needed to determine exactly what neutralizing antibody levels mean for vaccine effectiveness and whether similar findings emerge in a larger group of participants.
“Our data suggest that COVID-19 still has the potential to further mutate, leading to increased transmissibility and increased antibody escape,” Barouch wrote in an email. “As pandemic restrictions are lifted, it’s important that we stay alert and continue to study new variants and sub-variants as they emerge.”
A separate study, published in the journal Nature last week, found that Omicron can evolve mutations to eliminate immunity from previous BA.1 infections, which suggests that the drug BA.1-based vaccine boosters may not provide broad-spectrum protection against novel Omicron subvariables such as BA.4 and BA.5.
As for what all of 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 can get sick again. , even if they have had COVID-19 before.
“I think I’m a little worried that people who’ve had it may have recently had a false sense of security with BA.4 and BA.5 on the rise, because we’ve seen some reinfection and I’ve seen several reinfections with people with the BA.2 variant in the last few months,” he said.
Several vaccine manufacturers have been developing specific variant vaccines to improve antibody response against coronavirus variants and subvariants of concern.
“Revaccination is inevitable until we have a vaccine or widespread mandates that will prevent cases from rising again. But the good news is that we are in a much better position than we are. at a time when we didn’t have a vaccine.” Pavitra Roychoudhury, an acting instructor in the University of Washington Department of Laboratory Medicine and Pathology, who was not involved in the New England Journal of Medicine article.
“There are so many of these viruses out there that it just seems inevitable,” she said. “Hopefully the protective measures we’re putting in place will lead to mostly mild infections.”
Efforts are underway to update the Covid-19 vaccine
The company said on Wednesday it said Moderna’s bivalent COVID-19 vaccine, named mRNA-1273,214, produced a “strong” immune response against BA.4 subvariables. and Omicron’s BA.5.
This bivalent booster vaccine candidate contains components of both Moderna’s original COVID-19 vaccine and a vaccine targeting the Omicron variant. The company said it is working to complete regulatory submissions in the coming weeks to request that the booster vaccine’s composition be updated to mRNA-1273,214.
“Faced with the continued evolution of SARS-CoV-2, we strongly recommend that mRNA-1273,214, our top booster candidate for fall, has shown a high neutralizing titer compared with the sub-variables BA.4 and BA.5, representing the emerging Stéphane Bancel, chief executive officer of Moderna, said in Wednesday’s announcement. SARS-CoV-2 is the coronavirus that causes COVID-19.
“We are urgently submitting these data to regulators and are preparing to deliver our next-generation bivalent chemotherapy enhancer starting in August, ahead of the potential increase,” Bancel said. increased likelihood of SARS-CoV-2 infection due to Omicron subvariables in early autumn”.
The U.S. Food and Drug Administration’s Advisory Committee on Vaccines and Related Biological Products will meet next week to discuss the composition of a COVID-19 vaccine that could be used as a vaccine. boosters this fall.
Data that Moderna published on Wednesday, which has not been published in a peer-reviewed journal, shows that one month after a dose of 50 micrograms of vaccine mRNA-1273,214 was administered to people who had already been vaccinated. and booster, the vaccine appeared.” Strong inactivating antibody responses against BA.4 and BA.5, increased levels 5.4-fold in all participants regardless of whether they had pre-infected with COVID-19 and 6.3 times more in a small group of people with no history of previous infection.Moderna says the level of this neutralizing antibody is about 3 times lower than neutral previously reported for BA.1.
These findings add to data that Moderna previously published earlier this month, showing that a 50 microgram dose of the divalent enhancer induces a stronger antibody response against Omicron than the original Moderna vaccine. head.
Moderna data suggest that “the bivalent booster may provide better protection against Omicron strains BA.4 and BA.5 than using the parent vaccine to enhance protection against protection over the entire population.
Although the information is based on antibody levels, the companies comment that similar levels of antibodies are protective against clinical disease caused by other strains is the first suggestion of an ‘immunological correlation’. ‘ is emerging for protection, although it is hoped that this ongoing study is also evaluating Penny Ward, an independent pharmacologist and visiting professor of pharmacy at King’s College London. , said in a statement released by the UK-based Center for Science Communication on Wednesday, which said the clinical incidence as well as the response to the antibody. Works of Moderna.
“It has been previously reported that divalent vaccines are well tolerated with transient ‘reactive’ effects similar to those following a single booster dose, because so we can predict that this new mixed vaccine will be well tolerated,” said Ward. “As we head into the fall with omicron variants dominating the covid infection landscape, it will certainly be.” It makes sense to consider using this new dual-value vaccine, if available.”