However, vaccination against Covid-19 is expected to provide significant protection against severe disease, and vaccine manufacturers are working on updated vaccines that may elicit a stronger immune response against the variants.
“We observed a 3-fold decrease in the titers of neutralizing antibodies caused by vaccination and infection against BA4 and BA5 compared to BA1 and BA2, which are already significantly lower than the original versions of COVID-19”, Dr. Dan Baruch, author of the article 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 sub-variants of Omicron are likely to lead to spikes in infections in populations with high levels of immunity to the vaccine, as well as innate immunity to BA1 and BA2,” Baruch wrote. “However, the vaccine’s immunity is still likely to provide significant protection against severe disease with BA4 and BA5.”
The newly published findings reflect individual studies by scientists at Columbia University.
They recently found that BA.4 and BA.5 viruses were more likely to escape antibodies from the blood of fully vaccinated and boosted adults than other Omicron sub-variants, increasing the risk of Covid-19 infections that are the vaccine.
The authors of this separate study claim that their results show a higher risk of re-infection, even in people who have some previous immunity to the virus. The US Centers for Disease Control and Prevention estimates that 94.7% of the US population aged 16 and over have antibodies to the coronavirus that causes Covid-19 through vaccination, infection or both. BA.4 and BA.5 caused approximately 35% of new Covid-19 infections in the United States last week, up from 29% the previous week, according to data shared by the U.S. Centers for Disease Control and Prevention on Tuesday.
BA.4 and BA.5 are the fastest-spreading variants reported so far and are expected to dominate Covid-19 transmission in the United States, the United Kingdom and the rest of Europe over the next few weeks, according to the European Center for Prevention and Control. disease control.
“COVID-19 still has the ability to mutate further”
In a New England Journal of Medicine article, among 27 study participants who were 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 higher. -low response from the original coronavirus.
Neutralizing antibody levels were lower by a factor of 6.4 compared to BA.1; with a coefficient of 7 relative to BA.2; with a coefficient of 14.1 against BA.2.12.1 and with a coefficient of 21 against BA.4 or BA.5, the researchers described.
Among 27 participants who had previously been infected with subvariants BA.1 or BA.2 on average 29 days earlier, the researchers found similar results.
In those with a previous infection – most of whom have also been vaccinated – the researchers described levels of neutralizing antibodies that were lower by a factor of 6.4 against BA.1; with a coefficient of 5.8 relative to BA.2; with a coefficient of 9,6 against BA.2.12.1 and with a coefficient of 18,7 against BA.4 or BA.5.
More research is needed to determine exactly what levels of neutralizing antibodies mean for vaccine efficacy and whether such findings will occur among a larger group of participants.
“Our data suggest that COVID-19 still has the ability to mutate further, leading to increased transmissibility and increased antibody release,” Baruch wrote in an email. “As pandemic restrictions are removed, it is important to remain vigilant and continue to explore new options and sub-options as they arise.
A separate study published in the journal Nature last week found that Omicron may develop mutations to evade immunity caused by previous BA.1 infection, suggesting that boosters of BA.1-based vaccines may not achieve broad-spectrum protection against new Omicron sub-variants such as 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 need to be aware that they can get sick again, even before they have Covid-19.
“I think I’m a little worried about people who have had this, maybe recently have a false sense of security with BA.4 and BA.5 on the rise, because we’ve seen some cases of re-infection and I’ve seen some cases of re-infection with people who have had a BA.2 option in the last few months, ”he said.
Some vaccine manufacturers are developing variant-specific vaccines to improve antibody responses against coronavirus variants and subvariants that cause concern.
“Re-infections will be quite inevitable until we have vaccines or widespread mandates to prevent a resurgence of cases. But the good news is that we are in a much better place than we were without the vaccines,” said Pavitra Roychoudhuri. an instructor in acting in the Department of Laboratory Medicine and Pathology at the University of Washington, who did not participate in the New England Journal of Medicine article.
“There is so much of this virus that it seems inevitable,” she said of Covid-19 infections. “We hope that the protections we have will lead to a mostly mild infection.”
Efforts are being made to update Covid-19 vaccines
Moderna’s bivalent amplifier of the Covid-19 vaccine, called mRNA-1273.214, elicited a “powerful” immune response against Omicron sub-variants BA.4 and BA.5, the company said Wednesday.
This candidate for the bivalent booster vaccine contains components from both the original Moderna Covid-19 vaccine and the Omicron-targeted vaccine. The company said it was working to fill out regulatory applications in the coming weeks with a request to update the composition of its booster vaccine to be mRNA-1273.214.
“In the face of the ongoing evolution of SARS-CoV-2, we are very encouraged that mRNA-1273.214, our leading candidate for the autumn booster, has shown high neutralizing titers against sub-options BA.4 and BA.5, which pose a new threat to global public health, “said Stefan Bansel, CEO of Moderna, in a statement Wednesday. SARS-CoV-2 is the coronavirus that causes Covid-19.
“We will provide this data to regulators urgently and prepare to provide our next generation bivalent booster from August, before the potential increase in SARS-CoV-2 infections due to Omicron sub-variants in early autumn,” Bansel said.
The U.S. Food and Drug Administration’s Advisory Committee on Vaccines and Related Organic Products will meet next week to discuss the composition of Covid-19 vaccines, which could be used as boosters this fall.
Data released by Moderna on Wednesday, not published in a peer-reviewed journal, show that one month after administering a 50-microgram dose of mRNA-1273.214 to people who have been vaccinated and boosted, the vaccine has produced “powerful” neutralizing antibodies against BA.4 and BA.5, increasing levels 5.4-fold in all participants, regardless of whether they had a previous Covid-19 infection and 6.3-fold in the subgroup of those without a history of previous infection. These levels of neutralizing antibodies were about 3 times lower than previously reported neutralizing levels against BA.1, Moderna said.
These findings complement data published earlier this month by Moderna, showing that a dose of 50 micrograms of the bivalent booster generated a stronger response to antibodies to Omicron than the original Moderna vaccine.
Moderna’s data suggest that “the bivalent booster may provide greater protection against BA.4 and BA.5 omicron strains than re-administration of the original vaccine to increase public protection. Although the information is based on antibody levels, The companies commented that similar levels of antibodies protected against clinical disease caused by other strains was the first hypothesis of an emerging “immune correlate” of protection, although we hope that this ongoing study also assesses the extent of clinical disease. Antibody Responses, “Penny Ward, an independent pharmacist and visiting professor of pharmaceutical medicine at King’s College London, said in a statement issued by the UK-based Science Media Center on Wednesday. She was not involved in Moderna’s work.
“It has previously been reported that the bivalent vaccine is well tolerated with temporary ‘reactogenic’ effects similar to those after monovalent booster injection, so we can expect this new mixed vaccine to be well tolerated,” said Ward. “As we move into the fall with omicron variants dominating the covid infection landscape, it certainly makes sense to consider using this new bivalent vaccine, if available.
CNN’s Brenda Goodman contributed to this report.
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