Dr. Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, speaks in Washington on March 18, 2021. (Susan Walsh/Pool/Getty Images)
The Epoch Times
Two new studies that showed the updated COVID-19 boosters provoked an immune response similar to the one triggered by the old boosters will not have an effect on the U.S. Food and Drug Administration’s emergency use authorizations, a top regulator says.
Dr. Peter Marks, head of the FDA’s Center for Biologics Evaluation and Research, told The Epoch Times via email that the studies were based on “small numbers of individuals” and that data from larger studies are expected to be available soon.
“FDA continues to encourage eligible individuals to consider receiving an updated vaccine to help protect against the currently circulating COVID-19 variants and the wave of COVID-19 that appears to be coming,” he added.
The FDA in August granted emergency authorization to updated boosters from Moderna and Pfizer that target the BA.4 and BA.5 Omicron subvariants, despite no clinical data being available.
The agency said at the time that data from mice experiments and safety and effectiveness data from the old shots indicated the new boosters would provide better protection.
The old shots, which are still the only ones available as a primary series, targeted only the original Wuhan virus strain. That strain has not been around for nearly two years. Omicron emerged in the United States in late 2021.
In one of the new studies, researchers with Columbia University and the University of Michigan collected sera, or blood serum, from people who received three or four doses of the original vaccines and people who received a new booster as a fourth dose.
They found (pdf) that people who received an old booster had higher neutralizing antibody titers than those who received a new booster.
“The main finding is that we did not see broader immunity generated by the bivalent booster compared to the original monovalent booster,” Aubree Gordon, an associate professor at the University of Michigan’s School of Public Health and a co-author of one of the papers, told The Epoch Times via email.
Neutralizing antibodies are believed to protect against the COVID-19 virus.
In the other study (pdf), researchers at the Beth Israel Deaconess Medical Center in Massachusetts compared the immune responses of people who received an old booster to people who received a new booster.
They found the levels of tiers “were comparable” between the groups.
The first study did not list the number of people studied. The second examined 33 total people.
“Data from larger, well controlled studies that are not subject to the same limitation of these smaller studies are expected to be available in the near future,” Marks said.
“That said, it is important to note that even the data from these initial small studies indicate that the bivalent vaccines are generally at least as good or better as the original vaccines in generating an immune response, particularly to BA.4/BA.5 and other newer variants. Additionally, even modest improvements in vaccine response to the bivalent boosters could have important positive consequences on public health,” he added.
The efficacy results from trials run by Pfizer and Moderna are expected by the end of the year.
Interim results from about 80 people showed a “substantial increase” in antibodies against BA.4 and BA.5 a week after injection, Pfizer said in October. The company released no data in support of its statement. Moderna has only released results from a different booster, a Wuhan/BA.1 bivalent, that a number of other countries—but not the United States—has authorized.
Gordon agreed with Marks’s statement.
“We did not look at efficacy in our study, just neutralizing antibodies which we know do correlate with efficacy. We also know that prior boosters worked, particularly in helping to prevent severe disease. So, while our data do not support the bivalent booster as being better at generating a broad response, it did generate a strong response and people should get their bivalent booster,” she said.
The old boosters have been performing worse against Omicron and its subvariants, with the protection against both infection and severe illness quickly waning, according to federal data.
Dr. Vinay Prasad, a professor in the Department of Epidemiology and Biostatistics at the University of California, San Francisco, said that without clinical data, endpoints in trials are unlikely to be met.
Dr. Dan Barouch, the corresponding author for the other study, did not respond to a request for comment.
Just 7.3 percent of Americans aged 5 and older have received an updated booster as of Oct. 27.
Both groups of researchers suggested that immune imprinting, when an immune system is locked into a response to an old virus strain, may be a factor in the results of the studies.
“Our findings suggest that immune imprinting by prior antigenic exposure may pose a greater challenge than currently appreciated for inducing robust immunity to SARS-CoV-2 variants,” one group said. SARS-CoV-2 is the name of the virus that causes the COVID-19 disease.
“These findings may be indicative of immunological imprinting, although follow-up studies are needed to determine if the antibody responses will deviate in time, including the impact of a second bivalent booster,” the other said.