Advisers to the U.S. Food and Drug Administration on Thursday unanimously voted in favor of targeting the same coronavirus strain for initial COVID-19 vaccine doses and boosters going forward, but some expressed skepticism about whether all Americans need to receive the shots annually.
The agency is trying to simplify its COVID-19 vaccine policy as it considers whether to recommend Americans get an annual booster shot for the virus. But several members of the expert advisory group asked for more robust data on benefits of annual shots for younger, healthier people.
"We're in a very different place. We have a lot of population immunity," said Hayley Gans, professor of pediatrics at Stanford University Medical Center. "Now that people are immune, how long does that last?"
Vaccine makers Pfizer Inc with partner BioNTech SE and Moderna Inc introduced late last year updated versions of their COVID vaccines tailored to target Omicron variants as well as the original coronavirus. In the United States, those were used only as booster shots.
The FDA advisory group unanimously backed using those shots for the primary series for those who have yet to be vaccinated against COVID-19 as well.
Frequently Asked Questions
A vaccine works by mimicking a natural infection. A vaccine not only induces immune response to protect people from any future COVID-19 infection, but also helps quickly build herd immunity to put an end to the pandemic. Herd immunity occurs when a sufficient percentage of a population becomes immune to a disease, making the spread of disease from person to person unlikely. The good news is that SARS-CoV-2 virus has been fairly stable, which increases the viability of a vaccine.
There are broadly four types of vaccine — one, a vaccine based on the whole virus (this could be either inactivated, or an attenuated [weakened] virus vaccine); two, a non-replicating viral vector vaccine that uses a benign virus as vector that carries the antigen of SARS-CoV; three, nucleic-acid vaccines that have genetic material like DNA and RNA of antigens like spike protein given to a person, helping human cells decode genetic material and produce the vaccine; and four, protein subunit vaccine wherein the recombinant proteins of SARS-COV-2 along with an adjuvant (booster) is given as a vaccine.
Vaccine development is a long, complex process. Unlike drugs that are given to people with a diseased, vaccines are given to healthy people and also vulnerable sections such as children, pregnant women and the elderly. So rigorous tests are compulsory. History says that the fastest time it took to develop a vaccine is five years, but it usually takes double or sometimes triple that time.
The FDA said it envisioned holding a meeting later in the year to determine the composition of shots for the fall, although some vaccine makers might be able to produce updated shots more quickly.
Pfizer/BioNTech and Moderna were able to produce the currently available messenger RNA boosters in about three months last year, but Novavax Inc said on Thursday it would require six months to make a new version of its protein-based COVID-19 vaccine designed to match circulating coronavirus variants.
FDA would consider an earlier timeline for vaccines like Novavax's following the company's manufacturing assessment, Peter Marks, director of the agency's Center for Biologics Evaluation & Research, said.
Health officials in the Biden administration have suggested that annual, updated COVID-19 booster shots could provide a high level of protection against severe disease.