Scientists are divided over the US Food and Drug Administration’s (FDA) proposal to renew the COVID-19 vaccine once a year, similar to the agency’s approach to renewing the flu vaccine. At the FDA’s Vaccine Advisory Committee meeting on Jan. 26, some researchers said the plan would help simplify his country’s complex COVID-19 vaccination schedule, resulting in lower vaccination rates. argued that it could be increased.
But some were less certain about whether jabs should be renewed every fall in the United States, or whether healthy adults should be encouraged to receive COVID-19 jabs each year.Pennsylvania Angela Shen, a vaccine specialist at the Children’s Hospital of Philadelphia, said the proposal, which was announced Monday, “isn’t a bad idea conceptually.” But she wonders if the data support her one vaccine composition update per year, because SARS-CoV-2 produces new variants at a different rate than influenza. “Since COVID is not the flu, simply removing ‘flu’ and replacing it with ‘COVID’ in all documents may not work,” said Shen, a former member of the U.S. Centers for Disease Control and Prevention (CDC). increase. Advisory Committee on Immunization.
The timeline for updating influenza vaccination is based on well-documented seasonal patterns of emergence of new strains. The choice of strain for the northern hemisphere vaccine is based in part on which version spread widely during previous southern hemisphere winters. Its pattern is not as predictable as the flu.
“We understand the seasonality of influenza and know exactly when to vaccinate for optimal effectiveness,” said the former acting FDA chief scientist, now based in New York. said Luciana Borio, a global health expert at the city’s Council on Foreign Relations. But “she doesn’t know if people need to be vaccinated every year or less frequently to protect against severe COVID.”
Moreover, SARS-CoV-2 variants do not sweep the globe as uniformly as influenza strains, making it difficult to coordinate the composition of the COVID-19 jab globally. Bruce Guerin, a global health expert at the Rockefeller Foundation’s Pandemic Prevention Initiative in New York City, said at a conference that the annual renewal proposal would implicitly require other countries to follow the FDA’s decision. “Not necessarily,” said Bill Falstitch, vice president of global supply chain for New York City-based vaccine manufacturer Pfizer.
right time?
Offering the COVID-19 vaccine alongside the flu jab could increase adoption, but Jerin also questioned plans to offer the latest jab in the fall in the US. During the pandemic, the United States saw waves of COVID-19 at the end of the summer, in addition to a significant winter spike. This could suggest that getting the vaccine earlier in the year would be better, he says.
But Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research in Silver Spring, Maryland, said giving jab before the winter surge could prevent hospitalization surges. increase. In the winter, clinics are overrun with people with flu and respiratory syncytial virus (RSV), and some US hospitals are nearing capacity this season.
harmonious composition
At the same meeting, the Vaccine Advisory Committee unanimously supported the agency’s proposal to adopt a single COVID-19 vaccine composition for primary and booster doses. People in the United States are now completing the primary COVID-19 vaccination series. He will receive at least two doses of vaccines manufactured by Pfizer-Biontech, Moderna, or Novavax, or one dose of the Johnson & Johnson vaccine. A booster follows two months later. As for the boosters, Pfizer Biotech and Moderna initially offered booster doses of the original vaccine, but now both companies only offer “bivalent” boosters containing multiple strains of his SARS-CoV-2. offers.
Bivalent booster uptake rates are low in the United States, with approximately 15% of eligible individuals receiving 2-strain jabs. Some experts say many people are getting multiple combination vaccines, leading to confusion about which type of booster to give and when.
Megan Ranney, a physician and public health expert at Brown University in Providence, Rhode Island, said: “From a behavioral science perspective, we need to move to a more standardized schedule if we are to maintain our ability to vaccinate a country.” “These changes make a lot of sense,” she added, as they reduce some of the confusion and allow the jab to be offered alongside the annual flu vaccine. “
Future decisions
Standardizing the vaccine composition of the primary and booster series will likely mean that the bivalent vaccine will become the primary formulation for those who have not yet received the primary series.
Bivalent boosters currently in use in the US, UK and elsewhere target both the “ancestral” SARS-CoV-2 and Omicron strains circulating at the start of the pandemic. CDC data shared at the advisory board found that people over the age of 5 who received only single-strain boosters were twice as likely to die of COVID-19 as those who received bivalent boosters. However, even with boosters, overall mortality from COVID-19 is reduced.
Some conference panelists had concerns about the decision to use bivalent formulations rather than single-strain updates in future vaccines. Scientists noted that there is little data on the efficacy of bivalent vaccines when administered as a primary series. Also, some studies suggest that the inclusion of ancestral strains may blunt the effectiveness of vaccines against omicron due to a phenomenon called immune imprinting.
At the meeting, Marks said the advisory committee would convene again in May or June to discuss whether a change in formulation was warranted, and then include one strain of SARS-CoV-2 in the updated vaccine. Strains you mentioned discussing whether to include only or multiple strains. It’s an important scientific question, Lanny says, but in the meantime, “especially if you’re older or have chronic conditions, it’s better to use boosters during a surge than not to use boosters.” It’s better than that.”
This article is reproduced with permission and was first published on January 27, 2022.
