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In a day-long virtual meeting, a panel of experts advising the Food and Drug Administration came out in general support of efforts to develop new COVID-19 vaccines designed for diversification.
The committee was not asked to vote on a specific recommendation to the agency, but instead discussed a framework for deciding when to replace viral strains or strains used for future vaccines, including booster.
“I think we’re in an unknown area because there’s been a lot of SARS-CoV-2 that has never happened before,” said Dr. Arnold Monto, an emeritus professor at the University of Michigan and acting chairman of the committee.
The panel will probably meet again in May or June to consider more specific proposals for the reform of the Covid-19 vaccine.
The mechanism used to match the strains that carry annual flu vaccines is a model that could inform the process for COVID-19, but much is still unknown about how the coronavirus may change and the complete difference between the influenza virus and SARS-CoV-2. There are. .
Fall targets for new types of boosters
Critical consideration is whether an alternative-specific booster should be made available this fall. The emergence of the Omicron variant, and more recently a subvariate called BA.2, has sharpened the question. Vaccines now used in the United States are based on the size of the virus that spread at the beginning of the epidemic and are less effective against some subsequent strains.
“Although we have seen a big drop in the number of COVID-19 cases in the country, the virus continues to circulate and it will continue to do so and potentially create a wave of increase in the number of cases,” said Dr Peter. Marks, head of the FDA’s Center for Biological Evaluation and Research, opened the meeting. “This is of particular concern because we are going through the autumn and winter seasons.”
Marx also noted that the coronavirus would take longer to develop in the United States until the fall.
In the morning session, Israeli researchers presented information about the single booster dose of the Pfizer-BioNTech vaccine and the increased protection of the second booster against infection, which was transient and serious illness, which was chronic. The rapid spread of the Omicron variant contributes to the reduction of protection from immunization through a booster.
Israeli authorities approved a second booster in early January for those 60 years of age and older and at high risk or who work in healthcare. Israel’s experience contributed to the FDA’s decision in late March to approve a second booster dose for people 50 years of age or older, as well as for others with uncompromising immunity.
Predicting viral evolution ‘difficult’
Rapid genetic mutations in the coronavirus are driving its ability to vaccinate and prevent immunity from previous infections. Constant changes complicate decisions about which strains should be included in new vaccines.
“In general, from what we’ve seen, we should expect a lot of evolution in front of us, and we should have a way to keep up with this evolution in terms of the vaccination platform,” said Trevor Bedford, a researcher on viral evolution. Seattle’s Fred Hutchinson Cancer Center.
He said it was “quite difficult” to predict where the virus would go. The coronavirus is developing faster than the flu. Significant new strains of the coronavirus have appeared in a matter of months, instead of the years it took to make such a leap into the flu.
Based on the rate of evolution of the coronavirus so far and uncertainty about what lies ahead, Bedford estimates that a dangerous new form like Omicron may not occur in about a year and a half or more than a decade.
There is not much time to change the vaccine in time for vaccination this fall. “If you don’t go through a clinical trial in early May, I think it will be very difficult to find enough products among manufacturers to meet the demand,” said Robert Johnson, deputy assistant secretary at Federal Biomedical Advances. Research and Development Authority.
The FDA’s Marx acknowledges that there is a narrow schedule for deciding on booster makeup, but there may be “some shaky houses” that may allow fixation in May or June.
There is a lot to decide. “The second booster dose approved by the FDA was” a stopgap measure “to help protect the most vulnerable,” he said.
The goal of a reformed booster later this year, Marx said, was to “raise again to protect us from a wave that could come at a time of maximum risk.”
In his concluding remarks, Monto, chairman of the committee, said: “We would like to see an annual vaccine for influenza, but understand that the evolution of the virus will indicate how we will respond.”
Rob Stein contributed to this report.