The change shows that the FDA is trying to be more nimble in keeping up with a changing virus. The exact formula has not been tested in humans yet, but studies have shown that vaccines adapted to fight an earlier version of omicron increased the short-term immune response in humans to a modest degree compared to several shots of the original. The Agency will in part depend on these data when evaluating the new vaccines.
On Thursday, the FDA advised companies to create a two-part vaccine for an autumn amplifier campaign. One part of the vaccine will be the original formula, based on the version of the virus that spread globally in early 2020. The other part will be based on the BA.4 and BA.5 omicron subvariants which today make up half of the strains sequenced in the United States.
It is quite possible that BA.4 and BA.5 will be darkened by new varieties by the autumn, but the hope is that a new shoot will help to expand immunity, since they are closer to where the virus is today. A Pfizer scientist showed data to FDA advisers on Tuesday that a vaccine based on these versions of omicron appeared to generate a stronger immune response in mice.
Detection of the vaccine against the coronavirus
For a year and a half, coronavirus vaccines based on the original version of the virus have provided robust protection, especially against serious illness. But immunity declines over time, and the virus has proven to be deceptive, creating a growing Greek alphabet of new varieties that are more contagious and good at slipping past people’s immune systems.
“As we enter the fall and winter, it is crucial that we have safe and effective vaccine enhancers that can provide protection against circulating and new variants to prevent the most serious consequences of covid-19,” the FDA statement said.
Experts have felt concerned that such an impact decision must be made based on very limited data. It is possible that the change may result in a demonstrable increase in people’s protection against serious illness and perhaps also infection, but it is not certain.
“I think the FDA here is making a best guess about what they think is the right thing to do, and it may turn out to be good, and it may not,” said John Moore, professor of microbiology and immunology at Weill Cornell. medicine. “We do not know and have no real way of knowing it.”
The modified vaccine will be used as a booster. People who still receive the first injections will continue to receive the original version of the vaccine.
People who are unvaccinated or unboosted should not delay vaccination in hopes of getting a new syringe, especially given the high levels of transmission, said an FDA official who requested anonymity because they were not authorized to speak. People will still potentially be eligible for the booster by the fall, and all vaccines are best at protecting against serious illness and hospitalization.
The federal government announced on Thursday that it had agreed to buy 105 million doses of Pfizer’s restarted vaccine for $ 3.2 billion. At $ 30.50 per dose, it is a premium over the first contracts the government entered into for the original vaccine in 2020, when the vaccines were $ 19.50 per dose.
Pfizer has said that the price of the vaccine will probably rise after the pandemic, and this may not be the case.
“We expect this to be only the second price increase between pandemic pricing and future commercial pricing,” SVB Securities Research analysts wrote in a note analyzing the announcement.
Modern President Stephen Hoge told an FDA advisory committee that his company would take until late October or early November to create a vaccine based on the BA.4 and BA.5 versions of omicron. It was unclear on Thursday what the company’s timeline would be for delivering renewed doses to the United States.