Why didn’t FDA advisers want to recommend Covid-19 booster shots for everyone?

“The stated goal of this vaccine has been to protect against serious illness,” Dr. Paul Offit, a professor of pediatrics at the Children’s Hospital of Philadelphia, told the meeting. “Data shows that these vaccines do exactly that,” he added. “It’s exactly what you’d expect.”

Even Pfizer said its vaccine was still very much preventing severe disease, hospitalizations and deaths in the US, with an effectiveness of more than 90%. The company argued that this might not last much longer, but many members of VRBPAC didn’t buy it.

They don’t see enough evidence to justify booster shots for everyone

“It is my opinion that we need this in our armamentarium — a booster dose now, particularly for the elderly and (those with) other high-risk conditions — but I share my colleagues’ angst about the sparsity of safety data,” said Dr. Mark Sawyer, a professor of clinical pediatrics at the University of California San Diego.

“I am hopeful that CDC rolls this out in a gradual fashion.”

Dr. Michael Kurilla, an infectious disease specialist at the National Center for Advancing Translational Sciences, said he suspected Pfizer went too far in extrapolating data on older people to a younger population.

“So it’s unclear that everyone needs to be boosted, other than a subset of the population that clearly would be at high risk for serious disease,” Kurilla said. “It is not clear to me that the data we are seeing now is applicable to the general population.”

They would like a lot more data and a chance to look for mistaken conclusions

Dr. Philip Krause, deputy director of the FDA’s Office of Vaccines Research and Review, noted that Pfizer was using data that had not been reviewed by experts.

“One of the issues in this is that much of the data that’s been presented and being discussed today is not peer-reviewed and has not been reviewed by FDA,” Krause said.

Krause, along with another FDA vaccine official, Marion Gruber, signed a paper published The Lancet earlier this week that argued it’s too soon to start giving people boosters.

Kurilla noted that Pfizer’s studies relied heavily on measurements of antibodies, without looking at other important aspects of immune response.

“It’s a little disappointing that there’s been very little reporting of the cellular immune responses and an entire focus on the neutralizing antisera,” Kurilla said. Immunologists point out that long-lasting protection comes from immune cells called B-cells and T-cells, and Pfizer only presented data on antibody response.

“We are lacking data, including strong data on vaccine doses that have been given,” said Dr. Hayley Ganz, a professor of pediatrics at Stanford University Medical Center.

They are worried…