FDA scientists strike favorable tone ahead of vote this week

The staff of the Food and Drug Administration on Wednesday struck a more favorable tone on Johnson & Johnson Covid-19 booster shots, saying there may be a benefit to administering a second dose two months after the initial shot.

The staff acknowledged, however, the data to support boosters was limited and the agency hasn’t verified all the information yet.

“Although not independently confirmed by FDA from datasets, summaries of the data suggest there may be a benefit in a second dose administered approximately 2 months after the primary dose, when compared to the efficacy seen in the pivotal study COV3001,” they wrote in a 54-page document made public Wednesday.

They also said one J&J dose was consistently less effective than the mRNA vaccines made by Pfizer and Moderna in clinical trials and in real-world studies.

“The highest effectiveness estimates (including for more severe COVID-19 disease) across clinical trials and real-world effectiveness studies evaluating the Janssen COVID-19 Vaccine are consistently less than the highest effectiveness estimates for the mRNA COVID-19 vaccines,” they said.

Overall, data shows the single-shot J&J vaccine “still affords protection against severe COVID-19 disease and death in the United States.”

The report by FDA scientists is meant to brief the agency’s Vaccines and Related Biological Products Advisory Committee, which meets Friday to discuss data on the safety and effectiveness of a second J&J shot in adults. The documents published offer a glimpse of the agency’s view on additional shots.

Unlike Pfizer’s and Moderna’s two-shot mRNA vaccines, J&J hoped to offer a one-shot solution that would protect the public enough to help bring an end to the coronavirus pandemic. But its protection at 72% in the U.S. was viewed by some as inferior to Moderna’s and Pfizer’s vaccines, which both touted efficacy rates above 90%.

A second dose of J&J’s shot boasts similar performance to the mRNA vaccines, boosting protection from symptomatic infection to 94% when administered two months after the first dose in the United States, according to company data released Sept. 21. J&J, which uses a modified adenovirus to induce an immune response, asked the agency to approve a booster shot of its one-dose vaccine for people ages 18 and older on Oct. 5.

Still, in the documents released Wednesday, FDA scientists suggested there wasn’t enough data on the older people or on the fast-moving delta variant to draw a conclusion on the benefit of boosters.

They said the sample size J&J provided on individuals age 60 and older “limits the ability to conclude about an increase in efficacy after the second dose in this group.”

“Finally, the small number of accused cases confirmed to be caused by the Delta variant precludes any conclusion regarding efficacy against the variant,” they added.

The staff said there were no new concerning safety issues…