FDA Advisory Committee Discusses J&J Booster

October 18, 2021

On Friday, an advisory committee to the FDA convened to discuss an additional dose of Janssen’s Johnson & Johnson (J&J) COVID-19 vaccine. The voting question was:

Do available data support the safety and effectiveness of Janssen COVID-19 Vaccine for use under EUA as a booster dose in individuals 18 years and older at least 2 months after a single dose primary vaccination?

The committee voted yes unanimously (19 to 0) in favor of a booster dose.

Panelists clarified that their recommendation will not change the primary series from one to two doses. A single dose is consistent with immunity; the second dose will be viewed as a booster to the primary series. Those who have just received one dose are still considered fully vaccinated in terms of efficacy in protecting against COVID-19. A second dose raises efficacy by boosting neutralizing antibody titers, as well as CD4 and CD8 responses. The Johnson & Johnson booster dose will measure the same as the primary series.

One argument in favor of a booster is to raise efficacy that parallels the efficacy ratings of Pfizer and Moderna’s vaccines. While the efficacy of one dose of Johnson & Johnson’s vaccine is lower than Moderna and Pfizer, a single dose still neutralizes COVID-19 and prevents severe disease. A single J&J vaccine also does not appear to show waning efficacy; rather, receiving a booster increases the efficacy on par with the Moderna and Pfizer vaccines. Efficacy ratings from a 30,000 patient study increased from 74% to 94% after the administration of a booster dose (in US participants).