FDA Committee Supports Janssen COVID-19 Vaccine Booster

The Food and Drug Administration (FDA)’s Vaccines and Related Biological Products Advisory Committee voted unanimously (19 to 0) in favor of amending the Emergency Use Authorization (EUA) for the Janssen COVID-19 vaccine (Ad26.COV2.S) to include use of a booster dose in individuals 18 years of age and older at least 2 months after a single dose primary vaccination.

The panel reviewed safety and efficacy data from the phase 3 ENSEMBLE 2 study (ClinicalTrials.gov Identifier: NCT04614948), which evaluated the efficacy and safety of a booster dose of the Janssen COVID-19 vaccine in individuals 18 years of age and older. Participants received a booster dose 56 days after the first dose.

Findings showed that the booster dose provided 100% protection (95% CI, 33-100) against severe/critical COVID-19 at least 14 days post final vaccination and 94% protection (95% CI, 58-100) against symptomatic (moderate to severe/critical) COVID-19 in the US, suggesting a greater benefit with the second dose when compared with the efficacy seen in the ENSEMBLE study (ClinicalTrials.gov: NCT04505722).

Safety data showed no significant difference in adverse events following the booster dose vs after the first dose, though the data were limited by length of follow-up.

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Additionally, data were limited with respect to booster efficacy in individuals 60 years of age and older, as well as against the Delta variant.

While not bound to the panel’s recommendations, the FDA will take them into consideration when making the final decision on authorization.

The Janssen COVID-19 vaccine is currently authorized for active immunization to prevent COVID-19 caused by SARS-CoV-2 in individuals 18 years of age and older.


Vaccines and Related Biological Products Advisory Committee Meeting October 15, 2021. FDA Briefing Document. Accessed October 15, 2021. https://www.fda.gov/media/153037/download.