FDA Staff Endorses J&J’s Single-Shot COVID Vaccine, Advisory Committee to Convene on Friday

February 24th, 2021 – The US Food and Drug Administration (USFDA) staff has deemed Johnson & Johnson’s single-shot COVID-19 vaccine safe and effective. In a briefing document published on Wednesday morning, the FDA said that the data analysis of the vaccine “supports a favorable safety profile with no specific safety concerns identified” and the review has found the vaccine to have met the criteria for Emergency Use Authorization (EUA).

On Friday, the Vaccines and Related Biological Products Advisory Committee (VRBPAC) will convene to provide advice and recommendations regarding the EUA. If the FDA does approve, then J&J’s vaccine will become the third to bag emergency authorization in the US following the mRNA vaccines from Pfizer/BioNTech and Moderna.

The Single-Shot Vaccine

J&J’s Ad26.COV2.S is a replication-incompetent recombinant adenovirus serotype 26 (Ad26) vectored vaccine. It encodes a full-length, stabilized variant of the SARS-CoV-2 spike protein, and around 5×10¹⁰ virus particles will be administered as a single intramuscular injection of 0.5 mL dosage.

Ad26.COV2.S was evaluated in the Phase 3 ENSEMBL trial of 45,000 participants across the US, Latin America, and South Africa. The vaccine demonstrated an overall efficacy of 66% (72% in the US, 66% in Latin America, and 57% in South Africa) in preventing moderate to severe COVID-19 and 85% in preventing severe disease.

Although these numbers look poorer than the 95% and 94% efficacies registered by Pfizer and Moderna vaccines, respectively, experts opine that Ad26.COV2.S must be judged differently. The ENSEMBL trial was conducted in countries where several new infections were caused by emerging coronavirus variants, including the virulent B.1.351 variant first observed in South Africa, and the P2 variant first observed in Brazil.

Among the 6,736 vaccinated participants who were monitored, the most common solicited adverse reactions were injection site pain (48.6%), headache (38.9%), fatigue (38.2%), and myalgia (33.2%). Following the topline safety and efficacy results obtained in the trial, on February 4th, Janssen Biotech, Inc. submitted the EUA application to the FDA.

Gamechanger

J&J’s vaccine is touted to be a ‘gamechanger’ owing to its single-dose administration and the fact that it could be stored and transported at regular refrigerator temperatures. Ad26.COV2.S is estimated to remain stable at -20° Celsius for up to two years and at least three months in the 2° – 8° Celsius range. In contrast, the two mRNA vaccines require freezing temperatures and have to be administered as a two-dose vaccination. Besides, the encouraging efficacy data demonstrated against coronavirus variants—an area where the other two vaccines have reported weaker protection, might provide J&J’s vaccine an edge in the competition.

Earlier, the company promised to deliver 10 million and 25 million doses of the vaccine by the end of February and March. However, at a House Energy & Commerce Committee hearing on Tuesday, Dr. Richard Nettles, Vice President, U.S. Medical Affairs, Janssen, said, “We will have 20 million doses of the vaccine to be made available by the end of March, and we’re prepared to ship, immediately upon emergency use authorization, nearly 4 million doses of our vaccine,”. Nevertheless, he expressed confidence in delivering 100 million doses during the first half of 2021.

Related Article: Johnson & Johnson’s COVID-19 Vaccine Draws Mixed Reactions as it Registers 66% Efficacy

References

1. https://www.fda.gov/media/146217/download
2. https://www.reuters.com/article/us-health-coronavirus-vaccines-johnson-j/johnson-johnsons-one-shot-covid-19-vaccine-effective-safe-fda-staff-idUSKBN2AO1LS
3. https://www.jnj.com/johnson-johnson-announces-submission-of-application-to-the-u-s-fda-for-emergency-use-authorization-of-its-investigational-single-shot-janssen-covid-19-vaccine-candidate
4. https://www.hhs.gov/sites/default/files/janssen-corp-covid-19-vaccine-contract.pdf#page=17
5. https://docs.house.gov/meetings/IF/IF02/20210223/111226/HHRG-117-IF02-Wstate-NettlesR-20210223.PDF

Author

Rajaneesh K. Gopinath