A Big Day for the Johnson & Johnson Single-dose COVID-19 Vaccine

When the histories of the COVID-19 pandemic are written, today and the ones following are likely to stand out. A single-dose vaccine against the disease got the go-ahead.

The FDA Vaccines and Related Biological Products Advisory Products Advisory Committee unanimously endorsed the third U.S. COVID-19 vaccine, produced by Janssen, a subsidiary of Johnson & Johnson (J&J). An emergency use authorization by the FDA is expected to follow shortly.

An FDA briefing document for the committee said the vaccine was 66.1% effective against moderate-to-severe COVID-19. The briefing document, which is a review of the data submitted by Johnson & Johnson by FDA staffers, says lower effectiveness was seen in a subgroup of the study volunteers in the phase 3 trial who were 60 and older with comorbidities. That difference narrowed, though, once the scope of the analysis was broadened. The briefing document says a safety analysis through Jan. 22 that included a median follow-up period of two months “supported a favorable safety profile with no specific safety concerns identified that would preclude issuance of an EUA.”

The committee of outside experts will consider other evidence besides the briefing document. And the committee has just advisory role to the agency.

It would be shocking if the committee didn’t recommend an EUA for the Johnson & Johnson vaccine and if the FDA didn’t issue one, maybe as soon as tomorrow.

The Johnson & Johnson is considerably less effective than the two-dose Pfizer-BioNTech and Moderna vaccines, which are 95% effective. But the Johnson & Johnson vaccine has the advantage of being a single dose. Moreover, it’s 85% effectiveness against severe COVID-19 cases approaches that of the Pfizer-BioNTech and Moderna vaccines.

Helen Branswell at Stat has cautioned against side-by-side comparisons of the vaccines because there were subtle but perhaps importance difference endpoints of the trials and how and when COVID-19 cases were counted. Also, the Pfizer-BioNTech and Moderna trials were conducted before the U.K. and South African variants emerged.