Johnson & Johnson trots out two-dose COVID vaccine data as it builds case for boosters

Johnson & Johnson's data release adds to evidence that its COVID-19 vaccine performs better when a booster is added to the first shot. (Pixabay)

Providing a single-dose vaccine was the edge Johnson & Johnson wanted to exploit in the race to inoculate against COVID-19. Now the company is touting data that a second shot of its vaccine improves on the protection afforded by just the one dose that's currently authorized.

Citing evidence from a phase 3 study, J&J showed that a second shot of its COVID-19 vaccine given two months after the first provides 94% protection against symptomatic COVID-19 and 100% protection against a severe form of the disease when measured at least 14 days after the second dose. Additionally, the two doses given two months apart yield a four- to six-fold increase in antibody levels compared to those levels after just one dose.

The data, which comes from the company's phase 3 ENSEMBLE trial, also showed that protection against symptomatic COVID-19 across its global sites was 75%. 

The company has provided the data to the FDA and said it will also submit it to other regulators including the World Health Organization.

RELATED: Johnson & Johnson touts antibody response for COVID-19 booster 8 months after original vaccination

Last month, J&J shared data from a separate trial that showed that a booster shot of its vaccine given after six months after the first dose provided a nine-fold increase in antibodies, which climbed to 12-fold after four weeks, regardless of the age of the recipients.

The news comes four days after an FDA advisory panel recommended emergency use authorization for a third shot of the Pfizer-BioNTech vaccine to be given six months after the initial approved two-dose vaccination series, but only in a narrower population than Pfizer's approval request. By a 16-2 vote, the panel recommended rejection of the companies’ bid to open boosters to everyone 16 and older. The panel instead settled on those 65 and older and others with conditions or occupations that put them at high risk. A decision by the FDA is expected this week.

RELATED: FDA advisers reject Pfizer COVID-19 boosters for all, but agree to shots for elderly and high risk

As for J&J, Cantor Fitzgerald analyst Grace Chen says that the “data is timely.”

J&J has administered 14.9 million doses of its vaccine in the United States, said the CDC, compared to 221.1 million doses administered by Pfizer and 149.9 million by Moderna.