Citing phase-three trial data with up to 30,000 participants, the company said a second shot of its vaccine given about two months after the first increased its effectiveness from 72 to 94 percent in the U.S. against moderate to severe forms of the disease; meanwhile, its effectiveness increased from 66 to 75 percent against moderate and severe disease globally. A booster shot given six months after the first could be even more beneficial, with the data showing antibody levels shooting up twelvefold.
“A single-shot COVID-19 vaccine that is easy to use, distribute, and administer that provides strong and long-lasting protection is crucial to vaccinating the global population,” Paul Stoffels, Johnson & Johnson’s chief scientific officer, said in a statement. “At the same time, we now have generated evidence that a booster shot further increases protection against COVID-19 and is expected to extend the duration of protection significantly.”
Johnson & Johnson’s booster data has yet to be peer-reviewed or published in a scientific journal. So far, the drug company has not formally applied for authorization to offer booster shots to the general public, but it has shared the study’s results with the FDA and plans to do so with other health regulators and the World Health Organization.
For months, many J&J recipients — whose numbers are dwarfed by those who received the Moderna and Pfizer vaccines — have been confused about whether to seek out a second shot of any kind, despite little guidance on the question from the FDA or CDC. Last week, the FDA’s independent vaccine advisory committee rejected the idea of giving healthy Americans a third dose of the Pfizer vaccine in order to focus initial booster efforts on those who are elderly and immunocompromised. But Dr. Anthony Fauci said that recommendations on boosters for Moderna and Johnson & Johnson would be forthcoming in the next few weeks.