improved, it will be important to look at all the data and options in order to optimize the vaccines that are available.”
An advisory committee to the U.S. Centers for Disease Control and Prevention plans to meet next Wednesday and Thursday to make recommendations on how the booster doses should be used. Some federal officials seemed dubious about the company’s claim about the efficacy of one dose.
Panel members expressed concern about the size of the study Johnson & Johnson used to ask for authorization of a six-month interval. “I’m not sure why you’re asking for an indication that would apply to millions of patients with a data set that includes 17 patients,” Dr. Eric Rubin, an adjunct professor of immunology and infectious diseases at the Harvard T.H. Chan School of Public Health in Boston says.
The panel will also hear from a scientist who helped lead the NIH study that found Johnson & Johnson vaccine recipients may benefit more from a booster of the Moderna or Pfizer-BioNTech vaccine.
Preliminary data from the “mix and match” study showed that those who got a Johnson & Johnson shot followed by a Moderna booster saw their antibody levels rise 76-fold within 15 days, while those who received another dose of Johnson & Johnson saw only a fourfold rise in the same period. A Pfizer booster raised antibody levels in Johnson & Johnson recipients 35-fold.
The trial only looked at antibody levels, which are only one component of the immune system.
Dr. Johan Van Hoof, a Johnson & Johnson executive, referred to that NIH data during the panel meeting, saying, “These findings are important, but only a piece of the puzzle, and they don’t give the complete picture.”
Even so, some experts said the evidence was still pointing to switching vaccines for booster shots.
“Prior to, I don’t know, November or December of 2019, the human species are immunologically naive to this virus. But any single-shot vaccine was likely to induce a primary response and the second shot would be necessary,” James E.K. Hildreth, president of Meharry Medical College, in Nashville, Tennessee says. It was always going to be necessary for J&J recipients to get a second shot.”