People who received a booster six to eight months after their initial J&J shots saw antibodies increase nine-fold higher than 28 days after the first shot, Johnson & Johnson said.
The data comes from two Phase 2 studies conducted in the United States and Europe, the company said in a statement. Some of the 2,000 or so people in the studies got booster doses six months after their first doses of J&J’s Janssen vaccine.
“We have established that a single shot of our COVID-19 vaccine generates strong and robust immune responses that are durable and persistent through eight months. With these new data, we also see that a booster dose of the Johnson & Johnson COVID-19 vaccine further increases antibody responses among study participants who had previously received our vaccine,” Dr. Mathai Mammen, global head of research and development for Janssen, said in a statement.
Many people who received the J&J vaccine have been clamoring for information about whether they will need a booster shot. US federal government officials have said they are preparing to start offering a booster dose to people who got Moderna’s or Pfizer’s Covid-19 vaccine after data showed boosters can amp up the antibody response — and after studies started showing an uptick in infections in both vaccinated and unvaccinated people. The more transmissible Delta variant is partly to blame, experts say, as is a waning immune response.
Dr. Dan Barouch, a vaccine researcher at Beth Israel Deaconess Medical Center and Harvard Medical School told CNN “the boost at six months is going to look very impressive and substantially greater than what has already been reported in terms of the two month boost, and that is significant because it, in my opinion, the boost should not be at two months, but it really should be at six months or later.”