J&J says second-dose study supports use of booster shots

“We look forward to discussing with public health officials a potential strategy for our Johnson & Johnson COVID-19 vaccine, boosting eight months or longer after the primary single-dose vaccination,” said Mathai Mammen, global head of research and development at J&J’s Janssen subsidiary.

The company said that clinical trials found a booster shot of its one-dose vaccine increased Covid-19 antibodies ninefold one month after vaccination, compared to the levels seen one month after the first shot. J&J said this was true for people 18-55 as well as those over 65, who received a lower booster dose.

J&J has submitted two papers describing the results to an online archive, but the analyses have not yet undergone peer review.

Findings released this month from a South African study of nearly 480,000 health care workers found J&J’s single-shot regimen was strongly protective against the Delta variant, cutting the risk of hospitalization by 71 percent and of death by 96 percent.