J&J says its vaccine booster shot raises antibody levels 9-fold
In the midst of a delta variant surge, a new study finds that giving a booster dose of the Johnson & Johnson shot six months after primary vaccination results in a nine-fold increase of a crucial antibody response, according to a company press release.
Meanwhile, a prior study found that people vaccinated with the Johnson & Johnson vaccine still had a durable immune response at least eight months later, even without a booster.
![PHOTO: A nurse fills a syringe with Johnson & Johnson's Janssen Covid-19 vaccine at a clinic hosted by The Tournament of Roses in partnership with the Pasadena Public Health Department, August 19, 2021 at Tournament House in Pasadena, California.](https://s.abcnews.com/images/Health/jandj-vaccine-210_hpMain_20210824-233232.jpg)
Collectively, the findings could help inform the U.S. government's recommendations about booster shots for the 14 million people who received the single-shot Johnson & Johnson vaccine.
Boosting after six months "appears to be safe, and boosts immune responses substantially," Dr. Dan Barouch, Ph.D., director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center, told ABC News.
-ABC News' Sony Salzman