J&J vaccine provides durable immunity, including against variants
Data now published in a major journal show that the Johnson & Johnson COVID-19 vaccine generated strong activity against SARS-CoV-2 for at least 8 months, including against variants of concern.
The results were published in a correspondence today in The New England Journal of Medicine, several weeks after Johnson & Johnson reported them in a news release and the researchers submitted them to a preprint server.
In the paper, Dan H. Barouch, MD, PhD, director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center and professor of medicine at Harvard Medical School, and colleagues report the 8-month durability of humoral and cellular immune responses among 20 people who received the Johnson & Johnson vaccine in one or two doses, and five people who received a placebo.
According to the study, they evaluated the antibody and T-cell responses of 10 people 8 months after they received a single dose of the vaccine, and 10 people 6 months after they received two doses. They also tested the performance of the vaccine against wild-type SARS-CoV-2 and the alpha (B.1.1.7), kappa (B.1.617.1), delta (B.1.617.2), gamma (P.1), epsilon (B.1.429) and beta (B.1.351) variants.
Barouch and colleagues reported detecting antibody responses in all vaccine recipients on day 239, with the median binding antibody titer against the wild-type SARS-CoV-2 receptor-binding domain reaching 645 on day 29, 1,772 on day 57, 1,962 on day 71 and 1,306 on day 239. The median WA1/2020 pseudo-virus neutralizing antibody titer was 272 on day 29, 169 on day 57, 340 on day 71, and 192 on day 239, and titers were similar when the analyses were restricted to participants who had received the single-shot vaccine regimen, the researchers said.
Additionally, the study revealed that three vaccine recipients had a sharp increase in antibody responses during the study period, including one who had a breakthrough infection that was “minimally symptomatic” and two who had received a messenger RNA vaccine. Excluding these participants showed that antibody responses were relatively stable during the 8-month period, with a reduction in the median neutralizing antibody titer by a factor of 1.8 between peak response on day 71 and the time point for assessing durability on day 239, Barouch and colleagues said.
According to the study, recipients who received one dose had a median neutralizing antibody titer of 184 against the wild strain, 158 against the D614G variant, 147 against the alpha variant, 171 against the kappa variant, 107 against the delta variant, 129 against the gamma variant, 87 against the epsilon variant and 62 against the beta variant on day 239. The researchers said these data suggest “an expansion of neutralizing antibody breadth” associated with improved coverage of SARS-CoV-2 variants over time, including increased neutralizing antibody titers against these variants of concern.
“These data show that the Ad26.COV2.S vaccine elicited durable humoral and cellular immune responses with minimal decreases for at least 8 months after immunization,” they wrote. “The durability of humoral and cellular immune responses after Ad26.COV2.S vaccination with increased neutralizing antibody responses to SARS-CoV-2 variants over time, including after single-shot vaccination, further supports the use of the Ad26.COV2.S vaccine to combat the global COVID-19 pandemic.”