Johnson & Johnson vaccine efficacious upto 8 months after COVID-19 vaccination: NEJM
In a pre-print research paper, researchers have highlighted that Ad26.COV2.S ( Johnson & Johnson)vaccine elicited durable humoral and cellular immune responses with minimal decreases for at least 8 months after immunization. The team further observed an expansion of neutralizing antibody breadth against SARS-CoV-2 variants over this time period, including against the more transmissible B.1.617.2 variant and the partially neutralization-resistant B.1.351 and P.1 variants, which suggests maturation of B-cell responses even without further boosting. The interesting findings have been put forth in the New England Journal Of Medicine.
Interim immunogenicity and efficacy data for the Ad26.COV2.S vaccine for COVID-19 have recently been reported. In the recent study, a team of researchers under Dan H. Barouch, from Center for Virology and Vaccine Research,Boston, USA have described the 8-month durability of humoral and cellular immune responses in 20 individuals who received one or two doses of 5×1010 vp or 1011 vp Ad26.COV2.S and in 5 participants who received placebo.
The team further evaluated antibody and T cell responses on day 239, which was 8 months after the single-shot vaccine regimen (N=10) or 6 months after the two-shot vaccine regimen (N=10). "We also report neutralizing antibody responses against the parental SARS-CoV-2 WA1/2020 strain as well as against the SARS-CoV-2 variants D614G, B.1.1.7 (alpha), B.1.617.1 (kappa), B.1.617.2 (delta), P.1 (gamma), B.1.429 (epsilon), and B.1.351 (beta)." the team elaborated.
Results have revealed some new facts.
- Antibody responses were detected in all vaccine recipients on day 239 .
- The median WA1/2020 pseudovirus neutralizing antibody titer was 272 on day 29, 169 on day 57, 340 on day 71, and 192 on day 239; titers were similar when the analyses were restricted to participants who had received the single-shot vaccine regimen.
- Spike-specific interferon-γ CD8+ and CD4+ T-cell responses were evaluated by intracellular cytokine staining assays and also showed durability and stability over this time period.
- The durability of immune responses elicited by the Ad26.COV2.S vaccine was consistent with the durability recently reported for an Ad26-based Zika vaccine.
"These data suggested 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."the team concluded.
For full article follow the link: DOI: 10.1056/NEJMc2108829
Source: New England Journal Of Medicine.