HealthDay News – A single dose of the human adenovirus type 26 vector encoding the coronavirus 2-spike protein (Ad26.COV2.S) with full-length severe acute respiratory syndrome (Ad26.COV2.S) protects according to a study published online April 21 in the New England Journal of Medicine.
Jerald Sadoff, MD, of Janssen Vaccines and Prevention in Leiden, the Netherlands, and colleagues randomly assigned adults to receive a single dose of Ad26.COV2.S or placebo in an international randomized study (19,630 received Ad26.COV2.S and 19,691 received placebo in the pro-protocol population) to study effectiveness against moderate to severe critical COVID-19.
The researchers found that Ad26.COV2.S protected against moderate to severe critical COVID-19 for at least 14 days after administration (effectiveness 66.9 percent) and at least 28 days after administration (66.1 percent). Greater efficacy of the vaccine was observed against severely critical COVID-19 (76.7 and 85.4 percent for onset after ≥ 14 days and after ≥ 28 days, respectively). The effectiveness of the vaccine was 52.0 and 64.0 percent, respectively, against moderate to severe critical COVID-19, with onset ≥ 14 days and ≥ 28 days after administration in cases in South Africa; 94.5 percent of these cases had the variant 20H / 501Y.V2. The effectiveness against seriously critical COVID-19 was 73.1 and 81.7 percent, respectively. Reactogenicity was higher with Ad26.COV2.S compared to placebo, but was mainly mild to moderate and transient. The incidence of serious adverse events was balanced between the groups. There were three and 16 deaths in the vaccine and placebo groups, respectively (none and five were COVID-19-related).
“The single-dose schedule and convenient storage conditions for this vaccine offer great benefits in terms of its global use and effectiveness,” the authors write.
The study was funded by Janssen Research and Development, a subsidiary of Janssen Vaccines and Prevention and part of the Janssen pharmaceutical companies of Johnson & Johnson.
Abstract / full text
COVID19 Diagnostic Tests General Infectious Diseases General Neurology