Johnson and Johnson announced publication in the New England Journal of Medicine of primary data from the Phase 3 ENSEMBLE clinical trial for its single-dose COVID-19 vaccine, developed by the Janssen Pharmaceutical Companies of Johnson and& Johnson (Janssen). The publication of the primary analysis follows the topline efficacy and safety data announced in January, showing the trial met all primary and key secondary endpoints, and found that the Johnson & Johnson single-dose COVID-19 vaccine prevented hospitalization and death across all study participants 28 days after vaccination.
These data demonstrated that, despite the high prevalence of emerging SARS-CoV-2 variants among COVID-19 cases in the study, including the South African variant of the B.1.351 lineage and the P2 lineage variant found in Brazil, vaccine efficacy was consistent against symptomatic infection, and the vaccine showed protection against COVID-19-related hospitalization and death as of 28 days after vaccination.
“This comprehensive evidence demonstrates that Johnson & Johnson’s single-shot COVID-19 vaccine offers protection and prevents hospitalization and death, including in countries where viral variants are highly prevalent,” said Paul Stoffels, M.D., Vice Chairman of the Executive Committee and Chief Scientific Officer at Johnson & Johnson. “Regardless of race and ethnicity, age, geographic location and comorbidities, these results remain consistent. A single-shot vaccine that provides this level of protection represents an important tool in the global fight against COVID-19, as we strive to help end this deadly pandemic. The safety and well-being of every individual who receives a Johnson & Johnson product remains our top priority, and these data reaffirm our confidence in the protective benefits of our COVID-19 vaccine.”
Trial Data Reflect 7-Day Onset of Efficacy, Prevention of Hospitalization and Death
The ENSEMBLE data demonstrated that Johnson & Johnson’s single-dose COVID-19 vaccine was 85 percent effective against severe/critical disease. Additionally, the trial met its co-primary endpoints of protecting against moderate to severe COVID-19 at 14 and 28 days after vaccination, achieving 67 percent efficacy at 14 days after vaccination; and 66 percent efficacy at 28 days after vaccination, with prevention against COVID-19-related hospitalization and death across all participants (N=44,325). Protection was generally consistent across race, age groups, including adults over 60 years of age (N=14,672), and those with and without comorbidities.
Onset of efficacy was evident seven days post-vaccination for severe/critical disease and 14 days post-vaccination for moderate to severe/critical disease. Importantly, vaccine efficacy continued to increase approximately eight weeks post-vaccination, which is the median duration for follow-up required by the U.S. Food and Drug Administration (FDA). Additional data collected since the announcement of topline results found no evidence of a decline in protection over time, after following approximately 3,000 participants for 11 weeks and 1,000 participants for 15 weeks.
Reactogenicity (reaction to vaccination) was higher with the Johnson & Johnson COVID-19 vaccine versus placebo, but reactions were generally mild-to-moderate and transient.
Vaccine Observed to be Effective against Emerging Variants of Concern
Variants observed in an ongoing analysis in the ENSEMBLE study included the B.1.351 (20H/501Y.V2) variant, which was identified in 95 percent of the COVID-19 cases in South Africa, and the variant from the P2 lineage, which was identified in 69 percent of COVID-19 cases in Brazil. In South Africa, vaccine efficacy was maintained with 64 percent efficacy against moderate to severe/critical disease, and 81.7 percent against severe/critical disease as of Day 28 post-vaccination. Efficacy was also maintained in participants in Brazil, with 68.1 percent efficacy against moderate to severe/critical disease, and 87.6 percent against severe/critical disease.
“Our COVID-19 ENSEMBLE data, published in the New England Journal of Medicine, demonstrate that, with a single shot, our vaccine offers a high level of activity across all variants and regions studied,” said Mathai Mammen, M.D., Ph.D., Global Head, Janssen Research & Development, Johnson & Johnson. “We believe these data support the important role our COVID-19 vaccine can play in helping to address the global pandemic that continues to threaten people and healthcare systems around the world.”
