Johnson and Johnson COVID-19 Vaccine is 85% Efficacious in Preventing Severe Disease

Johnson & Johnson (J&J) announced today its JNJ-78436735 COVID-19 vaccine was 85% effective in preventing severe disease across all regions studied—28 days after vaccination.

These regions included the US, Latin America, and South Africa. Efficacy against severe disease increased over time with no cases in vaccinated participants reported after day 49 in all adults 18 years and older.

Additionally, the vaccine's level of protection against moderate to severe COVID-19 infection was 72% in the United States, 66% in Latin America, and 57% in South Africa—28 days post-vaccination.

The single dose investigational vaccine, which is being developed by the Janssen Pharmaceutical Companies of Johnson & Johnson, is more commonly referred to as the Ad26.COV2.S vaccine, and is a recombinant, replication-incompetent adenovirus serotype 26 (Ad26) vector encoding a full-length and stabilized SARS-CoV-2 spike (S) protein.

“These topline results with a single-shot COVID-19 vaccine candidate represent a promising moment. The potential to significantly reduce the burden of severe disease, by providing an effective and well-tolerated vaccine with just one immunization, is a critical component of the global public health response,” Johnson & Johnson Vice Chairman of the Executive Committee and Chief Scientific Officer Paul Stoffels, MD, said. “A one-shot vaccine is considered by the World Health Organization to be the best option in pandemic settings, enhancing access, distribution and compliance. Eighty-five percent efficacy in preventing severe COVID-19 disease and prevention of COVID-19-related medical interventions will potentially protect hundreds of millions of people from serious and fatal outcomes of COVID-19. It also offers the hope of helping ease the huge burden placed on healthcare systems and communities.”

These results come from the company’s Ensemble study being conducted in eight countries and three regions.

“The J&J vaccine turns in a fantastic result,” former FDA Commissioner Scott Gottlieb, MD. tweeted this morning. “We now have 3 highly effective vaccines. This vaccine showed sustained (and increasing!) immune protection over time, perhaps from a robust early induction of memory immune cells (CD4 and CD8). The protection was strong and durable.”