ENSEMBLE Research: J&J COVID-19 Vaccine Part Three Interim Evaluation

Johnson & Johnson (J&J) Coronavirus Disease 2019 (COVID-19) vaccine prevents 66% of both moderate and severe COVID-19 on day 28 after vaccination. This emerges from the interim phase 3 results published by the National Institutes of Health.1

J & J’s vaccine, Ad.26.COV2, is a single injection and can be refrigerated for months. It is indicated for adults over the age of 18.

In the interim analysis (N = 43,783), 468 cases of symptomatic COVID-19 cases in 8 countries were assessed. The study endpoint was moderate and severe COVID-19 in all volunteers 28 days after vaccination.

Overall, the results show that the J&J vaccine is 66% effective in preventing moderate and serious illnesses and has been shown to be effective against emerging virus variants on day 28. The level of protection varied depending on the geographical location:

  • USA: 72%
  • Latin American countries: 66%
  • South Africa: 57%

The vaccine was 85% effective in preventing severe or critical COVID-19 in all geographic areas. It also demonstrated full protection against hospitalizations related to COVID-19 and death on day 28 after vaccination

Protection was generally uniform across race, age groups, and all variants and regions examined. This is particularly relevant in South Africa, where over 95% of infections came from the B.1.351 line.

The analyzes reported 3 deaths in the vaccine group (0 related to COVID-19) and 16 deaths in the placebo group (5 related to COVID-19).


1. Janssen vaccine against COVID-19: interim analysis of published phase 3 clinical data. National Institute of Health. January 29, 2021. Accessed February 9, 2021. data -released

2. Johnson & Johnson announces that the single vaccine candidate Janssen COVID-19 met the primary endpoints in the interim analysis of its Phase 3 ENSEMBLE study. Johnson & Johnson. January 29, 2021. Accessed February 9, 2021. interim -analysis-his-phase-3-ensemble-study

This article originally appeared on Infectious Disease Advisor

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