J&J vaccine booster dose displays 94 percent protection

Johnson & Johnson announced Phase III data demonstrating effective COVID-19 protection and an increase in protection with a booster dose.

3D illustration of vials labelled 'COVID-19 Vaccine' in a row

Johnson & Johnson have announced new data reinforcing the strong and long-lasting protection of its COVID-19 vaccine. Novel data also showed that protection against COVID-19 increases when a booster dose of the Johnson & Johnson vaccine (the Janssen COVID-19 Vaccine) is administered. The safety profile of the vaccine remained consistent and was generally well-tolerated when administered as a booster.

The Phase III study was the largest real-world evidence study for a COVID-19 vaccine reported to date in the US and demonstrated stable vaccine effectiveness of 79 percent for COVID-19-related infections and 81 percent for COVID-19-related hospitalisations.

There was no evidence of reduced effectiveness over the study duration, including when the Delta variant became dominant in the US Sequencing data were not available for analysis. The study included 390,000 people who received the Janssen COVID-19 Vaccine versus approximately 1.52 million unvaccinated people matched on age, sex, time, three-digit zip code, and comorbidities and predictors for COVID-19 infection severity conducted from March to late July 2021.

These data were consistent with the Phase III ENSEMBLE trial, where strong protection against severe/critical disease and death was observed at least 28 days post-final vaccination:

  • 75 percent overall efficacy against severe/critical COVID-19, across all age cohorts and all countries included in the study
  • 74 percent efficacy in the US against severe/critical COVID-19; 89 percent against hospitalisation; and 83 percent against COVID-19-related death.

The Phase III ENSEMBLE 2 study showed that an additional shot of the Janssen COVID-19 Vaccine given 56 days after the first provided:

  • 100 percent protection against severe/critical COVID-19 – at least 14 days post-final vaccination
  • 75 percent protection against symptomatic (moderate to severe/critical) COVID-19 globally
  • 94 percent protection against symptomatic (moderate to severe/critical) COVID-19 in the US.

When a booster of the vaccine was given two months after the first shot, antibody levels rose to four to six times higher than observed after the single shot. When a booster of the Janssen COVID-19 Vaccine was given six months after the single shot, antibody levels increased nine-fold one week after the booster and continued to climb to 12-fold higher four weeks after the booster. All rises were irrespective of age.

“Our large real-world evidence and Phase III studies confirm that the single-shot Johnson & Johnson vaccine provides strong and long-lasting protection against COVID-19-related hospitalisations. Additionally, our Phase III trial data further confirm protection against COVID-19-related death,” commented Dr Mathai Mammen, Global Head of Janssen Research & Development at Johnson & Johnson. “Our single-shot vaccine generates strong immune responses and long-lasting immune memory. And, when a booster of the Johnson & Johnson COVID-19 vaccine is given, the strength of protection against COVID-19 further increases.”