Johnson and Johnson COVID-19 booster proves effective

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A study shows an additional dose of the vaccine gives the patient 94 percent protection against symptomatic COVID-19 in the U.S.

Johnson and Johnson says that a booster shot of their single-dose vaccine can boost protection against COVID-19; especially in the U.S.

According to a news release, a Phase 3 ENSEMBLE 2 study found that a second dose of the vaccine administered 56 days after the first provided 100 percent protection against severe or critical COVID-19, 75 percent protection against symptomatic COVID-19 globally, and 94 percent protection against symptomatic COVID-19 in the U.S. When the second shot is administered, it boosts antibody levels four to six times higher than what is observed after the initial dose.

When the booster shot was given six months after the initial dose antibody levels shot up nine-fold after a week and 12-fold after four weeks irrespective of the age of the patient, the release says.


A real-world evidence study of the single-dose regimen found that vaccine effectiveness in the U.S. was measured at 79 percent for COVID-19 related infections and 81 percent for hospitalizations with no evidence of reduced effectiveness even as the Delta variant became prevalent, according to the release.

“Our large real-world evidence and Phase 3 studies confirm that the single-shot Johnson & Johnson vaccine provides strong and long-lasting protection against COVID-19-related hospitalizations. Additionally, our Phase 3 trial data further confirm protection against COVID-19-related death,” Mathai Mammen, MD, PhD, global head of Janssen Research & Development at Johnson & Johnson, says in the release. “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.”

The release says that Johnson and Johnson has provided the available data to the Food and Drug Administration and will submit the data to other regulators across the globe.

“It is critical to prioritize protecting as many people as possible against hospitalization and death given the continued spread of COVID-19. A single-shot COVID-19 vaccine that is easy to use, distribute and administer, and that provides strong and long-lasting protection is crucial to vaccinating the global population,” Paul Stoffels, MD, viceice chairman of the Executive Committee and chief scientific officer at Johnson & Johnson, says in the release. “At the same time, we now have generated evidence that a booster shot further increases protection against COVID-19 and is expected to extend the duration of protection significantly.”