A single-shot coronavirus vaccine from pharmaceutical giant Johnson & Johnson was effective at preventing illness, hospitalizations and deaths in global trial. But its protection against sickness was stronger in the United States and weaker in South Africa, where a worrisome coronavirus variant now dominates.
The results, once granted emergency use authorization by the FDA, would put a third vaccine on the market in the United States. A third vaccine could accelerate the ability to broaden immunity, as variants that challenge the current generation of vaccines spread across the world.
The vaccine trial was primarily designed to measure how well the vaccine prevented illness. It was 66 percent effective overall at preventing moderate and severe disease: it was 72 percent effective at protecting against moderate to severe illness in the United States, but it was 66 percent effective in Latin America and 57 percent effective in South Africa, where concerning variants have taken root.
Single-shot Johnson & Johnson vaccine 66% effective against moderate to severe covid-19, but worked less well in variant hot spot https://t.co/jFMLkZHr9i
— The Washington Post (@washingtonpost) January 29, 2021
Company officials emphasized the vaccine was 85 percent effective at preventing severe illness, and there were no cases of COVD-related hospitalization and death in people who received the vaccine. There were five COVID-related deaths in the trial, all in people who received the placebo, not the vaccine.
Johnson & Johnson is expected to apply for emergency use authorization from the Food and Drug Administration late next week. If the review follows the path of two earlier vaccine candidates, the shot could be authorized and available to the public by March.
The J&J vaccine uses a different technology than the two FDA authorized mRNA vaccines. This vaccine employs ‘a harmless cold virus’ to deliver a gene that carries the blueprint for the spiky protein found on the surface of the coronavirus. The virus infects cells, which then follow the genetic instructions to construct a replica of the coronavirus spike.
In contrast, the Pfizer and Moderna vaccines use a strip of genetic material called messenger RNA to instruct cells to build the spiky protein found on the surface of the coronavirus. In both cases, the immune system learns to recognize the real virus by mustering an immune response to the spike.
References:
- https://www.washingtonpost.com/health/2021/01/29/covid-vaccine-johnson-and-johnson
- https://www.washingtonpost.com/health/2020/09/23/coronavirus-vaccine-jj-single-shot/?itid=lk_inline_manual_2