1 of 5 | The Moderna vaccine appears to be most effective at preventing serious COVID-19, but both it and Pfizer-BioNTech shot offer the most protection, the CDC says. File photo by Keizo Mori/UPI | License Photo
Sept. 17 (UPI) -- The Moderna COVID-19 vaccine is slightly more effective at preventing serious illness from the virus than its counterpart from Pfizer-BioNTech, according to data released Friday by the Centers for Disease Control and Prevention.
However, both two-dose vaccines, which have similar formulations, are better at reducing the risk for hospitalization due to coronavirus infection than the one-dose Johnson & Johnson shot, the data showed.
The Moderna vaccine lowers an infected person's risk for hospitalization -- or serious illness -- by 93%, starting two weeks after the second dose, the CDC researchers said.
The protection against serious illness created by the vaccine remains above 90% for at least four months, they said.
Meanwhile, the Pfizer-BioNTech vaccined reduces hospitalization risk by 88% among the fully vaccinated, but this protection drops to 77% four months later.
The one-dose Johnson & Johnson vaccine is 71% effective at lowering risk for hospitalization, the CDC said.
"Two-dose regimens of the Moderna and Pfizer-BioNTech mRNA vaccines provided a high level of protection against COVID-19 hospitalizations," the agency researchers wrote.
However, the Johnson & Johnson vaccine "had somewhat lower vaccine effectiveness," they said.
The findings are based on an evaluation of antibody levels among roughly 4,500 adults fully vaccinated against COVID-19, and a comparison of hospitalization rates among those inoculated and about 2,400 unvaccinated adults.
Antibodies are cells produced by the immune system to fight off viruses, and the vaccines are designed to boost anti-coronavirus antibody levels.
The new data includes vaccination and hospitalization data from March 11 to Aug. 15, which coincides with the rise of the more contagious Delta variant in the United States.
Last week, data from the CDC indicated that fully vaccinated people are more than 10 times less likely to be hospitalized due to COVID-19 and more than 10 times less likely to die from the disease.
Separately, studies in Israel found that the Pfizer-BioNTech shot offered up to 97% protection against infection and serious illness.
However, these studies involved the Alpha, or British, variant as opposed to the Delta variant, which is believed to have originated in India.
"These real-world data suggest some variation in levels of protection by vaccine," the CDC researchers said of their new data.
However, "all FDA-approved or authorized COVID-19 vaccines provide substantial protection against COVID-19 hospitalization," they said.