mRNA-1273 Has High Vaccine Effectiveness After Five Months

FRIDAY, Dec. 3, 2021 (HealthDay News) — The vaccine effectiveness of two doses of Moderna mRNA-1273 is 87.4 percent against COVID-19 infection and 95.8 and 97.9 percent against COVID-19 hospitalization and hospital death, respectively, according to a study published online Nov. 25 in The Lancet Regional Health: Americas.

Katia J. Bruxvoort, Ph.D., M.P.H., from Kaiser Permanente Southern California in Pasadena, and colleagues conducted a planned interim analysis of 352,878 individuals aged ≥18 years receiving two doses of mRNA-1273 ≥24 days apart (Dec. 18, 2020, to March 31, 2021) matched to 352,878 randomly selected unvaccinated individuals with follow-up through June 30, 2021. Outcomes were COVID-19 infection or severe disease.

The researchers found that the vaccine effectiveness was 87.4, 95.8, and 97.9 percent against COVID-19 infection, COVID-19 hospitalization, and COVID-19 hospital death, respectively. Vaccine effectiveness was higher against symptomatic than asymptomatic COVID-19 (88.3 versus 72.7 percent), and was generally similar across subgroups based on age, sex, and race/ethnicity. Among individuals with a history of COVID-19 infection, vaccine effectiveness ranged from 8.2 to 33.6 percent. The most prevalent severe acute respiratory syndrome coronavirus 2 variants were alpha, epsilon, delta, and gamma (41.6, 17.5, 11.5, and 9.1 percent, respectively); by June 2021, delta increased to 54.0 percent of variants.

“This study adds evidence of real-world Moderna COVID-19 vaccine effectiveness, particularly among the general population,” a coauthor said in a statement. “Our follow-up on these fully vaccinated patients occurred through June 2021, a period that overlapped with the emergence of the Delta variant in the United States.”

Several authors disclosed financial ties to pharmaceutical companies, including Moderna, which manufactures the mRNA-1273 vaccine and funded the study.

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