The study included 352,878 recipients of 2 doses of Moderna COVID-19 vaccine matched to 352,878 unvaccinated individuals by age, sex, race, and ethnicity.
Vaccinated individuals received 2 doses of Moderna COVID-19 vaccine from December 18, 2020, to March 31, 2021. Individuals in both groups were followed until June 30, 2021.
During follow-up, COVID-19 infections occurred among 289 vaccinated patients and 1,144 unvaccinated patients. Vaccine effectiveness against COVID-19 infection was 87%.
COVID-19 hospitalization occurred among 13 vaccinated and 182 unvaccinated patients, and COVID-19 in-hospital deaths occurred among 1 vaccinated and 25 unvaccinated patients.
Vaccine effectiveness against COVID-19 hospitalization was 96%, and vaccine effectiveness against COVID-19 in-hospital deaths was 98%.
Vaccine effectiveness against COVID-19 infection remained high across age, sex, racial, and ethnic subgroups, with results ranging from 83% to 92%. Vaccine effectiveness was higher against symptomatic COVID-19 (88%) than asymptomatic COVID-19 (73%).
From March to June 2021, 5,619 SARS-CoV-2 positive specimens were successfully sequenced. The most prevalent variants were alpha (42%), epsilon (18%), delta (12%), and gamma (9%), with delta increasing to 54% of variants by June 2021.
“This study adds to evidence of real-world Moderna COVID-19 vaccine effectiveness, particularly among the general population,” said Hung Fu Tseng, Ph.D., researcher with the Kaiser Permanente Southern California Department of Research & Evaluation and the senior author of the study.
In this study fully vaccinated patients are only followed throughout the period that overlapped with the emergence of the delta variant in the United States. Long-term follow-up is ongoing to further evaluate the durability of protection.
Source: Medindia
