Study: COVID-19 vaccines remain effective against serious illness from Delta variant

A study published on Friday and co-authored by the HealthPartners Institute demonstrates that COVID-19 vaccines are remaining highly protective against serious illness from the Delta variant that requires urgent care, emergency room visits, or hospitalization, HealthPartners says.

The study was originally published in the CDC’s Morbidity and Mortality Weekly Report Thursday.

Researchers examined data from more than 30,000 urgent care visits, emergency room visits, and hospitals admission from June to August, when the Delta variant rose to the prominent strain of COVID-19 in the United States.

Researchers said vaccinated people required urgent care, emergency room visits or hospitalization in about the same proportion as prior to Delta being the dominant strain of COVID-19.

"People have been speculating about how effective COVID-19 vaccines are against the Delta variant and we now have evidence that suggests these vaccines are still very protective," said Malini DeSilva, MD, investigator with HealthPartners Institute and co-author on the study. "These vaccines remain the best way to prevent severe COVID-19, protect yourself, loved ones and community."

Additionally, research published in the New England Journal of Medicine on Wednesday from the same group of researchers examined COVID-19 data from January 1, 2021 to June 21, 2021, when Alpha was the dominant strain and found vaccines to be highly effective.