COVID-19 vaccines highly effective against Delta variant, with Moderna leading way

INDIANAPOLIS, Ind. — The Delta variant of SARS-CoV-2 undoubtedly ranks as 2021’s most unwanted new arrival. On a positive note, however, a new study finds that the Pfizer, Moderna, and Johnson & Johnson vaccines are all effective at preventing both hospitalizations and serious cases of COVID-19 due to Delta variant infection.

Importantly, study authors note that the Moderna vaccine appears to be “significantly” more effective against the Delta variant than the other two vaccine options.

“These real-world data show that vaccines remain highly effective at reducing COVID-19 related hospitalizations and emergency department visits, even in the presence of the new COVID-19 variant,” says study author Shaun Grannis, M.D., M.S., Regenstrief Institute vice president for data and analytics and professor of medicine at Indiana University School of Medicine, in a media release. “We strongly recommend vaccinations for all who are eligible to reduce serious illness and ease the burden on our healthcare system.”

Researchers analyzed over 32,000 “medical encounters” across nine U.S. states occurring between July and August 2021 to reach these results. That process led to the conclusion that unvaccinated individuals who test positive for COVID-19 are five to seven times more likely to require emergency department care or hospitalization than vaccinated people.

Moderna shot provides most protection against Delta

More specifically, the Moderna vaccine was 95 percent effective at stopping hospitalizations among adults over the age of 18. Meanwhile, the Pzifer vaccine was 80 percent effective and the J&J vaccine was 60 percent effective.

The research team also reports that vaccine effectiveness, regardless of producer, is generally lower among those over 75 years-old. It is unclear as of now why this is the case.

Regarding the prevention of emergency department and urgent care visits, Moderna was 92 percent effective, Pfizer was 77 percent effective, and J&J was 65 percent effective.

“Despite the differences in effectiveness, vaccines continue to offer much more protection than not getting one at all,” Dr. Grannis concludes. “While breakthrough cases do happen, data shows the symptoms are less severe. The vast majority of COVID hospitalizations and deaths continue to be among unvaccinated individuals. COVID-19 vaccines are powerful tools for combating the pandemic.”

The findings appear in the CDC’s MMWR Morbidity and Mortality Weekly Report.