Unvaccinated people are 11 times more likely to die from COVID-19 than those who are fully vaccinated, new research has found, bolstering evidence that the inoculations continue to provide powerful protection, even against the delta variant.
The latest studies from the Centers for Disease Control and Prevention released on Friday also found that vaccinated people were nearly five times less likely to get infected and 10 times less likely to get so sick they ended up in the hospital.
The CDC "looked at COVID-19 cases, hospitalizations and deaths in 13 states and offers further evidence of the power of vaccination," Dr. Rochelle Walensky, director of the CDC, said at a White House COVID-19 briefing on Friday.
"As we have shown, study after study, vaccination works," she added.
However, the studies — which analyzed data from 600,000 Americans between April 4 and July 17 — suggest that the effectiveness of the vaccines may have dropped as the delta variant became dominant. One explanation could be waning immunity. A second is that the variant is better at evading the immune system. It also could be some combination of the two factors.
Another study examining data from nine states from June through August indicated that the Moderna vaccine may be the most effective of the three available in the United States.
The research found that across all ages, vaccine effectiveness was "significantly higher" among Moderna vaccine recipients — at 95% — than among Pfizer or Johnson & Johnson vaccine recipients, with vaccine effectiveness of 80% and 60%, respectively.
As of Friday, White House officials said nearly 75% of eligible Americans — those 12 and older — have gotten at least their first shot, and the CDC reported about 54% of the total population is fully vaccinated.
NPR's Rob Stein contributed to this report.