CDC ACIP meeting, September 22-23, 2021.
These estimates of vaccine effectiveness, broken down by age group, come from data on over 74,000 hospitalizations across 187 hospitals nationwide.
Here, we can see that Moderna has been outperforming Pfizer among adults ages 30-64. From June to August, Moderna's vaccine effectiveness against hospitalization was 99% in the 30-49 year old age group and 91% among 50-64 year olds. Pfizer's vaccine during that same time period was roughly 82% effective among 30-49 year olds, and 84% effective among 50-64 year olds.
But in younger adults, ages 18-29, the two vaccines performed almost identically, with vaccine effectiveness against hospitalization of 82% for Moderna and 85% for Pfizer.
It's tough to know exactly how the arrival of the Delta variant in the spring may be impacting how well vaccines work.