Data on vaccine efficacy against infection!

https://www.cdc.gov/mmwr/volumes/70/wr/pdfs/mm7034e3-H.pdf

We have a lot of data on the (outstanding!) vaccine efficacy at protecting against hospitalization and death from COVID-19, but good data on efficacy against infection is harder to come by.

Here's a paper in the MMWR that examines efficacy against infection for three different time periods, the most recent of which is while Delta was the dominant strain in the population.

This data is from nursing home residents (i.e., the elderly), so protection against infection among the general populace is potentially somewhat better.

TL;DR: In a nursing home setting, the SARS-CoV-2 vaccines appear to offer a 50% reduction in the rate of infection. (Along with, of course, a protection against hospitalization or death in the 90% range)