Observational study finds mRNA vaccination is associated with an effectiveness of 85% against Covid-19 hospitalization.

Association Between mRNA Vaccination and COVID-19 Hospitalization and Disease Severity – JAMA

Editorial: Understanding Breakthrough Infections Following mRNA SARS-CoV-2 Vaccination – JAMA

Commentary: COVID-19 vaccines 85% effective against hospital cases but weaken over time – TCTMD

Related Study: Study compares the decline in effectiveness for Moderna, Pfizer, and Janssen vaccines and consequences for mortality.