The potential clinical impact of implementing different COVID-19 boosters in fall 2022 in the United States.

With the emergence of new variants, key characteristics of the virus that affect estimates of spread and clinical impact also evolve, making parameter estimation difficult. Our analysis demonstrated that boosting with mRNA-1273.214 was more effective over 6 months in preventing infections and hospitalizations with a BA.4/5 subvariant than the tailored vaccine, simply because it could be deployed 2 months earlier. We conclude that there is no advantage to delay boosting until a more effective BA.4/5 vaccine is available; earlier boosting with mRNA-1273.214 will prevent the most infections and hospitalizations.