"From June to September 2021, 85% of COVID-19 hospitalizations were among those not fully vaccinated against COVID-19 and 15% were among fully vaccinated people. The share of COVID-19 hospitalizations among people not fully vaccinated was similar in June, July, August, and September 2021 (87%, 87%, 86% and 83%, respectively). The share of COVID-19 hospitalizations by vaccination status in Cosmos data is consistent with a recent CDC MMWR study of 13 jurisdictions, which similarly found fully vaccinated people were 14% of COVID-19 hospitalizations in the June-July period.
In the U.S., as of September 30, 2021, 56% of the population, 67% of the adults, and 83% of the elderly were fully vaccinated against COVID-19. People unvaccinated against COVID-19 make up a smaller share of the U.S. population (44%) but the vast majority (85%) of the hospitalizations with COVID-19."