The Pfizer-BioNTech and Moderna vaccines being deployed to fight the coronavirus pandemic are highly effective in preventing hospitalizations among older adults, the group most at risk for severe disease and death, according to a federal study released Wednesday. …. In the study, fully vaccinated adults 65 and older were 94 percent less likely to be hospitalized with covid-19 than than unvaccinated people of the same age, according to the CDC. People who were partially vaccinated were 64 percent less likely to be hospitalized with the disease than the unvaccinated.