New US studies released Friday show the COVID-19 vaccines remain highly effective against hospitalizations and death even as the extra-contagious delta variant swept the country. As delta surged in early summer, those who were unvaccinated were 4.5 times more likely than the fully vaccinated to get infected, over 10 times more likely to be hospitalized and 11 times more likely to die, according to the Centers for Disease Control and Prevention. CDC released two other studies Friday that signaled hints of waning protection for older adults. One examined COVID-19 hospitalizations in nine states over the summer and found protection for those 75 and older was 76 percent compared to 89 percent for all other adults. And in five Veterans Affairs Medical Centers, protection against COVID-19 hospitalizations was 95 percent among 18- to 64-year-olds compared to 80 percent among those 65 and older.