Drew Weissman of the Perelman School of Medicine said the COVID-19 vaccines are “still working great,” but highly contagious variants and low vaccination rates are eroding progress. “You can’t control a pandemic when 30 percent or even half the people are immunized,” he said.
https://www.pbs.org/newshour/health/breakthrough-covid-infections-show-the-unvaccinated-are-now-putting-the-vaccinated-at-risk The New York Times