“Examining numerous cohorts through the end of July and early August, three points are now very clear,” CDC director Rochelle Walensky said at a White House covid-19 news briefing Wednesday. “First, vaccine-induced protection against SARS-CoV-2 infection begins to decrease over time. Second, vaccine effectiveness against severe disease, hospitalization and death remains relatively high. And third, vaccine effectiveness is generally decreased against the delta variant.”
