Poynter: Here’s what we really know about COVID-19 vaccine effectiveness
Poynter: Here’s what we really know about COVID-19 vaccine effectiveness. “If you don’t read any further, know this: No vaccine is 100% effective against any disease. The COVID shots are no exception. Effectiveness in preventing infection — defined as a positive test result — appears in some studies to wane sharply the more time that goes by after completing the one- or two-shot regimen. But on key measures — prevention of serious illness, hospitalization and death — real-world studies from the U.S. and abroad generally show protection weakening slightly, particularly in older or sicker people, but remaining strong overall, even with the rise of the more infectious delta variant of the COVID virus.