New data from the UK Health Security Agency indicate that booster shot protection against symptomatic COVID-19 caused by the Omicron variant fades within 10 weeks or so. There’s no indication as to whether that means boosters are any more or less successful at preventing severe disease in those who do become infected with the Omicron variant of the virus. The research shows that providing two doses of the AstraZeneca vaccine (available in the UK but not in the U.S.) followed by a booster with the Pfizer or Moderna vaccine was 60% effective at preventing symptomatic disease 2 to 4 weeks after the initial immunization cycle was complete. After 10 weeks, however, the Pfizer booster dropped to 35% effectiveness, while the Moderna booster was 45% effective. The data were drawn from 148,000 Delta cases and 68,000 Omicron cases in the UK.
Be Aware: Booster Protection Against Omicron Doesn’t Last as Long as We Might Hope