NEW YORK Three studies published on Friday provided additional evidence that COVID-19 vaccines are effective against the omicron variant, at least in those who received booster shots.
They are the first large-scale studies in the United States to examine vaccine protection against omicron, according to health officials.
The papers confirm previous research (including studies conducted in Germany, South Africa, and the United Kingdom ) indicating that available vaccines are less effective against omicron than older coronavirus strains, but also that booster doses boost virus-fighting antibodies, increasing the likelihood of avoiding symptomatic infection. From August to this month, the first study examined hospitalizations and emergency room and urgent care centre visits in ten states.
It discovered that three doses of the Pfizer or Moderna vaccines were most effective at preventing COVID-19-associated emergency department and urgent care visits. Protection decreased from 94 percent to 82 percent during the delta wave. Two doses provided less protection, particularly if six months had passed since the second dose.
The second study examined COVID-19 case and death rates in 25 states from April to December. Individuals who were boosted had the best protection against coronavirus infection, both during the delta era and also during the omicron era.