An early look at the performance of COVID-19 booster shots during the recent Omicron wave in the U.S. showed a decline in effectiveness against severe cases, though the shots still offered strong protection.
The report, published by the U.S. Centers for Disease Control and Prevention on Friday, is considered an early and limited look at the durability of booster protection during the Omicron surge that exploded in December and January but has been fading in recent weeks.
The researchers looked at patient visits to hospitals and urgent care centres in 10 states. They estimated how well the booster prevented COVID-related
