The odds of dying from COVID-19 are 90% lower for seniors who have received a third shot of the Pfizer-BioNTech vaccine at least five months after a second dose, a large study conducted during one country’s delta surge has found.
Investigators from Israel compared the mortality rate from COVID-19 between more than 700,000 booster shot recipients aged 50 years and older and their peers who did not receive a booster shot.
There were 65 deaths due to COVID-19 in the booster group and 137 among those in the non-boosted group. In addition, the number of confirmed SARS-CoV-2 infections was much higher in the group that hadn’t yet been boosted.
The evidence shows “significant life saving potential” of receiving a booster shot, and may help to resolve debate elsewhere about the need for boosters in adults under the age of 65 years, the researchers wrote in the New England Journal of Medicine.
Like other countries, Israel has seen evidence of waning vaccine effectiveness that has been particularly pronounced since the arrival of the delta variant. Booster shots are not currently mandated, but by the end of the study period, 90% of eligible older adults in the country had received a third shot of the Pfizer vaccine, Ronen Arbel, Ph.D., of Clalit Health Services, Tel Aviv, and colleagues said.
The study was limited by a relatively short time period of 54 days. “However, during this time, the incidence of COVID-19 in Israel was one of the highest in the world,” the researchers noted.