(CNN Español) — The booster dose of the Pfizer / BioNTech coronavirus vaccine reduced COVID-19 infections and deaths by 90% tenfold, two separate studies from Israel show.
The two studies, published in The New England Journal of Medicine, analyze the effects of Israel’s campaign that offered booster vaccines to all people over 12 years of age in the face of the spread of the delta variant during the summer. While deaths and severe cases were low among fully vaccinated people, booster shots dramatically reduced them.
Ron Milo and his colleagues at the Weizmann Institute of Science analyzed data from five million people over the age of 16 and compared those who received a booster dose of the Pfizer / BioNTech vaccine 12 days or more before with those who did not receive a booster. . “The confirmed infection rate was lower in the booster group than in the no-boost group by a factor of approximately 10,” they wrote. “Among those aged 60 and over, mortality was lower by a factor of 14.7,” they added.
“In all age groups studied, the rates of confirmed COVID-19 and severe disease were substantially lower among those who received a boosted dose of BNT162b2 vaccine than among those who did not.”
Clalit Health Services’ Dr. Shlomit Yaron and his colleagues looked at all members of the health services group who were 50 years of age or older who had received two doses of the Pfizer / BioNTech vaccine at least five months earlier. During August and September, 65 people who received reinforcements died and 137 people who did not receive reinforcements died. “Participants who received a booster at least five months after a second dose of BNT162b2 had 90% lower mortality due to COVID-19 than participants who did not receive a booster,” the team wrote.
“The data from both studies indicated a relative effectiveness against serious illness or death of 90 to 95%. This means that if the absolute effectiveness of two doses of vaccine is 90%, the absolute effectiveness of two doses plus a booster is 99 to 100%, “said Dr. Minal Patel of the International Special Commission on the Coronavirus of the United States. US Centers for Disease Control and Prevention.
“Therefore, it is important that vaccination with the primary series, especially in high-risk populations, remains a top priority everywhere, because this will ultimately lead to a further reduction in serious diseases and deaths.”
That said, Patel added, it’s even more important to make sure people who haven’t been vaccinated get vaccinated first.
