new evidence reveals.
Compared with residents younger than 50 – so far vaccinated at lower rates than those of the higher-risk older people – Israelis 70 and older were 67% less likely to require mechanical ventilation for SARS-CoV-2 infection in February 2021 compared with October-December 2020.
“This study provides preliminary evidence at the population level for the reduction in risk for severe COVID-19, as manifested by need for mechanical ventilation, after vaccination with the Pfizer-BioNTech COVID-19 vaccine,” wrote lead author Ehud Rinott, department of public health, faculty of health sciences, Ben-Gurion University of the Negev in Beer-Sheva, Israel, and colleagues.
The study was published online Feb. 26, 2021, in Morbidity and Mortality Weekly Report.
The progress of COVID-19 vaccination across Israel presents researchers with a unique opportunity to study effectiveness on a population level. In this study, 84% of residents 70 and older received two-dose vaccinations. In contrast, only 10% of people in Israel younger than 50 received the same vaccine coverage.
Along with senior author Yair Lewis, MD, PhD, and coauthor Ilan Youngster, MD, Mr. Rinott compared mechanical ventilation rates between Oct. 2, 2020, and Feb. 9, 2021. They found that the ratio of people 70 and older compared with those younger than 50 requiring mechanical ventilation changed from 5.8:1 to 1.9:1 between these periods. This translates to the 67% decrease.
The study offers a “real-world” look at vaccination effectiveness, adding to more controlled evidence from clinical trials. “Achieving high vaccination coverage through intensive vaccination campaigns has the potential to substantially reduce COVID-19-associated morbidity and mortality,” the researchers wrote.
Israel started a national vaccination program on Dec. 20, 2020, targeting high-risk residents including people 60 and older, health care workers, and those with relevant comorbidities. At the same time, in addition to immunization, Israel has used strategies like stay-at-home orders, school closures, mask mandates, and more.
Potential limitations include a limited ability to account for the effect of the stay-at-home orders, spread of virus variants, and other concomitant factors; a potential for a delayed reporting of cases; and variability in mitigation measures by age group.
Dr. Youngster reported receipt of consulting fees from MyBiotix Ltd.
A version of this article first appeared on Medscape.com.