Two doses of the Pfizer-BioNTech COVID-19 vaccine provide a high level of protection for populations, a new study shows.
The findings from Israel — the first nation to report national data on the vaccine — show that two doses provide more than 95% protection for people 16 and older against COVID-19 infection, hospitalization and death.
The study period was from Jan. 24 to April 3, 2021, a time when the dominant strain in Israel was the B.1.1.7 variant first detected in the United Kingdom.
The found that two doses were key: A single dose of the vaccine provided only 58% protection against infection, 76% against hospitalization and 77% against death, the investigators found.
The differences between the effectiveness of one or two doses highlights the importance of fully vaccinating adults, according to the authors of the study published May 5 in The Lancet.
The findings also show the public health benefits of a national vaccination program, which was the key driver of a decline in COVID-19 infections in Israel.
“As the country with the highest proportion of its population vaccinated against COVID-19, Israel provides a unique real-world opportunity to determine the effectiveness of the vaccine and to observe wider effects of the vaccination program on public health,” said study author Sharon Alroy-Preis, from the Israel Ministry of Health.
“Until this point, no country in the world had described the national public health impact of a nationwide COVID-19 vaccination campaign,” she said in a journal news release. “These insights are hugely important because, while there are still some considerable challenges to overcome, they offer real hope that COVID-19 vaccination will eventually enable us to control the pandemic.”
Remaining challenges to controlling the pandemic include uncertainty about the duration of immunity from immunization and infection, the possible emergence of vaccine-resistant variants, and the need to increase vaccine coverage worldwide to reach global herd immunity, the researchers said.
The study findings “suggest that high vaccine coverage rates could offer a way out of the pandemic. Regrettably, rapid population-level coverage cannot be easily replicated in many other countries,” Eyal Leshem, a professor at the Chaim Sheba Medical Center in Israel, and Annelies Wilder-Smith, a professor in the London School of Hygiene & Tropical Medicine, wrote in an accompanying editorial.
The U.S. Centers for Disease Control and Prevention has more on COVID-19 vaccination.
SOURCE: The Lancet, news release, May 5, 2021