Study: Two doses of Pfizer Covid vaccine provides 95% protection

Two doses of the Pfizer-BioNTech vaccine are highly effective against COVID-19 infection, hospitalization and death, according to the first nationwide assessment in Israel.

The study, published in The Lancet medical journal, found that two doses of the vaccine provide more than 95% protection against infection, hospitalization, severe illness and death, including among the elderly.

While the findings are encouraging, several challenges to controlling the pandemic remain, it said.

Underlining that the duration of immunity to COVID-19 – both from infection and immunization – remains unknown, it said new vaccine-resistant variants could emerge in the future.

It went on to say that achieving herd immunity will require a continued increase of vaccination coverage worldwide.

The dominant COVID-19 strain during the study period was the B.1.1.7 variant. However, another prominent variant, B.1.351 – known as the South Africa variant – has recently been identified in Israel.

A single dose of the vaccine was associated with 58% protection against infection, 76% against hospitalization and 77% against death, it noted, emphasizing the importance of fully vaccinating adults.

By 14 days after vaccination, protection conferred by a second dose increased to 96.5% protection against infection, 98.0% against hospitalization and 98.1% against death, it said.

Protection among the elderly was as strong as that for younger people, with analysis indicating that people over 85 had 94.1% protection against infection, 96.9% against hospitalization and 97% against death seven days after receiving their second dose.

People aged 16-44 had 96.1% protection against infection, 98.1% against hospitalization and 100% against death, the study showed.

“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 Dr. Sharon Alroy-Preis, the lead author of the assessment.

“Until this point, no country in the world had described the national public health impact of a nationwide COVID-19 vaccination campaign. 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,” she added.

The authors used national pandemic surveillance data recorded by Israel’s Ministry of Health to produce the vaccine’s effectiveness. The data was analyzed in groups based on the participants’ age.

The average follow-up time for people who had received two doses was 48 days, the longest reported follow-up to date.

Since December 2019, the COVID-19 pandemic has claimed over 3.23 million lives in 192 countries and regions, according to figures compiled by US-based Johns Hopkins University.

Over 154 million cases have been reported worldwide, with recoveries now over 91 million.