Pfizer, BioNTech say Israeli data suggests vaccine greatly reduces asymptomatic infections
Findings not yet peer-reviewed, interaction of vaccine with B1351 variant unclear due to limited data
Pfizer Inc and BioNTech said on Wednesday that real-world data from Israel suggests their coronavirus vaccine is 94 per cent effective in preventing asymptomatic infections, meaning it could significantly reduce transmission.
The companies also said the latest analysis of the Israeli data shows the vaccine was 97 per cent effective in preventing symptomatic disease, severe disease and death. That is basically in line with the 95 per cent efficacy Pfizer and BioNTech reported from the vaccine's late-stage clinical trial in December.
Israel's Health Ministry, which has been sending data to Pfizer and is working with the health-care providers giving the vaccine, did not respond to requests for comment.
The analysis also shows real-world evidence of the vaccine's effectiveness against a highly infectious variant of the coronavirus first discovered in Britain, known as B117. More than 80 per cent of the tested specimens when the analysis was conducted were variant B117.
There were only a limited number of infections in Israel caused by the variant first discovered in South Africa — known as B1351 — so they were not able to evaluate effectiveness against this variant.
Significant declines in deaths, cases recently
In terms of population covered, Israel is leading the world in its vaccination program, thanks in part to an agreement to share data with Pfizer and BioNTech.
As of Wednesday, around 55 per cent of Israel's population of nine million had been given at least one dose of the Pfizer-BioNTech COVID-19 vaccine, according to Health Ministry data, and 43 per cent have received both doses.
Since the mid-January peak, Israel has seen 71 per cent fewer COVID-19 deaths, 55 per cent fewer cases, 45 per cent fewer new critically ill patients and 40 per cent fewer critically ill patients in hospitals, according to Eran Segal, a data scientist at the Weizmann Institute of Science.
On Wednesday, 2,802 Israelis tested positive — or 2.9 per cent from nearly 99,000 tests.
According to the analysis, unvaccinated individuals were 44 times more likely to develop symptomatic COVID-19 and 29 times more likely to die from COVID-19 than those who had received the vaccine.
The data, collected from Jan. 17 to March 6, has not yet been peer reviewed.
WATCH | A deeper dive into Israel's vaccination program:
Israel's Health Ministry previously found that the Pfizer vaccine developed with Germany's BioNTech reduces infection, including in asymptomatic cases, by 89.4 per cent and in symptomatic cases by 93.7 per cent. That was in data collected from Jan. 17 to Feb. 6.
Pfizer did not provide further details on its analysis of asymptomatic infections. In a previous unpublished study by the Health Ministry and Pfizer, Israeli researchers said further study was needed on asymptomatic transmission among people fully vaccinated because they are less likely in Israel to be tested for COVID-19.
