Pfizer-BioNTech say data suggests COVID-19 vaccine 94% effective in preventing asymptomatic infection
NEW YORK/JERUSALEM: Pfizer and BioNTech said on Thursday (Mar 11) that real-world data from Israel suggests their COVID-19 vaccine is 94 per cent effective in preventing asymptomatic infections, suggesting it could significantly reduce virus 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 in line with the 95 per cent efficacy reported in the vaccine's late-stage clinical trial in December.
Israel's Health Ministry, which is working with the healthcare providers administering the vaccine, said in an emailed statement that the data was developed from the ministry's tracking of morbidity.
Israel’s Health Ministry previously found that the Pfizer-BioNTech vaccine reduces infection, including in asymptomatic cases, by 89.4 per cent and in symptomatic cases by 93.7 per cent. That was from data collected from Jan 17 to Feb 6.
Pfizer Chief Executive Albert Bourla said the data was important for society because it means fewer people are passing on the virus to others without knowing it. The company plans to publish the data in a peer reviewed journal, he said.
The analysis also shows real-world evidence of the vaccine's effectiveness against a highly infectious variant of COVID-19 first discovered in Britain, known as B117. More than 80 per cent of the tested specimens were that variant.
There was no evaluation of its effectiveness against the virus variant first discovered in South African known as B1351 due to the limited number of infections with that variant in Israel.
As of Wednesday, around 55 per cent of Israel's 9 million population 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.
According to the analysis of data collected from Jan 17 to Mar 6, unvaccinated individuals were 44 times more likely to develop symptomatic COVID-19 and 29 times more likely to die from the illness.
In a previous unpublished study by the health ministry and Pfizer, Israeli researchers said further study was needed on asymptomatic transmission among fully vaccinated people because they are less likely in Israel to be tested for COVID-19.
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.