Pfizer said on Thursday that its Covid-19 vaccine blocked 94% of asymptomatic infections in an Israeli study – a result, CEO Albert Bourla called “extremely important”.
The study, which measured results two weeks after the second dose, also found that the vaccine was at least 97% effective against symptomatic cases of Covid, hospitalizations and deaths, according to Pfizer, which developed the BioNTech vaccine.
The analysis used data collected between January 17 and March 6, when the Pfizer vaccine was the only vaccine available in the country and when the more transmissible variant B.1.1.7 in the UK was the dominant strain.
“This is extremely important … for society,” Bourla said in an interview with CNBC’s “Squawk Box.” “Asymptomatic carriers and patients are the ones who spread the disease mainly. We expected something good in terms of symptoms,” he said, adding that the company did not expect such a “large number” against asymptomatic cases.
An asymptomatic person is someone who has Covid-19, but has no symptoms and never develops them. It is not the same as a pre-symptomatic patient who later develops symptoms. It is estimated that at least 50% of transmission occurred from asymptomatic people, according to a study published in January in JAMA.
The Israeli study means that the Pfizer vaccine could significantly reduce transmission.
“This clearly demonstrates the power of the COVID-19 vaccine to fight this virus and encourages us to continue our vaccination campaign even more intensively,” Israeli Health Ministry Director Yeheskel Levy said in a press release. . We aim to achieve even greater absorption in people of all ages, which gives us hope to regain normal economic and social function in the not-so-distant future. “
Israel launched its national vaccination campaign in December, giving priority to people over the age of 60, health workers and people with comorbid conditions. Until February, he led the world in vaccinations, inoculating millions of citizens against the virus.
In January, Pfizer and the Israeli Ministry of Health reached a collaboration agreement to monitor the real impact of its vaccine.
Bourla also said on Thursday that the company is assessing the impact that a booster dose can have on the virus, especially strain B.1.351 in South Africa, which it said “seems to be the toughest”.
“We already have very good two-dose protection,” he said.