Pfizer said Thursday that its Covid-19 vaccine blocked 94% of asymptomatic infections in an Israeli study, a result that CEO Albert Bourla considered “extremely important.”
The study, which measured results two weeks after the second dose, also found the vaccine was at least 97% effective against symptomatic cases of Covid, hospitalizations and deaths, according to Pfizer, which developed the shot with BioNTech.
The analysis used data collected between January 17 and March 6, when the Pfizer vaccine was the only trait available in the country and when the most 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”. “Carriers and asymptomatic patients are the ones who spread the disease mainly. We were expecting something good in terms of symptomatology,” he said, adding that the company did not expect a “high number” against asymptomatic cases.
An asymptomatic person is someone who has Covid-19 but has no symptoms and never develops it. It is not the same as a pre-symptomatic patient who then develops symptoms. According to a study published in January in the JAMA, it is estimated that at least 50% of transmission has occurred from asymptomatic people.
The Israeli study means 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 even more intensely with our vaccination campaign,” Israeli Health Ministry Director Yeheskel Levy said in a statement. of press. Our goal is to achieve even greater participation in people of all ages, which gives us hope to regain normal economic and social function in the not-too-distant future. “
Israel launched its national vaccination campaign in December, prioritizing people aged 60 and over, health workers and people with comorbid conditions. In February, it was a world leader in vaccinations, inoculating millions of citizens against the virus.
In January, Pfizer and the Israeli Ministry of Health signed a collaboration agreement to monitor the real-world impact of their vaccine.
Bourla also said Thursday that the company is assessing the impact a booster dose may have on the virus, particularly strain B.1.351 in South Africa, which it said “seems to be the toughest”.
“We already have very good protection with two doses,” he said.