Israeli data suggests vaccine less effective against Delta variant — expert

Rising coronavirus cases in Israel offer “a preliminary signal” that the Pfizer-BioNTech vaccine may be less effective in preventing mild illness from the Delta variant, a top expert says.

But Ran Balicer, chairman of Israel’s national expert panel on COVID-19, stresses it is “too early to precisely assess vaccine effectiveness against the variant” first identified in India in April that is surging across the globe.

That is partly due to the overall low number of cases among fully vaccinated Israelis and because those cases are not evenly distributed across the population, further complicating efforts to reach conclusions about the data.

Rising transmissions suggest “some decrease in vaccine effectiveness against mild illness — but not severe illness — is likely.”

But, he adds, experts “remain hopeful that the vaccine effectiveness against serious illness will remain as high as it was for the Alpha strain” identified for the first time in Britain in December.