Israel reported on Monday a decrease in the effectiveness of the Pfizer/BioNTech COVID-19 vaccine in preventing infections and symptomatic illness but said it remained highly effective in preventing serious illness.
The decline coincided with the spread of the Delta variant and the end of social distancing restrictions in Israel.
Vaccine effectiveness in preventing both infection and symptomatic disease fell to 64% since June 6, the Health Ministry said. At the same time the vaccine was 93% effective in preventing hospitalizations and serious illness from the coronavirus.
The ministry in its statement did not say what the previous level was or provide any further details. However ministry officials published a report in May that two doses of Pfizer’s vaccine provided more than 95% protection against infection, hospitalization and severe illness.
A Pfizer spokesperson declined to comment on the data from Israel, but cited other research showing that antibodies elicited by the vaccine were still able to neutralize all tested variants, including Delta, albeit at reduced strength.