Israel reported on Monday a decrease in the effectiveness of the Pfizer / BioNTech COVID-19 vaccine in preventing infections and symptomatic illnesses, but said it remains 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.
The vaccine’s 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 coronavirus.
The Ministry in its statement did not say what the previous level was or provide further details. However, Ministry officials released a report in May that two doses of Pfizer’s vaccine provided more than 95% protection against infections, hospitalizations and serious illnesses.
A Pfizer spokesperson declined to comment on the Israel data, but cited other research showing that antibodies elicited by the vaccine could still neutralize all tested variants, including Delta, albeit at reduced potency.
About 60% of Israel’s 9.3 million population have received at least one injection of the Pfizer vaccine in a campaign in which daily cases fell from more than 10 000 in January to single digits last month.
This prompted Israel to eliminate almost all social distancing, as well as the requirement to wear masks, although the latter was partially reimposed in recent days. At the same time, Delta, which has become a globally dominant variant of the coronavirus, began to spread.
Since then, daily cases have gradually increased, reaching 343 on Sunday. The number of seriously ill patients went from 21 to 35.
Data scientist Eran Segal from Israel’s Weizmann Institute of Science said the country was unlikely to experience the high levels of hospitalizations seen earlier in the year as there were far fewer critically ill patients.
He said it was okay to “continue life back to normal and unrestricted” while measures such as the scope of vaccination are stepped up and tests are secured for Israelis returning home from abroad.
