The Wall Street Journal:
About half of adults infected in an outbreak of the Delta variant of Covid-19 in Israel were fully inoculated with the Pfizer Inc. vaccine, prompting the government to reimpose an indoor mask requirement and other measures to contain the highly transmissible strain.
Preliminary findings by Israeli health officials suggest about 90% of new infections were likely caused by the Delta variant, according to Ran Balicer, who leads an expert advisory panel on Covid-19 for the government. Children under 16, most of whom haven’t been vaccinated, accounted for about half of those infected, he said.
The government this week expanded its vaccination campaign to include all 12- to 15-year-olds after a jump in infections among schoolchildren in a town in central Israel. It has since quickly spread geographically and to other groups of the population.
The number of cases in Israel is relatively low by global standards. But new cases of Covid-19 rose to over 200 on Thursday from around 10 a day for most of June.
Israel is now reassessing its Covid-19 regulations after moving to open up its society and economy following multiple lockdowns last year.
“The entrance of the Delta variant has changed the transmission dynamics,” said Prof. Balicer, who is also the chief innovation officer for Israel’s largest health-management organization, Clalit.
The Delta variant, which first emerged in India in late 2020 and is also known as B.1.617.2, has now been detected in more than 70 countries. In the U.S., public-health experts expect it to soon become the dominant strain.
These so-called breakthrough cases—defined as positive Covid-19 test results received at least two weeks after patients receive their final vaccine dose—are broadly expected as the Pfizer vaccine is highly effective but not 100% foolproof, according to Mr. Balicer.
Israeli health officials are optimistic that even if the variant does spread, evidence from countries such as the U.K. indicate the vaccine will prevent a large increase in severe illness and hospitalizations that plagued the country’s health system in previous outbreaks. Israel has only recorded five severe cases in the past 10 days, Prof. Balicer said, but whether more will emerge is too early to tell.