The BioNTech/Pfizer vaccine is less effective in halting the spread of the Delta variant than that of previous strains of coronavirus, according to a preliminary study by Israel’s health ministry.
Data collected over the past month suggest the vaccine is 64 per cent effective at preventing infection among those who are fully inoculated, the ministry has found. Efficacy against previous strains of the virus was estimated at 94 per cent.
However, the figures, first reported in the Ynet news portal, indicate the vaccine is 93 per cent effective against serious illness and hospitalisation.
The study is based on “preliminary” figures relating to the effectiveness of the vaccine gathered by health authorities continuously, cautioned Professor Nadav Davidovitch, who sits on the government’s expert advisory committee on Covid-19.
“Delta is a lot more infectious, but appears to not lead to as much serious illness and death, especially given that we now have the vaccine,” he said.
Cases have ticked up since Israel lifted all remaining Covid-19 restrictions on June 1, with many experts blaming the highly transmissible Delta variant.
As of Monday the country had nearly 2,600 active cases — more than double that of the previous week — though the ministry said only 35 were considered seriously ill.
Earlier this year British health authorities also documented a drop in efficacy for the Pfizer jab versus the Delta variant, though less severe. Public Health England in May found the vaccine provided 88 per cent protection against symptomatic infection with Delta, and 93 per cent against the Alpha variant first identified in Kent. According to that study, the protection conferred by two doses of the Oxford/AstraZeneca vaccine — largely used in the UK’s mass vaccination — was lower, at 66 per cent for the Delta variant.
Israel has enjoyed one of the world’s fastest inoculation drives, emerging from lockdown in the spring. More than 5m of Israel’s 9m citizens have been fully vaccinated with the Pfizer vaccine.
But rising case rates have alarmed the government of Naftali Bennett. The government last month reimposed face mask requirements for indoor gatherings and public transport and is considering additional restrictions, including the reintroduction of the “green passport” scheme for those who have been vaccinated, limits on large public gatherings and “booster” jabs.
A push to inoculate teenagers, including the prime minister’s daughter, began last week and more than 100,000 have received a jab.
Israel’s reaction to a surge in Delta infections stands in contrast with that of the UK, where prime minister Boris Johnson is planning to lift all restrictions on July 19.
“If the numbers continue to grow, now doubling every week, we need to vaccinate as quickly as possible the roughly million people still left — 200,000 over 50 years of age, and of course children,” Prof Davidovitch said. “The government will also likely introduce elements of the Green Pass scheme, mandatory mask wearing, lots of testing, and stricter oversight for all incoming passengers at Ben Gurion international airport.”
“I don’t believe it will be like the UK,” he added. “We have more vaccinated people here, Pfizer seems to provide better defence than (AstraZeneca), and I don’t believe the government will allow the virus to run rampant. We have to be proportional in our response.”