The Pfizer-BioNTech COVID vaccine appears to largely prevent hospitalization and serious cases, but is significantly less effective against preventing the spread of the Delta variant of the coronavirus.
New Health Ministry figures reported by the Ynet news site indicated that over the past month, the vaccine, which has been the one used for almost all vaccinated Israelis, has been just 64 percent effective in preventing coronavirus infection. The data reportedly shows that during May, when the strain was less prevalent, the vaccine was 94.3% effective.
According to Ynet, the figures were presented Sunday evening at a meeting of a team of experts advising the government on its handling of the pandemic.
Meanwhile, a study from researchers at the Hebrew University and Hadassah University Medical Center indicated that the Pfizer vaccine is 60-80% effective against infection from the Delta strain.
The Delta variant, which is believed to be twice as contagious as the original strain of COVID-19, is thought to be responsible for 90% of new cases in Israel over the past two weeks.
The Health Ministry figures, however, report that the vaccine is still considerably effective against preventing serious symptoms and hospitalization. During May that figure stood at 98.2%, according to the data obtained by Ynet, and during June it was 93%.
But the researchers at Hebrew University warned that it was too early to fully tell how effective the vaccine is at preventing hospitalization.
“Due to the recognized delay in serious morbidity (by about 10 days), there is not currently enough data to predict how the current wave of infections will be expressed in serious cases,” wrote the researchers.
They added that while serious cases are expected to rise in the coming weeks, data from Singapore and the UK indicate that the Pfizer vaccine is still overwhelmingly effective at preventing the most serious symptoms.
The researchers urged the government to take immediate measures to halt the current rise in cases, including greater enforcement of the indoor mask mandate, boosting vaccination rates and the return of the “Green Pass” system, which limits access to some venues and events to only those who have been vaccinated or who have recovered from the illness.
Israel’s stockpile of Pfizer vaccines is slated to expire at the end of July, and it is working on several approaches to deal with the situation. The Prime Minister’s Office said on Sunday that Prime Minister Naftali Bennett has held several conversations in recent days with Pfizer CEO Albert Bourla to weigh bringing forward the date of the next shipment, or brokering a swap deal with another country for Israel’s expiring doses. Health Minister Nitzan Horowitz said Sunday evening that Israel was in advanced talks with another country on a swap deal.
Army Radio reported Monday morning that Israel is expected to begin using its Moderna stockpile once the Pfizer doses expire — just for those over age 18 — and is also considering giving a second dose of the Moderna vaccine to people who received a first dose from Pfizer, something already being done in Spain and Germany.
To that end, according to Army Radio, Israel has requested and received approval from Pfizer to delay its final decision on purchasing another 1 million doses from the company.
The coronavirus cabinet is slated to meet Tuesday evening to weigh a series of new restrictions amid the rise in new cases. The potential steps reportedly under consideration include the return of limits on large gatherings, the reinstatement of the Green Pass, and requiring vaccinated parents of infected children to quarantine until they receive a negative test.
As of Monday, there were 2,597 active cases in Israel after 343 people tested positive for COVID a day earlier.
There were 68 people hospitalized and 35 in serious condition. A week ago there were just 22 people in serious condition.