Pfizer Vaccine Efficacy Drops as Delta Variant Spreads, According to Israel’s Health Ministry
Photo credit: Joel Saget, AFP via Getty Images
The Pfizer-BioNTech coronavirus vaccine’s efficiency dropped to 64% between early June to July, according to data from Israel’s Health Ministry. Comparatively, between May 2-June 5, its efficacy was reported to be 94%.
According to Haaretz, however, “experts have expressed doubt regarding the analysis of infection rates in Israel in recent weeks and the ministry’s epidemiology team has also questioned it.”
The drop in efficacy coincides with the spread of the Delta variant, as well as Israel’s lifting of Covid restrictions in June. The lifting of restrictions — including ending its vaccine passport system, capacity limits on gatherings, and the indoor mask mandate — has caused a slight uptick in cases.
As of July 4, Israel’s 7-day average of new covid cases was 297, compared to a rolling 7-day average of 16 new cases on June 3.
The uptick in cases, as well as the threat posed by the Delta variant, prompted Israel to reinstate its indoor mask mandate at the end of June and to consider reimposing the Green Pass system.
The vaccine is still 93% effective at preventing hospitalization and severe illness.
The ministry said Monday that it is not recommending a booster shot at this time, but that anyone who comes in contact with the virus — including those who are vaccinated — should get a Covid test.
Although the Delta variant has not appeared to be more deadly than other strains, it is believed to be far more contagious. A study by Public Health England suggests the variant is 60% more transmissible than the Alpha variant — which was already more contagious than the original strain that emerged from China.
The World Health Organization said in late June that the variant is on track to become the dominant Covid variant worldwide.
Israel’s announcement follows recent studies that have shown both Pfizer and Moderna’s efficacy against the Delta variant to be around 88%. Although less research has been done on the efficacy of the one-dose Johnson & Johnson/Janssen covid vaccine against the variant, the company announced last Thursday that preliminary research showed that it is more effective against the Delta variant than the Beta variant that came out of South Africa. Its vaccine is said to be 85% effective at preventing hospitalization from the variant.
