Israel has reportedly seen a steep decline in the efficacy of the Pfizer vaccine in preventing COVID-19 infections as the Delta variant expands its reach. 

Israeli media outlet Ynet said on Monday, citing data from the Israeli Health Ministry, the vaccine had a 64 percent efficacy rate between June 6 and July 3, as opposed to the 94-point-three percent recorded between May 2 and June 5. 

The outlet said it was attributed to a spike in cases involving the Delta strain, as well as the easing of government restrictions on June 1. According to Israeli daily Haaretz, around 90 percent of recent COVID-19 infections involved the Delta variant. 

The change in the vaccine’s efficacy in preventing hospitalization and serious illness, on the other hand, was relatively small in the cited period from 98-point-two percent to 93 percent, Ynet said.