Despite being effective in preventing hospitalizations, Pfizer's vaccine was found only 39% effective in preventing the infection, according to researchers in Israel.
Israel's Health Ministry said on Friday that the Pfizer vaccine was found weak in preventing the COVID-19 infections due to delta variant but provided a strong shield against hospitalization and more severe forms of the virus.
The vaccine provided 88% protection against hospitalization and 91.4% against severe illness for an unspecified number of people studied between June 20 and July 17, the report from Israel's Health Ministry stated.
The delta variant first emerged in India and is spreading around the globe as governments race to inoculate people, sometimes infecting those already fully vaccinated against Covid. The mutation has forced some countries to delay or rethink plans to loosen curbs on businesses, activity, and travel.