Pfizer COVID-19 vaccine only 39% effective against Delta variant, claims Israel study

Two doses of the Pfizer-BioNTech vaccine are only 39 percent effective in preventing infection and symptomatic illness caused by the Delta variant of coronavirus, Israeli officials said on July 22. The percentage was scaled down from the estimated 64 percent two weeks ago to 39 percent by Israel’s Health Ministry.

Meanwhile, Johnson & Johnson vaccine was found to be 33 percent effective against the Delta variant.

The Israel Health Ministry said the Pfizer vaccine is still effective and provides high levels of protection against hospitalization at 92 percent and severe illness at 91 percent for patients who have tested positive for the Delta variant.

The revised efficacy percentage is based on recent data collected from an unspecified number of people between June 20 and July 17, according to reports. In the initial clinical trials, the Pfizer vaccine’s efficacy against other variants was found to be 95 percent.

Reports by Public Health England and others, however, suggest that there is only slight decrease when it comes to protection against infection and illness when compared to Israel’s findings.

A joint statement by Pfizer and BioNTech based on the health ministry’s statement said, though real-world data from Israel shows there is a decline in vaccine efficacy six months post-vaccination against infection and symptomatic disease, “efficacy in preventing serious illnesses remains high.”

Dr Isaac Bogoch, Infectious Disease Professor at the University of Toronto, told CNBC, the shots are still effective in preventing severe infections and hospitalization, and “we’re still in the COVID era and anything can happen,”.

Meanwhile, the Delta variant has spread to over 100 countries.

The US is seeing infections in fully vaccinated people. White House chief medical officer Dr Anthony Fauci has recommended fully vaccinated people consider wearing masks indoors as the virus is capable of transmitting from person to person.

Pfizer, witnessing a decrease in its two-dose vaccine efficacy, remained cautious and sought authorisation from the Food and Drug Administration for a booster dose, which has been denied by officials.