Pfizer vaccine less effective against delta variant

A study in Israel found that the Pfizer COVID-19 vaccine is somewhat less effective against the more infectious delta variant, although it has always been shown to be effective in preventing serious illness.

As reported by the Wall Street Journal, Pfizer’s vaccine protected 64 percent of people immune to a delta-variant outbreak, a steep drop from the 94 percent of people it had previously proven to protect. However, the vaccine was still 94 percent effective in preventing serious illness, a slight decrease from the 97 percent who had been prevented from suffering from serious illness previously.

Data for the study was collected from June 6 to early July, according to officials from Israel’s health ministry. Data and study methodology have not been published, according to the Journal.

Some health experts have expressed skepticism about the Israeli study, saying mRNA vaccines like Pfizer have been shown to offer strong protection against COVID-19 infection.

“Speaking to colleagues in Israel, it is a real skepticism about the 64% number,” wrote Dean Ashish Jha of the Faculty of Public Health at Brown University on Twitter. “The best data still suggest that mRNA vaccines offer a high degree of protection against infection.”

“And great protection against serious illness,” Jha added. “Let’s wait for more data, but from now on, if you’re vaccinated, I wouldn’t worry.”

Jha clarified that he was not saying the study results were incorrect, but pointed out that most of the data suggested a high rate of effectiveness in protecting against the delta variant, pointing to a UK study that found that ‘it was 90% effective.

To be clear, not saying 64% is definitely wrong

But UK data says almost 90% against infections,> 90% against serious illnesses

So we’ll see occasional data points that don’t match

May turn out to be right

But at the moment, much of the evidence points to the vaccines working very well against Delta.

– Ashish K. Jha, MD, MPH (@ashishkjha) July 5, 2021

The Journal noted that the results of this study were released as Israel is currently experiencing a slight increase in the number of new cases, with experts finding that 90% of new cases were likely caused by the delta variant. Despite this increase, the number of cases in Israel still remains low by global standards.

More than 80 percent of Israel’s adult population has been fully immunized with two doses of the Pfizer vaccine, the Journal reports.