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19th Jan 2022

Fourth Pfizer jab ineffective in blocking Omicron, according to Israeli study

Kieran Galpin


The level of antibodies needed to fight Omicron was ‘probably too high for the vaccine to produce’

A fourth Pfizer vaccine is mostly ineffective in halting Omicron infections despite empowering antibodies, a study from Israel has revealed.

Healthcare professions at the Sheba Medical Center in Israel continued to get infected despite having four doses of the BioNTech/Pfizer vaccine. Blood work did show an increase in antibodies, said research lead professor Gili Regev-Yochay.

In order to track the vaccine’s efficiency, thousands of Sheba employees have undergone regular serology tests that started before their first dose in December 2020, reports the Financial Times.

Researchers found that despite four jabs, the level of antibodies needed to fight Omicron was “probably too high” for the vaccine to produce, said Regev-Yochay.


While the study is yet to be peer-reviewed, the initial findings were shared with government bodies. The study highlighted that the fourth shot was less productive than the third, which was more effective than the second jab.

Regev-Yochay said, “the decision to allow the fourth vaccine to vulnerable populations is probably correct”, but it did not show results to support giving “it to all of the population”.

This comes as Boris Johnson is expected to make an announcement today regarding the ‘Plan B’ restrictions still in place.

According to the BBC, a spokeswoman for the government said the decision was a “finely balanced” one, though did add that the latest data was “encouraging”. According to the Guardian, a senior source within Number 10 claimed they were looking to end the mandatory self-isolation period for those who test positive.

“There’s a few legal powers still on the statute book, not least the requirement to self-isolate. At some point we will have to address them,” the source claimed.

A further two sources said covid passports and working from home were “unlikely to continue” past January 26, with mask mandates still in effect. It is also likely that Number 10 will lift covid testing for those citizens returning from abroad.

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