Pfizer jabs only partially effective against Omicron; booster shots required: Study

The Omicron variant, which is known to have more mutations than Delta, can partially evade protection from two doses of Pfizer-BioNTech’s COVID-19 vaccine, said the research head of a laboratory at the Africa Health Research Insitute in South Africa on Tuesday. But the study also revealed that the blood from samples who had received both doses of the Pfizer vaccine and also suffered a prior infection of COronavirs infection was mostly able to neutralise the B.1.1.529 variant. This further indicates that booster doses of the same vaccine could be of help to prevent infection from the Omicron variant. 

The latest variant of SARS-CoV-2, Omicron was detected first by South African scientists before they alerted the mutation to the World Health Organization (WHO) on 24 November. On 26 November, the United Nations (UN) health agency designated Omicron as a “variant of concern” and now it has been detected in more than 40 nations. Scientists have previously revealed that Omicron has the most number of mutations than any previous strains and is also known to be spreading three times the speed of previous variants. 

Now, Alex Sigal, a professor at the research institute said on Twitter that there was “a very large drop” in the immunity against the Omicron variant relative to an earlier strain of the Novel Coronavirus. He described that two doses of Pfizer-BioNTech COVID-19 vaccine showed around the 41-fold decline in the protection against the new COVID variant. Notably, the first laboratory experiments on new variants have been welcomed as “better than expected”. 

Boosters to increase protection against Omicron

As drugmakers across the globe continue to scramble efforts to test their respective vaccines’ efficacy against Omicron, a small study was led by Sigal who is a professor at the Africa Health Research Institute, in South Africa. The study is yet to be peer-reviewed, but it has suggested that booster shots could be efficient against the new Coronavirus variant. Despite the 41-fold decline in levels of immunisation against Omicron, “the previous infection, followed by vaccination or booster is likely to increase the neutralisation level and likely confer protection from severe disease in omicron infection,” said Sigal. 

It is pertinent to note that Sigal’s laboratory studied the blood samples of 12 people vaccinated with the Pfizer jab. It was found that five out of six cases those who had been vaccinated and were also previously infected with COVID-19 were able to neutralise the Omicron variant. AHRI professor hailed the findings and said that results showed that the “more antibodies you got, the more chance you'll be protected from Omicron.”

(IMAGE: Unsplash/Twitter)