Pfizer effective against Omicron: Israeli study

A limited study conducted by the Sheba Medical Center and the Israeli Health Ministry's Central Virology Laboratory has produced encouraging results regarding the effectiveness of the Pfizer-BioNtech Covid-19 vaccine on the new and mutated Omicron variant. Patients who received three doses of the vaccine were more likely to be protected against infection and severe infection from Covid-19, the study concluded.

The study also concluded that while a booster dose increase neutralization effect, the protection afforded against Omicron was four times lower than the vaccine's protective ability against the Delta strain.

This may bolster Pfizer's own research Presenred on Wednesday, which has also suggested that three doses of the vaccine afford 'significant protection' against the virus.

Israeli scientists compared the blood of 20 people who had received two vaccine doses 5-6 months earlier to the same number of individuals who had received a booster a month before. Gili Regev-Yochay, director of the Infectious Diseases Unit at Sheba, told reporters that those who had received two doses 5-6 months ago were protected against the Delta strain but not Omicron. However, with a booster dose, the neutralization effect of the vaccine increased almost hundred fold, he was quoted as saying by Reuters.

The Israeli team said they worked with the actual virus while the companies used what is known as a pseudovirus, which was bio-engineered to have the hallmark mutations of Omicron. The Israeli research follows a study from South Africa that found the Omicron variant can partially evade protection from two doses.

"The first line of defence, with two doses of vaccination, might be compromised and three doses of vaccination are required to restore protection," BioNTech Chief Medical Officer Ozlem Tuereci said at a press conference. The companies also said they could deliver an upgraded vaccine targeted specifically at the Omicron variant in March 2022 if one is needed.

While the Omicron variants emergence has sparked alarm due to the high number of mutations associated with its 'spike proteins' which help it enter human cells, reports of the virus' lethality and severity have so far suggested that it causes comparatively milder cases than the Delta strain. However the virus may be more transmissible and likely to cause 'breakthrough infections' in the fully-vaccinated according to scientists.