The antibodies created by the Pfizer jab may be around 40 times less effective against Omicron than the original Covid strain according to research by the Africa Health Research Institute.
The study included a small sample of people, only studying the blood of twelve patients who had received two Pfizer vaccinations.
This small report is believed to be the first evidence from laboratory test on the new variant since it began to spread across South Africa.
Omicron is thought to be five to ten times more likely to evade the jab than the Beta variant.
Professor Willem Hanekom, from the Africa Health Research Institute, said: “The clinical implications of these important laboratory data need to be determined.
“It is likely that lesser vaccine-induced protection against infection and disease would be the result.
“Importantly, most vaccinologists agree that the current vaccines will still protect against severe disease and death in the face of Omicron infection.”
There are currently just under 500 confirmed cases of the Omicron variant in the UK with 101 new cases being reported within the past 24 hours.
So far, the only restrictions put in place are that face masks are to be worn on public transport and in shops. The variant is yet to hospitalise or make anyone critically ill.
Michael Ryan, the World Health Organization’s emergencies director said: “We have highly effective vaccines that have proved effective against all the variants so far, in terms of severe disease and hospitalisation, and there’s no reason to expect that it wouldn’t be so.”