FRANKFURT (REUTERS) - BioNTech and Pfizer said on Wednesday (Dec 8) that a three-shot course of their Covid-19 vaccine was able to neutralise the new Omicron variant in a laboratory test, and they could deliver an Omicron-based vaccine in March 2022 if needed.

In the first official statement from vaccine manufacturers on the likely efficacy of their shot against Omicron, BioNTech and Pfizer said two vaccine doses resulted in significantly lower neutralising antibodies, but a third dose of their vaccine increased the neutralising antibodies by a factor of 25.

Blood obtained from people that had their third booster shot a month ago neutralised the Omicron variant about as effectively as blood after two doses fought off the original virus first detected in China.

"Ensuring as many people as possible are fully vaccinated with the first two-dose series and a booster remains the best course of action to prevent the spread of Covid-19," Pfizer boss Albert Bourla said in the statement.

The findings are broadly in line with a preliminary study published by researchers at the Africa Health Research Institute in South Africa on Tuesday, saying that Omicron can partially evade protection from two doses of the Pfizer-BioNTech vaccine, suggesting also that a third shot might help fend off infection.

A lab analysis at the university hospital of Frankfurt in Germany, however, found a reduced antibody response to Omicron even after three shots.

An executive with German drugmaker BioNTech on Wednesday said the interval between the second and third dose of its Covid-19 vaccine can be reduced to at least three months to enable better protection against the Omicron variant in the winter season.

Chief Executive Officer Ugur Sahin said new data would prompt a discussion about bringing the third shot of its currently available vaccine forward.

"We believe this is the right way to go," he said. "It is very clear that our vaccine for the Omicron variant should be a three-dose vaccine," he added during a press call.