The Covid-19 vaccine developed by Pfizer and BioNTech is expected to be up to 75 per cent effective against a coronavirus variant first detected in India.
BioNTech SE chief executive Ugur Sahin said on Thursday: "So far we've had the chance to test our vaccine against more than 30 variants of the virus. It has proven effective against mutations so far."
Tests this week have focused on the India variant, he said. "We expect (our vaccine) to protect against infections by 70 per cent to 75 per cent," said Mr Sahin, a German scientist with Turkish parents, speaking Turkish in televised comments.
Since the concerning Covid-19 variant, known as B16172, was first identified in India, it has ravaged that country and spread to at least 26 nations out of the 53 in the World Health Organisation's (WHO) European Region, the organisation said.
The WHO's regional director said on Thursday Covid-19 vaccines being deployed in Europe, including the Pfizer/BioNTech shot, appear able to protect against circulating virus variants that have caused concern because they are more easily transmitted.
Mr Sahin was speaking with Turkish Health Minister Fehrettin Koca, who separately said the country recorded less than 10,000 daily new coronavirus cases for the first time since March 1st.
Turkey, which briefly was second globally last month in new infections, is using the Pfizer/BioNTech vaccine as well as China's Sinovac Biotech shot in its vaccination program.
A BioNTech spokeswoman said lab tests show that when the blood of vaccinated people is exposed to the Indian variant, 25 per cent to 30 per cent fewer antibodies were binding to the virus than would have been the case with the original coronavirus.
That suggests protection against the variant, whether symptomatic or not, is a bit lower but still 70 per cent to 75 per cent.
It is about 95 per cent effective against the original version of the virus.