New York, Jan 28 : Drugmakers Pfizer and BioNTech have said that their Covid-19 vaccine has been found in laboratory studies to work against new variants first identified in the UK and South Africa. The results were published on the preprint server bioRxiv and submitted to a peer-reviewed journal. "While these findings do not indicate the need for a new vaccine to address the emerging variants, the companies are prepared to respond if a variant of SARS-CoV-2 demonstrates evidence of escaping immunity by the Covid-19 vaccine," Pfizer and BioNTech said in a statement on Wednesday. To study the effect of these mutations, three engineered viruses with key mutations were tested against the panel of human sera from 20 participants in the previously reported Phase 3 trial who had been immunized with the Pfizer-BioNTech COVID-19 vaccine. The sera from individuals vaccinated with the Pfizer-BioNTech Covid-19 vaccine neutralised all the SARS-CoV-2 strains tested, showed the study. Neutralisation against the virus with the three key mutations present in the South African variant was slightly lower when compared to neutralisation of virus containing the other mutations that were evaluated, the results showed. However, the the two companies believe the small differences in viral neutralisation observed in these studies are unlikely to lead to a significant reduction in the effectiveness of the vaccine. "Pfizer and BioNTech are encouraged by these early in vitro study findings and are currently evaluating the full set of mutations in the spike protein of the South African variant," the two companies said, adding that the flexibility of BioNTech's proprietary mRNA vaccine platform is well suited to develop new vaccine variants if required. Earlier this week, Moderna said that its two-dose regimen of the Covid-19 vaccine is expected to be protective against emerging strains detected to date Moderna said it is also working on a Covid-19 booster shot to protect against a new variant first identified in South Africa. A study carried by bioRxiv also showed that Covaxin, the Covid vaccine developed by Bharat Biotech in India, effectively neutralises UK variants of SARS-CoV-2 reducing the possibility of mutant virus escape. /IANS