GlaxoSmithKline has agreed in principle to handle the final part of manufacturing for up to 60 million doses of Novavax's Covid-19 vaccine for use in Britain.
GSK on Monday said that from May it would take on final production steps and bottling at its Barnard Castle plant in the north-east of England, without compromising supply of other vital medicine and vaccines.
A detailed agreement with the US biotechnology company Novavax and the UK government's vaccines taskforce has yet to be signed, it said.
Britain struck a deal to buy 60 million doses of Novavax’s vaccine candidate in August.
Novavax will make some of the vaccine using Fujifilm Diosynth Biotechnologies facilities in Stockton-on-Tees, northern England.
British Prime Minister, Boris Johnson on Monday said production there had started in anticipation of the vaccine's approval by the Medicines and Healthcare products Regulatory Agency.
Mr Johnson said the effort would provide 50 million to 60 million doses made in the UK.
Talks between Novavax and the EU over supply of up to 200 million doses have dragged on, with the US biotech company saying there had been shortages of raw materials.
GSK and partner Sanofi suffered a development setback in December.
But the British group has since agreed to collaborate on production and vaccine development with Germany's CureVac.
In a trial in Britain, Novavax's Covid-19 vaccine was this month shown to be 96 per cent effective in preventing cases caused by the original strain of the coronavirus.
The vaccine was also found to be 86 per cent effective in protecting against the more contagious B117 variant.
