The vaccine, which is being made at Valneva’s Livingston site in West Lothian, was “well tolerated” in phase one and two clinical trials and no safety concerns have been raised.
More than 90 per cent of participants produced “significant” levels of antibodies to the virus, and the vaccine also induced T-cell responses, which help the body fend off a virus and play a role in long-lasting immunity.
The study involved 153 healthy adults aged between 18 and 55.
The next stage is a phase three clinical trial, which Valneva hopes to begin by the end of April. The vaccine is then expected to be submitted to the Medicines and Healthcare products Regulatory Agency (MHRA) in the Autumn.
The UK has ordered 100 million doses of the vaccine, of which a proportion will be delivered to Scotland
Thomas Lingelbach, Valneva chief executive, said: “We are extremely pleased with these results which take us a step closer to providing an inactivated vaccine to help the global fight against Covid-19.
"The world needs multiple vaccines as well as booster options. Given the potential advantages often associated with inactivated whole virus vaccines, we believe that VLA2001 has an important role to play.
"This includes potential modifications to the vaccine to address variants, using our existing manufacturing process. I want to thank everyone involved in the ongoing work. We could not have achieved this milestone without them.”
UK Health Secretary Matt Hancock said: “The UK government has funded these clinical trials and it is fantastic to see Valneva’s vaccine produces a strong immune response.
"This vaccine will be made onshore in Livingston in Scotland, giving another boost to British life science, and if approved will play an important role in protecting our communities. I look forward to seeing the results of the upcoming phase three trial.”
It is expected that the Covid-19 vaccine will be manufactured in Livingston for some years to come, providing regular vaccines in a similar way to those given for flu.
It is an inactivated whole virus vaccine, a more “traditional approach” than other Covid-19 vaccine manufacturing methods, and may be particularly suitable for those with weaker immune systems.
Asked who the Valneva vaccine might be given to in Scotland, First Minister Nicola Sturgeon said future rounds of vaccination are currently being considered by the Scottish Government, but details have yet to be decided.