The Valneva Covid-19 vaccine, which is set to be made in Scotland, produces a strong immune response, the French company has said.
The UK funded several key trials of the vaccine and the results have been hailed by senior members of the government.
Data from an early-stage phase one/two study involving 153 people showed promising results for the jab, paving the way for the final phase three clinical trial.
The vaccine was safe and generally well tolerated, with no safety concerns identified by an independent data safety monitoring board.
The company said the results showed the vaccine was "highly immunogenic with more than 90% of all study participants developing significant levels of antibodies" to the Covid virus spike protein.
The vaccine also induced T-cell responses, which help the body fend off a virus and play a role in long-lasting immunity.
The vaccine is set to be produced in Livingston in Scotland if it gets approval.
The jab will still need a successful phase three trial before it can be approved by the UK regulator.
Two more jabs, produced by the US conglomerate Johnson & Johnson and US-based Novavax are close to getting their trials done so they can be accessed by regulators.
The UK has currently approved three Covid-19 vaccines, AstraZeneca, Pfizer and Moderna.
The Moderna vaccine will be in deployment “around the third week of April”, vaccines minister Nadhim Zahawi has confirmed and more jabs will come in May.
Prime Minister Boris Johnson said the findings were "very promising news" and the jab would be a "crucial weapon" against the disease providing it gained approval by regulators.
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"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.”
Health Secretary Matt Hancock said: "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."
Vaccines minister Nadhim Zahawi said: “These results are very promising and provide renewed hope that a vaccine using a whole inactivated virus might provide strong protection against variants.
“If the results from the phase three clinical trials are positive and the vaccine meets the robust standards of safety, quality and effectiveness of our medicines regulator, the MHRA (Medicines and Healthcare products Regulatory Agency), this will be another powerful weapon in our arsenal to beat this pandemic.”
Clive Dix, chairman of the Vaccines Taskforce, said: “These are great results from Valneva, particularly around the antibody and cellular responses generated and low numbers of adverse events, as these indicate good levels of immune responses among the participants to date.
“The findings of 100% levels of immunogenicity against the viral spike protein in the high-dose group is also encouraging.
“Inactivated virus vaccines are proven technologies that are often able to induce wide-ranging immune responses, and these promising data indicate that (Valneva) may continue this trend.”