Britain could soon approve a fourth Covid-19 vaccine.
The latest serum has been developed by Novavax.
In trials it has proved to be 89% efficacious in preventing coronavirus.
Prime Minister Boris Johnson said Novavax will be assessed by the Medicines and Healthcare products Regulatory Agency (MHRA).
If approved, the vaccine could be ready by this summer.
The UK has already ordered 60 million doses.
They are being manufactured in Stockton-on-Tees.
Health Secretary Matt Hancock said:
“This is positive news and, if approved by the medicines regulator, the Novavax vaccine will be a significant boost to our vaccination programme and another weapon in our arsenal to beat this awful virus.”
Vaccines minister Nadhim Zahawi took part in the Novavax trials.
He said he was “particularly thrilled” to see such positive results.