The US Medicine and Health Products Regulatory Agency (MHRA) claims that the US vaccine is 89 percent effective in preventing coronavirus.
MHRA chief June Rhine said Novavax has received approval through testing and strict standardization.
UK Health Minister Sajid Javed said that British scientists are leading the world in the treatment of coronavirus.
Earlier on Monday, Australia approved the Novavax vaccine for people in Boston and above, and it is the fourth COVID-19 vaccine to be approved for use in the country after AstraZeneca, Mordana and Pfizer.
The Australian Technical Advisory Group on Immunization (ATAGI) recommends two doses of Novavax vaccination at least three weeks apart.