The European Medicines Agency (EMA) started a rolling review on Friday of a variant-adapted Covid-19 vaccine from Moderna, as coronavirus cases linked to Omicron sub-variants see an uptick in the region.
US-based Moderna's so-called bivalent vaccine targets two strains of the SARS-CoV-2 virus behind Covid, the original strain first identified in China, and the Omicron variant.
Last week, Moderna said its bivalent vaccine produced a better immune response against Omicron than the original shot.
On Wednesday, the EMA also launched a rolling review of a competing mRNA variant-adapted vaccine made by the partnership between Pfizer and BioNTech.
A rolling review means the regulator assesses the data as it becomes available, and the process continues until there is enough data for a formal marketing application.
While a new Omicron-driven wave of infections has been widely anticipated in the northern hemisphere this autumn and winter, a European disease monitoring agency has already warned cases could surge soon, citing the spread of particularly contagious Omicron sub-variants.