The European Union's (EU) drug regulator said on Thursday it had started a rolling review of the protein-based COVID-19 vaccine from French biotech firm Valneva, weeks after the EU signed a deal with the company for supplies of the shot.

The decision to start the real-time review was based on preliminary studies that suggest the vaccine, VLA2001, triggers an antibody response against the coronavirus, the European Medicines Agency (EMA) said in a statement. 

COVID-19 vaccines from Sinovac SVA.O , Sanofi-GSK and Russia's Gamaleya Institute are also under the EMA's rolling review, which aims to speed up possible approvals by studying data as it becomes available.

The European Commission last month signed its eighth deal for a COVID-19 vaccine  with Valneva, under which the company would supply up to 60 million doses of the shot over two years.

Valneva said in October its vaccine demonstrated efficacy "at least as good, if not better" than AstraZeneca's shot in a late-stage trial comparing the two, with significantly fewer adverse side effects.

AstraZeneca's vaccine is already approved in the EU, as are shots from Pfizer-BioNTech Moderna and Johnson & Johnson.

(Reporting by Pushkala Aripaka in Bengaluru; Editing by Aditya Soni) ((Pushkala.A@thomsonreuters.com; Twitter: @pullthekart; Mobile: +91 852 751 3793 ;))