The European Medicines Agency (EMA) said on Thursday it was not willing to impose a 50% efficacy threshold for COVID-19 vaccines, adding full trial data was necessary for it to make a sound assessment on the benefits and risks of a shot.

German biotech CureVac NV said on Wednesday its COVID-19 vaccine was only 47% effective in a late-stage trial, missing the study's main goal and throwing into doubt the potential delivery of hundreds of millions of doses to the European Union. 

"We will need to collect all the final data from this clinical trial, and have a good analysis of the outcome throughout different regions, age groups and according to different variants," Marco Cavaleri, head of Biological Health Threats and Vaccines Strategy at the EMA, told reporters.

"So I think it is premature to enter into what this means (...) We always felt it was difficult to define upfront a threshold," he said.

(Reporting by Josephine Mason, Matthias Blamont; Editing by David Evans) ((matthias.blamont@thomsonreuters.com; +33 1 4949 5054 ; Reuters Messaging: @matthiasblamont))