"It seems that the four vaccines that are approved in the European Union are protective against all strains that are circulating in Europe, including the Delta variant," said Marco Cavaleri, European Medicines Agency's (EMA) head of vaccine strategy, during a news briefing on Thursday (July 1).

The highly transmissible Delta variant of SARS-CoV-2 was first identified in India and has led to a wave of new infections around the world.

To monitor potential new threats, vaccine makers have exposed the blood of vaccinated people to viruses engineered to have the typical features of the variant of concern to determine if neutralizing antibodies quell that virus.Currently, the European Union has four COVID-19 vaccines authorized: those from Pfizer and BioNTech, AstraZeneca and Oxford, Moderna and Johnson & Johnson.

The EMA said it would proceed with evaluating data from CureVac's coronavirus vaccine after the German biotech firm said late on Wednesday its jab was only 48% effective in a final analysis.