The EU drug regulator on Wednesday said that both shots of a two-dose Covid-19 vaccine are vital for protection against the highly contagious Delta variant. The European Medicines Agency (EMA) and the European Centre for Disease Prevention and Control (ECDC) released a joint statement, urging citizens to get vaccinated and adhere to the recommended number of vaccine doses.

“This is particularly important taking into account the spread of the Delta variant of Sars-CoV-2...the need to protect citizens, especially those at risk of severe Covid-19, and the desire to open up our societies and relax restrictions,” the statement read.

The rapid spread of the Delta variant has forced many EU member states to either impose new restrictions or step back from earlier plans of fully reopening economies. The European CDC has estimated that by the end of August the Delta variant (B.1.617.2) will constitute 90 per cent of all coronavirus strains circulating in the EU.

Highlighting the higher transmissibility of the Delta variant and the possibility of higher risk of hospitalisation associated with it, the EMA stressed the need to speed up vaccination programmes and to close the “immunity gaps and opportunities for further emergence of variants, as soon as possible.”

“Preliminary evidence suggests that both doses of a 2-dose Covid-19 vaccine...are needed to provide adequate protection against the Delta variant,” the EMA said, adding "adherence to the recommended vaccination course is vital to benefit from the highest level of protection."

Amid debate over the “mix and match” of vaccines, the EMA said there are good scientific grounds to expect the heterologous vaccination strategy to be safe and effective when applied to vaccination against Covid-19. The agency stated that a heterologous vaccination strategy, in which a different vaccine is given for the second dose in a recommended 2-dose schedule, may allow populations to be protected more quickly and make better use of available vaccine supplies.