(Reuters) – The European Union’s drug regulator said on Thursday it hoped to have vaccines adapted to address coronavirus variants, such as Omicron, approved by September.

“Our priority is to ensure that adaptive vaccines are possibly approved by September at the latest to be ready for the rollout of new immunisation campaigns in the EU in the autumn,” said Marco Cavaleri, head of biological health threats and vaccines strategy at the European Medicines Agency (EMA).

“This would allow manufacturers to adjust their production lines accordingly.”

The mRNA vaccines, made by Pfizer-BioNTech and Moderna, are the furthest along, and clinical trials are ongoing.

Vaccine developers are investigating whether shots that target just one variant offer advantages over vaccines that target two variants, Cavaleri added, noting trial data was expected to come in over the next coupe of months.

Moderna is developing a potential next generation booster targeted at both the Omicron variant as well as the original strain of the coronavirus in the hope of producing broader protection. It expects first trial data in June.

Meanwhile, at the end of March, BioNTech and Pfizer broadened their original trial programme that prioritised a booster shot that targets only Omicron to also test a shot targeting Omicron and the original version of the coronavirus.

According to Cavaleri, about half of all EU citizens are fully vaccinated and boosted, while 15% of those over 18 have not received even one vaccine shot.

(Reporting by Natalie Grover and Ludwig Burger; Editing by Toby Chopra and Mark Potter)