Pharma giant Pfizer has tried to ease concerns in Europe about deliveries of its coronavirus vaccine as nations across the world doubled down on restrictions to fight the rampaging pandemic.

Worries have grown that delays in the delivery of Pfizer-BioNTech shots could hamper a European vaccine rollout which has already faced heavy criticism across the continent.

Work is ongoing at the Pfizer plant in Belgium to increase capacity, and the firm and its German partner BioNTech said it would allow them to “significantly” scale up vaccine production in the second quarter.

Deliveries would be back to the original schedule to the EU from January 25, they pledged, according to an AFP report.