European countries, including the UK, are set to receive fewer vaccines than expected from Pfizer starting next week, according to the Norwegian Institute of Public Health, further complicating the slow rollout of inoculations across the continent.

Geir Bukholm, director of infection control at NIPH, said the US pharmaceutical company told Norway on Friday morning that it would receive 18 per cent fewer doses than expected next week.

He added that the temporary reduction would affect all European countries as Pfizer reorganises its production in order to increase its capacity this year from 1.3bn doses to 2bn.

As it said it was working to deliver more doses than originally planned this year, Pfizer warned estimated volumes of coronavirus vaccine doses delivered to each country in a given quarter “may need to be adjusted”.

It confirmed that an increase in manufacturing meant modifications to the process were necessary and that these required additional regulatory approvals.

“Although this will temporarily impact shipments in late January to early February, it will provide a significant increase in doses available for patients in late February and March,” it said.

As a result, it said there may be fluctuations in orders and shipping schedules at its Belgian facility of Puurs in the immediate future.

Supply to the UK, which comes from the same plant, would also see fluctuations, Pfizer said.

Norway, which will now receive 36,075 doses next week instead of the 43,875 it had been expecting, said it did not know how long it would take Pfizer to get back to maximum capacity.

The Scandinavian country, like several other European countries, has been keeping a stockpile of doses in case there were problems with deliveries and said it would now draw from this emergency pool of vaccines. Mr Bukholm said Norway had enough to cover “a few weeks ahead” if needed.