By Peter Loftus and Paul Vieira 

Moderna Inc. expects a shortfall in Covid-19 vaccine doses it will deliver to countries outside the U.S., including Canada and the U.K., citing issues with its European supply chain.

The Cambridge, Mass., company said Friday the dose shortfall affects expected deliveries for the second quarter in a number of countries but didn't specify others beyond Canada and the U.K. The manufacturing problems won't affect U.S. supplies.

"The trajectory of vaccine manufacturing ramp-up is not linear, and despite best efforts, there is a shortfall in previously estimated doses from the European supply chain," the company said in a statement. "Vaccine manufacturing is a highly complex process, and a number of elements, including human and material resources, have factored into this volatility."

The shortfall marks the latest setback for efforts to ramp up manufacturing of Covid-19 vaccines. Moderna and Pfizer Inc. were initially able to make only limited quantities while they built manufacturing capabilities. In March, AstraZeneca PLC warned European officials its output was falling short of plans. Also that month, Merck & Co. agreed to help Johnson & Johnson make more of its vaccine.

Canadian Procurement Minister Anita Anand said in a statement distributed by her office that the next expected shipment from Moderna scheduled for the end of April would be cut in half, to 650,000 doses.

Canada had been anticipating 12.3 million doses from Moderna during the three-month period ending June 30. Ms. Anand said she expects a reduction in the second-quarter supply by as much as 16%.

"We are disappointed," Ms. Anand said. "Our government will continue to press Moderna to fulfill its commitments." Canada said Moderna advised officials the cutback is due to a slower-than-anticipated ramp-up of production capacity, and that other countries would be affected.

The timing of the Moderna cutback couldn't be worse for Canada, which has witnessed a sharp rise in Covid-19 infections -- so much so that the country's seven-day average of new, confirmed Covid-19 cases per million has exceeded the U.S. level for six days in a row. Furthermore, regional authorities across the country have canceled vaccination appointments, citing a lack of supply.

Based on the most recent Canadian government data, Moderna's vaccine accounts for 22% of the 12 million doses distributed across the country. Pfizer, in partnership with BioNTech SE, is the largest Covid-19 supplier to Canada, accounting for roughly 60% of doses distributed.

Canada said Friday it struck another deal with Pfizer to acquire an additional 8 million doses, which it said would help offset cutbacks from Moderna. Moderna's and Pfizer's vaccines are given in two doses, three or four weeks apart.

"We are concerned about the delays and production challenges around Moderna," Canadian Prime Minister Justin Trudeau said Friday at a press conference.

The U.K. government said it always knew vaccine supplies would fluctuate, but its vaccination campaign is on track to meet the target of offering a jab to all adults by the end of July. "Our vaccination programme continues to make phenomenal progress -- with over 41 million vaccines administered so far," a government health spokeswoman said.

Moderna has two supply chains for producing its vaccine.The company manufactures the vaccine for the U.S. at its plant outside Boston, and its contract manufacturing partner Lonza Ltd. also makes it at a plant in Portsmouth, N.H. Other partners handle vial-filling and packaging at U.S. sites.

Moderna has been ramping up its Covid-19 vaccine production for the U.S. and expects to deliver a total of 300 million doses by the end of July. So far, it has delivered more than 117 million of those doses.

Outside the U.S., Moderna has delivered about 15 million doses from a separate supply chain, which includes production at Lonza's plant in Switzerland and partners' facilities elsewhere that handle vial-filling and packaging.

In addition to the U.K. and Canada, Moderna has signed supply contracts with the European Union, Japan, South Korea, the Philippines, Switzerland, Colombia, Israel, Taiwan, Qatar and Singapore.

The company has said it expects to make 700 million to one billion doses globally for 2021.

Moderna said Friday that in response to high global demand, it and its manufacturing partner Lonza are trying to deliver a sustained supply in the shortest time frame possible.

The company said it is making investments to support production increases globally, and explore other potential collaboration opportunities.

--Jason Douglas contributed to this article.

Write to Peter Loftus at peter.loftus@wsj.com and Paul Vieira at paul.vieira@wsj.com

 

(END) Dow Jones Newswires

April 16, 2021 15:22 ET (19:22 GMT)

Copyright (c) 2021 Dow Jones & Company, Inc.