To meet its global vaccines pledge, the U.S. seeks to replace the millions of AstraZeneca doses under review.

With less than two weeks remaining to fulfill President Biden’s pledge to share 80 million doses of coronavirus vaccine with countries in need, production problems at an Emergent BioSolutions manufacturing plant are forcing the administration to revise its plan to send AstraZeneca doses overseas.

Officials are now working to replace tens of millions of doses of the AstraZeneca vaccine that it had initially planned to include in the donation with others made by Pfizer and BioNTech, Moderna and Johnson & Johnson, according to people familiar with the discussions. Those three vaccines are authorized for emergency use in the United States; AstraZeneca’s is not.