The US agreed to pay vaccine partners Pfizer Inc. and BioNTech SE US$3.2 billion in a deal for 105 million of their messenger RNA shots against COVID-19. 

The deal is for doses for adults, children and infants, and may include some shots that target the omicron variant, according to a statement from the companies. Deliveries are planned to begin as soon as late summer and continue into the fourth quarter. Payment will occur after the supply is delivered. 

Pfizer shares rose 0.6 per cent after US markets closed, while BioNTech’s American depositary receipts gained 1.4 per cent. 

The purchase of additional COVID supplies is the administration’s second to be announced Wednesday after agreeing to pay about US$275 million for 150,000 doses of an Eli Lilly & Co. antibody therapy that remains effective for treating omicron and its subvariants. The White House has been battling Congress over funds to make such purchases.

The Department of Health and Human Services and the Defense Department also have the option to buy as many as 195 million additional doses of the Pfizer-BioNTech vaccine, bringing the total number of potential doses to 300 million, according to the statement.

The new US vaccine contract with Pfizer and BioNTech also includes for the first time adult vaccines that will be packaged in single-dose vials, according to HHS. The development will pave the way for easier delivery of shots in hard-to-reach places, and less waste. 

On Tuesday, US regulatory advisers said that COVID shots from Moderna Inc. and the Pfizer-BioNTech partnership should be updated to include components that target omicron, the variant that’s driving case counts around the world. The Food and Drug Administration doesn’t have to follow its advisers’ recommendations, but it usually does.