Merck to help make J&J's vaccine: WH official

Pharmaceutical giant Merck will help manufacture its rival Johnson & Johnson's newly approved coronavirus vaccine, according to a White House official, in an effort to ramp up supply of the single dose vaccine more quickly.

J&J's production has been slower than promised.

Under its contract, the company was supposed to deliver 12 million doses by the end of February, but had less than 4 million ready to ship when the vaccine was authorized on Saturday.

Though J&J says it will be able to provide the full 100 million doses it has agreed to supply by its original midyear deadline.

More doses sooner could speed the U.S. vaccination effort considerably, because as a one-dose vaccine it is possible to inoculate twice as many people with the same number of shots.

The other two U.S.-approved vaccines - from Pfizer and BioNTech and Moderna - require two doses.

The collaboration with J&J comes after Merck in January scrapped plans to develop its own COVID-19 vaccine candidates.