Nearly 5 million people in the United States had received J&J's vaccine as of Thursday morning, according to the U.S. Centers for Disease Control and Prevention.
"They should have listened to the expert advice that was given to the government, and indeed to all governments, about not placing all our eggs in one basket".
The central bank ramped up buying of sovereign bonds after a surge in U.S. Treasury yields lifted borrowing costs in the bloc and threatened Europe's tentative recovery.
Cases of the virus have been increasing for several weeks in Spain, which has fully vaccinated some 3.02 million people and administered a total of 9.8 million shots.
Hancock emphasised the serious side effects were "extremely rare", adding that all three of the vaccines so far approved for use in Britain were "safe for all ages".
The Philippines has so far received 525,600 doses of AstraZeneca's vaccines, about a fifth of the country's total inventory, through the COVAX facility.
Mexico's drug regulator Cofepris said on Wednesday it has no current plans to limit the use of the Oxford/AstraZeneca COVID-19 vaccine to any age or group.
"I don't think that anything I have seen leads me to suppose that we will have to change the roadmap or deviate from the roadmap in any way," Johnson said.