That struck some in Brussels as rich, given that last September, Mr. Johnson threatened to override Britain’s landmark treaty with the European Union, in violation of international law, if the two sides failed to strike a trade deal.
At home, the prime minister lost no time in wielding the vaccine issue as a club against his political rivals. On Wednesday, in the House of Commons, Mr. Johnson mocked the Labour Party leader, Keir Starmer, for saying he wished Britain had remained in the European Medicines Agency, which has been slower to approve vaccines than Britain’s health regulator.
Mr. Starmer dismissed the claim as “nonsense” before admitting later that he had once said Britain would be better off staying under European regulators (though he noted that this was not the position of his party).
Britain, legal experts pointed out, would have had the authority to approve vaccines just as fast even if it were still in the European Union, though it would have had less political leeway to act alone.
Still, it was a damaging retreat for Mr. Starmer, one that set off alarm bells in the Labour Party’s ranks. Mr. Johnson’s Conservative Party has kept a modest lead over Labour in polls, despite his government’s handling of the pandemic, which has been marked by delays, reversals and mixed messages.
Britain recently passed 100,000 deaths, the highest toll of any European country. For now, though, voters appear more focused on the vaccine rollout, which reached a milestone this week of 10 million people getting first doses.
While much of the credit for the rapid distribution should go to Britain’s National Health Service, according to experts, it is also a tribute to the government’s early investment in promising vaccines, like one produced by Oxford and AstraZeneca.