Scientists who have watched with dismay a series of disputes over AstraZeneca's Covid-19 vaccine say strong efficacy data from a large US trial should lay concerns to rest, but worry the skirmishes may leave a lasting mark on public trust.

Spats with governments across Europe about production, supplies, possible side effects and the vaccine's merits have dogged the Anglo-Swedish drugmaker for months. And a highly unusual public rebuke from US scientists monitoring the government-funded trial this week added to its woes...