AstraZeneca Plc has told Thailand it should be able to supply around six million doses of its Covid-19 vaccine per month, leaked correspondence showed, contradicting assertions by Thai officials that the government had been promised 10 million.

Thailand's push for 10 million monthly doses comes as it considers imposing vaccine export curbs on Thai-manufactured vaccines to shore up domestic supplies, a move that could create problems for its neighbours, some of which are battling similar or more severe coronavirus crises.

But a June 25 letter by AstraZeneca to Thailand's health minister showed that the Anglo-Swedish drugmaker...