Tens of millions of migrants may be denied Covid-19 vaccines from a global programme because some major manufacturers are worried about legal risks from harmful side effects, according to officials and internal documents from Gavi, the charity operating the programme, reviewed by Reuters.

Nearly two years into a pandemic that has already killed more than 5 million people, only about 7% of people in low-income countries have received a dose. Vaccine deliveries worldwide have been delayed by production problems, hoarding by rich countries, export restrictions and red tape. Many programmes have also been hampered by hesitancy among the public.