A warning from AstraZeneca that initial supplies of its Covid vaccinations to Europe will be lower than expected has sparked new concern over the rollout of inoculations, with some countries planning for a sharp drop in deliveries.

The announcement by the British pharmaceutical firm followed another last week by Pfizer, which said it would delay shipments of its vaccine for up to a month due to works at its key plant in Belgium.

The companies' warnings come with worry deepening over new Covid-19 variants, particularly one that emerged in Britain and which is more infectious than the original strain.

Overall, Europe has now recorded more than 692,000 deaths and nearly 32 million infections. The European Union has so far approved vaccines from Pfizer and its German partner BioNTech as well as from US company Moderna.