The European Union has tightened its rules on coronavirus vaccine exports, giving it a clearer right to block shipments to countries with higher inoculation rates such as Britain, or which are not sharing doses they produce.

The move comes as member states struggle to contain a third wave of the epidemic and kick-start vaccine programmes slowed by a shortfall in deliveries.

The new rules expand existing measures aimed at ensuring that planned exports by drugmakers do not threaten the bloc's supply, according to Reuters.

They widen the net by adding 17 previously exempt countries — including Israel, Norway and Switzerland — to the list of countries for which exports of EU-produced vaccines require licences.