The EU insists its controls are a temporary scheme, not an export ban. But the World Health Organization is among those criticising the move, saying it could have a knock-on effect around the world.
This decision comes with the EU in a very public dispute with drug-maker AstraZeneca over supplies, and under growing pressure over the slow pace of vaccine distribution.
Under the new rule, vaccine firms will have to seek permission before supplying doses beyond the EU. Its 27 member states will be able to vet those export applications.
Vaccines produced by Pfizer in Belgium are currently being exported to the UK, and the EU insists that some of the AstraZeneca vaccine produced in England is destined under contract for EU citizens.
The EU is also in a supply dispute with Pfizer, which is set to fall short of the contracted vaccine volume for the EU by the end of March. Pfizer says the reason for that is the urgent expansion of its facility in Puurs, Belgium.
AstraZeneca's shortfall to the EU is expected to be about 60% in the first quarter of 2021./Bbc