EU Covid-19 vaccinations to start December 27
Her spokesman Eric Mamer told journalists the rollout was conditional on the European Medicines Agency authorising the use of the Pfizer/BioNTech vaccine when it meets on Monday.
Britain and the United States are already inoculating people with that vaccine under emergency national authorisations.
The EU is carrying out a coordinated vaccination programme across its 27 member states to ensure fair access to doses.
The European Commission has sealed contracts with seven suppliers of potential vaccines to ensure all adult EU citizens will eventually be able to be inoculated.
Member states will decide who gets priority for the injections, but the elderly and healthcare workers treating Covid-19 patients will be at the front of the queues.
The vaccine developed by US giant Pfizer and German firm BioNTech has proven to be 95 percent effective in global trials where two doses are injected three weeks apart.
In Europe, that vaccine is produced in a Pfizer facility in Belgium and sent out in trucks and planes. It must be stored at -70 degrees Celsius (-94 degrees Fahrenheit) to keep it viable, but can be transported for short periods at 2-8 degrees Celsius.