The European Union's drug regulator says it found a "possible link" between the AstraZeneca vaccine and a rare blood-clotting disorder.
But it says the benefits of the shot still outweigh the risk.
In a statement, the European Medicines Agency placed no new restrictions on adults getting the vaccine.
The EMA, the World Health Organization and numerous other health authorities have said repeatedly that the AstraZeneca vaccine is safe and effective.
