European Union countries are waiting for a judgment from their drug regulator in regard to the safety of AstraZeneca's coronavirus vaccine after reports of blood clots in some people who received it.
The European Medicines Agency says its safety committee will hold an extraordinary meeting on Thursday to decide on how to respond.
Some EU countries have suspended the use of the British-made vaccine over reported blood clots and other side effects.
The governments of Germany, France, Italy and Spain announced on Monday that they will suspend the drug as a precautionary measure.
The countries say they will decide whether to resume using the vaccine following the EMA's decision.
In the past the EMA has said that the benefits of the vaccine overweigh the risks of not receiving it.
AstraZeneca said in a statement on Sunday that it would like to offer its reassurance on the safety of the vaccine based on clear scientific evidence.
Britain has said it will continue to use it.