The European Union's drugs regulator has pointed to a possible link between the coronavirus vaccine developed by AstraZeneca and rare cases of blood clots.
Blood clots have been found among people who were given a dose of the coronavirus vaccine jointly developed by AstraZeneca and Oxford University.
European Medicines Agency officials met with reporters to disclose its findings on the matter on Wednesday.
The EMA said unusual blood clots with low blood platelet counts should be listed as very rare side effects of the AstraZeneca coronavirus vaccine.
It noted that most of the cases reported so far have occurred in women under the age of 60 within two weeks of the person receiving their first dose.
The blood clots reportedly occurred in veins in the brain as well as in arteries. It maintains specific risk factors have not been confirmed.
Meanwhile, Britain's Joint Committee on Vaccination and Immunisation told reporters on Wednesday that adults aged under 30 with no underlying conditions should be offered an alternative to the AstraZeneca vaccine, citing the "slightly higher incidence" of their suffering an adverse event.
JCVI says that the risk of blood clots is very rare, occurring in four out of every million who were given jabs.
Both the EMA and JCVI expressed the view that the possibility of blood clots occurring is rare, and that the benefits of the vaccine continue to outweigh the risks for people who receive it.