The second shot of AstraZeneca's COVID-19 vaccine must not be given to anyone who has had blood clots with low blood platelets after receiving the first, Europe's medicines regulator said on Friday.
The recommendations for healthcare professionals were provided by the European Medicines Agency (EMA) as part of an ongoing review into rare, but severe blood clots possibly linked to inoculation after the shot and also Johnson & Johnson's coronavirus vaccine.
The EMA has been looking into such clots in the abdomen and brain since March and has since recommended that both vaccine labels carry a warning on the clotting issues while maintaining that their overall benefits outweighed any risks.
On Friday, the EMA also said that patients must be monitored for signs of blood clots or low platelets within three weeks of receiving the first shot of AstraZeneca's vaccine, Vaxzevria. It said that special care must be provided to those with clots.