The World Health Organization has said there was no reason to stop using AstraZeneca's Covid-19 vaccine after several countries suspended the rollout over blood clot fears and as the EU added severe allergies to the list of possible side effects.

The WHO, which said its vaccines advisory committee was examining the safety data coming in, stressed that no causal link had been established between the AstraZeneca vaccine and clotting.

“AstraZeneca is an excellent vaccine, as are the other vaccines that are being used,” WHO spokeswoman Margaret Harris told reporters in Geneva, according to AFP.

“Yes, we should continue using the AstraZeneca vaccine,” she added, stressing that any concerns over safety must be investigated.