LONDON – Oxford University announced Tuesday that it had suspended a small UK study testing the Covid-19 vaccine developed with AstraZeneca in children and adolescents as it awaits further data on rare blood clotting problems in adults who got the shot.
The trial stoppage is the latest blow to the vaccine, which was once hailed as a milestone in the fight against the pandemic after several countries restricted its use amid reports of medical problems following vaccination.
There were no safety concerns in the pediatric study, Oxford University said, adding that it would await guidance from the UK drug watchdog before any further vaccinations.
The university announced in February that it would enroll 300 UK-based volunteers, ages 6-17, as part of this study.
The European Medicines Agency (EMA) is currently reviewing reports of an extremely rare cerebral blood clot known as cerebral venous sinus thrombosis (CVST) following the AstraZeneca shots and is expected to announce its results on Wednesday or Thursday.
A senior EMA official has said there is a clear link between the vaccine and CVST, although the direct cause of the clot is still unknown.
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The World Health Organization, which is working with other regulators to closely examine the latest data on AstraZeneca’s vaccine, said Tuesday there was no reason to change its assessment that the benefits of the shot outweigh the risks.
The two-dose Oxford-AstraZeneca vaccine is cheaper and easier to distribute than some of its competitors.
Spats with governments across Europe about production, supply, possible side effects and the benefits of the vaccine have been following the Anglo-Swedish drug manufacturer for weeks.
Anthony Fauci, the leading U.S. infectious disease doctor, told Reuters last week that the U.S. may not need AstraZeneca’s vaccine even if it gets regulatory approval.