Oxford University announced on Tuesday that it was suspending a trial of the Covid-19 vaccine that it developed with AstraZeneca on children and teenagers while British regulators investigate a potential blood clot link in adults.
“Whilst there are no safety concerns in the paediatric clinical trial, we await additional information from the MHRA on its review of rare cases of thrombosis/thrombocytopaenia that have been reported in adults, before giving any further vaccinations in the trial," the university said in a statement.
"Parents and children should continue to attend all scheduled visits and can contact the trial sites if they have any questions.”
The Medicines and Healthcare Regulatory Agency (MHRA) revealed on Saturday that seven people in the country had died from rare blood clots after getting the shot out of a total of 30 identified cases, while more than 18 million doses were administered in the country.
The British regulator said it wasn't clear if the shots are causing the clots.
'Benefits continue to outweigh risk'
"The benefits of COVID-19 vaccine AstraZeneca in preventing COVID-19 infection and its complications continue to outweigh any risks and the public should continue to get their vaccine when invited to do so,'' said Dr June Raine, the agency's chief executive.
Marco Cavaleri, head of health threats and vaccine strategy at the European Medicines Agency told Rome's Il Messaggero newspaper on Tuesday there was a causal link between AstraZeneca's coronavirus vaccine and rare blood clots.
“It is becoming more and more difficult to affirm that there isn’t a cause-and-effect relationship between AstraZeneca vaccines and the very rare cases of blood clots associated with a low level of platelets,” Cavaleri was quoted as saying.
He added it was unclear what the connection was and that the benefits of taking the shot still outweighed the risks of getting COVID-19.
'Review still ongoing'
Asked about Cavaleri’s comments, the EMA press office said its evaluation “has not yet reached a conclusion and the review is currently ongoing.” It said it planned a press conference as soon as the review is finalized, possibly Wednesday or Thursday.
In Geneva, the World Health Organization said its experts were also evaluating a possible link between the AstraZeneca vaccine and rare blood clots — and that it might have a “fresh, conclusive assessment” before Thursday.
In March, more than a dozen countries, including Germany, suspended using AstraZeneca over the blood clot issue.
Most EU nations restarted on March 19 — some with age restrictions — after the EMA said the benefits of the vaccine outweighed the risks.
At the time, the EMA recommended the vaccine's leaflet be updated with information about the rare clots.
Any further doubts about the AstraZeneca vaccine would be a setback for the shot, which is critical to Europe’s immunization campaign.