Netherlands backed vaccine research paused over possible side effect

AstraZeneca and the University of Oxford temporarily halted their clinical trials on a coronavirus vaccine due to a potential serious side effect in one of their British test subjects, AstraZeneca said in a statement to several international media. This is one of the vaccines that the Netherlands is backing.

The pharmaceutical giant did not say exactly what the side effect was and when it occurred. The pause in the trial is to determine whether the illness was caused by the vaccine, or whether the British subject got ill for another reason. According to AstraZeneca, the pause is a routine part of the vaccine trial procedure.

It is unclear how long this pause will last, but the company hopes that the trial can still be completed on time.

Clinical trials for the AstraZeneca vaccine were ongoing in the United States and the United Kingdom, with smaller studies in Brazil and South Africa.

University of Washington researcher Deborah Fuller, who is working on a different Covid-19 vaccine that hasn't started human testing yet, told AP news that this potential side effect was likely serious enough to require hospitalization for it to trigger a pause. "This is not something to be alarmed about," Fuller said. She rather finds it reassuring that the company is pausing to trial to figure out what is going on and carefully monitoring the health of participants.

The first test results with this vaccine, called AZD1222, were published in July and were positive. Some side effects were noted, but none of them serious.

In June the Netherlands teamed up with France, Germany and Italy, pooling their purchasing power to acquire between 300 and 400 million units of this vaccine by AstraZeneca. The Netherlands also negotiated with the EU for the purchase of four other vaccines, including one being developed by Janssen in Leiden. Experts said that the Oxford vaccine showed the most promise.