The University of Oxford said it has paused a trial evaluating its COVID-19 vaccine co-developed with AstraZeneca in children and teenagers while it awaits additional information on the risk of blood clots from the UK’s Medicines and Healthcare products Regulatory Agency (MHRA).

The MHRA has previously concluded that the benefits of the vaccine outweigh any risks. But the European Medicines Agency (EMA), which has so far not found a causal link between the AZ vaccine and blood clots (DID, April 1), is expected to make an announcement Wednesday or Thursday on the latest findings from its ongoing safety review.

The World Health Organization has also found the vaccine’s benefits to outweigh the risks and an WHO spokesperson said yesterday that the organization’s position is unlikely to change.

In February, Oxford announced it planned to enroll 300 children and teens, aged six to 17 years, in a UK-based phase 2 trial assessing the vaccine’s immune response for this population. ― Jason Scott