EMA’s Blood Clot Investigation Finds AstraZeneca’s COVID-19 Vaccine Still Safe and Effective

The European Medicines Agency (EMA) has concluded its evaluation of a small number of blood-clot cases in patients vaccinated with AstraZeneca’s (AZ) COVID-19 vaccine, finding the two-shot inoculation is still safe and effective, though it could be associated with low levels of blood platelets in very rare instances.

The cases of blood clots moved more than a dozen EU member states to halt AZ vaccinations when patient deaths were reported, hindering Europe’s vaccination efforts as the continent sees a surge in infections (DID, March 16).

Emer Cooke, executive director of the EMA, addressed that situation directly, refraining from making a recommendation but saying that the “scientific conclusions adopted today provide member states with the information they need” to decide whether to begin inoculations with the vaccine again.

At least France and Germany have stated that they intend to resume use of the AZ vaccine if it’s found to be safe, and with the committee’s findings, they’re now expected to do so along with other member states, though some could conceivably conduct their own investigations. Italy has already announced its intention to begin using the vaccine again now that the EMA has reached its positive conclusion.

As frustrations have mounted over AZ’s continual delays in EU vaccine deliveries, the European Commission reportedly is sending a letter to the drugmaker in the hopes of resolving the supply issues through informal talks rather than resorting to the initiation of legal action. The company has cited export restrictions and production issues as reasons for the delays. Currently, it projects delivering 100 million doses to Europe in the first half of 2021, though it was supposed to provide 300 million doses by the end of June per its contract.

The EMA’s Pharmacovigilance Risk Assessment Committee (PRAC)’s investigation into the blood clots, which wrapped up Thursday, determined that the vaccine is not associated with an increased risk of blood clots nor is there evidence of a problem related to any specific vaccine batches or manufacturing facilities. After working with European thrombosis and blood disorder experts, the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) and other health authorities, the committee found that, in all, the vaccine’s benefits continue to outweigh its risks of side effects.

“The committee has come to a clear scientific conclusion: this is a safe and effective vaccine. It’s benefits in protecting people from COVID-19 with the associated risks and death of hospitalization outweigh the possible risks,” Cooke said. “A situation like the one we have just seen here is not unexpected. When you vaccinate millions of people, it’s inevitable that rare or serious instances or illnesses will occur in the time immediately following vaccination.”

Cooke did note, however, that in the scope of the agency’s review, a small number of cases of rare but serious clotting disorders associated with low levels of blood platelets were seen. Those unusual cases, which were almost all in women under age 55, could not be ruled out as being unrelated to the vaccine, and the committee has recommended including such risks in product information. It is currently investigating the rare incidents further, including conducting targeted observational studies to better understand their association with the vaccine.

The MHRA reached the same conclusion as the EMA after a scientific review, recommending that the AZ vaccine continue to be used in inoculation programs. — James Miessler