Spain probing three blood clot cases in recipients of AstraZeneca vaccine

The Spanish Health Ministry on Wednesday said it is investigating three cases of thrombosis among recipients of the AstraZeneca Covid-19 vaccine, one of whom has died. One of the cases was reported on Monday, and the other two on Tuesday.

Spain is one of around 15 European countries to have temporarily suspended the use of AstraZeneca vaccines, as EU regulators continue to investigate.

After administering nearly a million shots of this vaccine, the Spanish Medicines and Health Products Agency (AEMPS) is underscoring that thrombosis, or the formation of clots inside blood vessels, “can also occur among the general population.”

All three cases share the peculiarity that the thrombosis events were associated with lower blood platelet counts

Spanish Health Ministry

But the ministry’s statement adds that “all three cases share the peculiarity that the thrombosis events were associated with lower blood platelet counts. This fact could suggest an abnormal activation of the coagulation system that might be associated with the formation of blood clots in locations that are unusual.”

The AEMPS said that, together with other regulatory agencies and the European Medicines Agency (EMA), it is carrying out a “comprehensive” investigation to determine whether there is a causal effect, besides the coincidence in time. Experts note that in mass campaigns such as this one, it is to be expected that some health events will happen that are in fact unrelated to the vaccine.

“The evaluation of these types of signs might find an alternative cause other than vaccine administration, or if it can be attributed to the vaccine, it can come up with measures to try to minimize the risk, such as identifying the factors that predispose people to develop this type of thrombosis and limiting the vaccine’s use when this factor is present.”

Deceased teacher

One of the cases under investigation is the death of a 43-year-old woman from Marbella in southern Spain who did not have any known pre-existing conditions. She went to the emergency services when she began feeling ill a few hours after receiving a shot of the vaccine, and complained about headaches, but doctors attributed it to normal side effects of the vaccine.

According to the regional daily Diario Sur, the woman returned to the hospital days later because she was still feeling unwell, and underwent scans that uncovered brain hemorrhaging, leading to an emergency surgery that failed to save her life. A math teacher at a local high school, she leaves two children behind.

Andalusian educators began getting vaccination appointments on February 22, beginning with early education and primary school teachers.

EU investigation

“The evaluation is looking at the available data related to all thromboembolic events reported after vaccination,” said the EMA in a statement. “National agencies are providing additional support to gather missing and incomplete information as quickly as possible, particularly where it relates to these unusual cases [of blood clots with unusual features such as low numbers of platelets].”

The EMA, which is hoping to have conclusions ready by Thursday, insisted that it “currently remains of the view that the benefits of the AstraZeneca vaccine in preventing Covid-19, with its associated risk of hospitalisation and death, outweigh the risks of side effects.”

The World Health Organization (WHO) is also recommending that countries continue administering the AstraZeneca vaccine.

English version by Susana Urra.