The EMA recognizes the association of the AstraZeneca vaccine with very rare cases of thrombi but continues to recommend its use

The European Medicines Agency believes that the benefits continue to outweigh the risks

The EMA thus concludes its evaluation of the safety of the AZ vaccine, which began after the detection of the first deaths from thrombosis in early March

This Tuesday, the head of Vaccine Strategy of the EMA, Marco Cavaleri, pointed out that there was “a link” between the vaccine and the rare cases of thrombi investigated

The EMA recognizes a possible link of AstraZeneca vaccine with very rare cases of blood clots, but consider that the overall benefits of the vaccine to prevent COVID-19 outweigh the risks of side effects.

This was explained by the European Medicines Agency in a press conference this Wednesday in which the director, Emer Cooke, presented the evaluation of the EMA on the Vaxzevria vaccine (formerly AstraZeneca) related to cases of thromboembolic events.

Causal “link” to the vaccine

The Agency’s report comes after, this Tuesday, the head of Vaccine Strategy of the EMA, Marco Cavaleri, pointed out that there was “a link” between these cases of thrombosis and the vaccine. In an interview with the Italian newspaper Il Messagero, Cavaleri confessed that “it is increasingly difficult to say that there is no cause-and-effect relationship between vaccination with AstraZeneca and those very rare cases of unusual blood clots associated with low platelet counts. . In my opinion, We can say, at this point, that it is clear that there is a link with the vaccine. ” Was the first time a certain connection was established between the vaccine and those thrombus episodes. The EMA was quick to deny his statements, recalling that “no conclusion has yet been reached as the review of the vaccine is still ongoing.”

On the same Tuesday, asked about it, the president of the government Pedro Sánchez avoided the question of whether these statements by Cavaleri could have an impact on vaccination with AstraZeneca. “All vaccines have the validation of the EMA”, Sanchez settled, while again launching a “message of security to the population” and of “confidence that all vaccination processes “underway in Europe” have the maximum guarantees “. Despite which, this Wednesday, one of the Autonomous Communities, that of Castilla y León, has decided to act on its own and temporarily suspend vaccination with AstraZeneca.

The truth is Cavaleri is not the only one who has pointed out some causality between the vaccine and those rare clotting events. In UK, Professor Saad Shakir, director of the Drug Safety Research Unit (DSRU) of the Southampton University, said this Tuesday in The Guardian that the evidence accumulated in Europe and the United Kingdom on the links between the vaccine and those rare cases of thrombosis “is consistent with causality.”

One month pending the thrombi

Today’s report finally concludes the European Medicines Agency (EMA) review about the rare cases of thrombosis and coagulation detected in several countries and their possible relationship (or not) with this vaccine. The Pharmacovigilance Risk Assessment Committee (PRAC), the EMA body in charge of evaluating the safety of the drugs they authorize, has been meeting since Monday with the aim of ending your evaluation.

In their previous meeting, on March 31, the PRAC said that It did not rule out a cause-effect relationship between these cases and the vaccine, but it did not find clear evidence of that link either. between AstraZeneca and the development of blood clots with low platelets. Therefore, the conclusion, until now, remained the same: the benefits of this covid-19 vaccine outweigh the risks of any possible side effects. The vaccine is “effective” and “safe.”

Nevertheless, countries such as Germany and the Netherlands decided to stop vaccination with AstraZeneca in children under 60 years of age awaiting the final report from the EMA. Others like Spain or France, resumed vaccination after the first report from the agency in this regard, on the 18th, which announced that the vaccine was “safe.” Spain even decided to expand it: since then, vaccination with AZ has been extended to 65 years (before it was for those under 55).

Risk factor’s

For now no specific risk factor has been identified that can explain these rare cases thrombosis and coagulation, with low platelets, occurring after vaccination. “The revision has not identified any specific risk factors, such as age, gender, or a prior medical history of bleeding disorders “said the EMA in its March 31 report.

But clinical evidence indicates that most cases have been registered in women, all under the age of 60, Therefore, possible specific risk factors associated with being a woman are also investigated.

There is a hypothesis that takes force, a week ago. That of the German hematologists who claim to have discovered the cause of these strange episodes of thrombi, and even suggest a treatment. The trigger would be an immune reaction very similar to a rare heparin side effect called HIT, which causes antibodies to attack platelets. Something that it also points to Shakir, from the University of Southampton. “There is a clear clinical description and similarities between all the cases. Thrombosis, low platelets and various hematological changes. All of them are consistent with an event that occurs very, very rarely, and only with one drug, heparin. “

What would not be clear, and neither do the German hematologists clarify in their study, is if this rare immune reaction may be related to the vaccine. This study is pending review, but has been taken very seriously by the scientific community. So much so that in several countries are already incorporating it into covid-related medical practice.