[ad_1]
The European Medicines Agency (EMA) continues to consider the AstraZeneca vaccine against covid-19 as “safe and effective” against covid-19, although it has not been able to demonstrate that there is a cause-effect relationship between the rare cases in which it was the formation of blood clots with a decrease in platelets registered in several countries and that led several governments to suspend the immunization campaign with this vaccine. “The recommendation is that health professionals are aware of possible side effects,” said Emer Cooke, director of the EMA, ensuring that more studies will be conducted.
The EMA found no evidence that there was a problem with specific lots of the AstraZeneca vaccine. “That relationship just doesn’t exist,” Sabine Straus said., Secretary of the Risk Assessment and Pharmacovigilance Committee of the EMA, leaving aside the hypothesis initially raised.
The agency’s experts, along with other experts, reviewed 469 reports of these thromboembolic events in Europe. The most serious are seven related to the formation of clots in multiple blood vessels (disseminated intravascular coagulation) and 18 to venous thrombosis in the brain. “A cause-and-effect relationship with the vaccine has not been demonstrated, but it is possible and warrants further analysis,” said Sabine Straus.
These serious cases of blood clots and bleeding at the same time are not typical thrombotic phenomena, such as pulmonary embolism, so they have caused more concern and forced the intervention of the EMA to carry out a scientific investigation. There was an urgent need for a response, as around 10 and a half of European countries discontinued the use of the AstraZeneca vaccine, delaying the immunization of the population against COVID-19.
“It remains very important to study the relationship between these rare clotting episodes and vaccination,” Emer Cooke said, ensuring that studies, including epidemiological studies, will continue on the frequency with which these clots and thrombotic episodes occur.
Sabine Straus, secretary of the Pharmacovigilance and Risk Assessment Committee (PRAC), said healthcare professionals will be encouraged to look for warning signs in vaccinated people. “A warning booklet, describing these cases, will also be produced and distributed with the vaccine,” he added.
In the United States, there are reports of effects on blood clotting of the Moderna and Pfizer-BioNtech vaccines, which use a different technology, that of messenger RNA, which introduces into the body only the genetic material necessary to produce a protein of the new coronavirus. . AstraZeneca-University of Oxford uses as a vector to insert this SARS-CoV-2 protein into the body, an attenuated version of a chimpanzee adenovirus, a virus that normally causes colds.
Of particular interest to the EMA experts were cases of blood clots in the brain, leading to cerebral venous thrombosis, a difficult problem to treat.
In Germany, seven people between the ages of 20 and 50 had this problem up to 16 days after being vaccinated, according to the Paul Ehrlich Institute, the national vaccine surveillance authority. The normal rate of these incidents in the general population in Germany is one case per 1.6 million inhabitants, and five million doses of the AstraZeneca vaccine have been administered throughout the European Union. These cases in Germany were therefore much more than expected.
Despite this, they are rare events, emphasized the EMA and other health authorities, such as the World Health Organization and the Centers for Disease Control and Prevention – Africa (CDC Africa), which until now continue to recommend the use of the AstraZeneca vaccine. to protect against a life-threatening disease, covid-19. On the other hand, venous thromboembolisms are the third most common cardiovascular disease in the world. They happen whether people get vaccinated or not, ”Hans Kluge, director of WHO Europe, told a news conference. online this Thursday, cited by Financial times.
However, the WHO has announced that its global advisory committee on vaccine safety will issue an opinion on this issue later on Thursday.
The UK Medicines and Healthcare Products Regulatory Agency (MHRA) issued a statement on Thursday saying British citizens should continue to be vaccinated with AstraZeneca because the benefits outweigh the risks. However, a study will continue on five detected cases of “a very rare and specific type of blood clot in the veins of the brain (cerebral venous thrombosis) that occurred together with a reduction in the number of platelets (thrombocytopenia) “.
However, underlines the MHRA, the frequency of these cases “is less than one in a million people vaccinated in the UK, and they can also occur naturally; a causal relationship with vaccination has not been established.”
John Nkengasong, director of CDC Africa, said that “the benefits of the AstraZeneca vaccine continue to outweigh the risks” and that countries should continue to vaccinate. This vaccine is the most widely used in African countries and in the international initiative COVAX, which aims to bring vaccines to the poorest countries, but some African countries have also suspended immunization campaigns, given the news of adverse effects from Europe.
The WHO regional director for Africa said on Thursday that a third wave of covid-19 is expected in several countries on the continent in the coming weeks and encouraged states to continue their vaccination campaigns without pauses, reports the Lusa agency. “We are in a race against time. The more people who are protected, the less likely they are to have mutations that produce more dangerous variants of the virus, putting the entire world in danger, “said Matshidiso Moeti at an online press conference, also marked by doubts about the AstraZeneca vaccine.
