Getting vaccinated against Covid significantly reduces the risk of suffering heart failure or thrombosis if you contract the infection, according to research led by the University of Oxford that has analyzed data from more than twenty million people in the United Kingdom, Catalonia and Estonia.
The results “are reassuring” for people concerned about the possibility that vaccination could have side effects on the cardiovascular system, says Daniel Prieto-Alhambra, professor of pharmacoepidemiology at Oxford and one of the main authors of the work.
Since the beginning of the pandemic, it has been observed that covid can trigger serious cardiovascular damage. Although vaccines were expected to help prevent them, sw reported cases of people suffering thromboembolisms after being vaccinated. These episodes, related to adenovirus-based vaccines such as those from Janssen and AstraZeneca, caused concern in people with cardiovascular risk factors, who wondered whether vaccination could increase the risk rather than reduce it.
The new research, published yesterday in the medical journal Heart, joins others carried out in the last three years that show that the benefits of covid vaccines outweigh the risks.
It has analyzed data from more than ten million people who were vaccinated and compared it to another ten million people who were not vaccinated. Among the people who contracted covid in both groups, it has been studied how many had heart failure or thromboembolisms.
In the acute phase of covid, defined as the first month after contracting the infection, the risk of heart failure and arterial thromboembolism is reduced by approximately half in people who have been vaccinated (that is, out of every 100 cases, about 50 are avoided). And the risk of venous thromboembolism is reduced by a fifth (of every 100 cases, 78 are avoided).
In the following months, having been vaccinated continues to have a protective effect against cardiovascular complications. Between six and twelve months after infection, the risk of heart failure remains approximately half, while that of arterial thromboembolism is reduced by 38% (38 out of every hundred cases are avoided) and that of venous thromboembolism by 38%. 50%.
Since this data is based on people who were infected in 2021, it is not clear that the percentages are exactly the same in people who are now vaccinated with booster doses, warns Daniel Prieto-Alhambra. But, although the numbers vary, it is proven that “vaccines reduce the risk of thrombotic and cardiovascular complications,” declares the researcher.
“Excellent work and analysis of national data from the United Kingdom, Spain and Estonia,” praised Eric Topol, director of the Scripps Institute in California, who was not involved in the research, in a tweet.
“It is a magnificent result to see that covid vaccines, in addition to reducing the risk of serious illness, reduce the risk of some post-covid complications,” says Clara Prats, co-author of the research, from the Biocomsc computational biology group.
According to Prieto-Alhambra, “all drugs and vaccines can have side effects. To decide correctly, it is necessary to study and adequately communicate the adverse effects, but it is also necessary to understand the effect of not treating or not vaccinating. In the case of covid, the infection causes a much greater risk of thrombosis than the vaccines.”
“There had been a lot of discussion about whether vaccines would create thrombosis,” recalls Roger Paredes, head of the infectious diseases service at the Cab Ruti hospital in Badalona. “This study shows that vaccines are the best way to protect against thrombosis as well.”
