Young women who received at least one dose of the Covid vaccine manufactured by AstraZeneca may be more likely to die from heart disease in the UK, according to an analysis of vaccination and mortality records in the UK published on Monday. 12 weeks after vaccination.
Those findings provide a big warning: Britain withdrew the use of AstraZeneca’s vaccine in young people under the age of 30 in April 2021, citing the rare but dangerous risk of blood clots forming . At that time, the young women who were vaccinated were mainly health care workers or medically vulnerable people, because those at high risk of Covid disease in terms of age, health or work. Their jobs are pre-vaccinated. Therefore, the results of the study may not apply to the general population.
“It is possible that clinically extremely vulnerable people are susceptible to the effects,” said Vahé Nafilyan, senior statistician at the UK Office for National Statistics and one of the study’s lead researchers. side effects of vaccination. The results were published Monday in the journal Nature Communications.
The AstraZeneca vaccine has never been approved for use in the United States.
The analysis found there were six heart-related deaths per 100,000 young women who had received at least one dose of the vaccine in the UK. In these women, the rate of cardiovascular-related death at 12 weeks after vaccination was 3.5 times higher than at 12 weeks. A blood clot that blocks blood flow can cause a heart attack or stroke.
The researchers did not find a significantly higher risk of death in any of the other subgroups or with the Pfizer-BioNTech mRNA vaccine, which is also widely used in the UK. And the study didn’t prove that the vaccine caused the death.
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Researchers and other experts emphasize that the benefits of the Covid vaccine still far outweigh the risks and that the rate of adverse events after vaccination remains very low.
In the analysis, there was an additional death for every 12,000 unvaccinated youth and an additional death for every 56,000 vaccinated youth.
“When you look at the side effects of vaccines, I think it’s very important to consider the benefits,” says Dr Nafilyan.
The researchers linked vaccination records to recorded deaths from any cause in people 12 to 29 years old. They looked at data starting on December 8, 2020, when the vaccine was launched in the UK.
Mortality data come from two independent sources: deaths registered before June 8, 2022 and hospital deaths on March 31, 2022.
The team found a very small increase in mortality 12 weeks after vaccination among young men who received the mRNA vaccine, but said the finding was not statistically significant. Only young women – just over 177,000 – who received a single dose of AstraZeneca had a higher risk of death.
Experts warn that the analysis does not definitively link vaccines to deaths.
“That was enough to pique my interest and say we should do more research on this,” said Daniel Salmon, director of the Institute for Vaccine Safety at the Johns Hopkins Bloomberg School of Public Health. But “I will not come close to drawing any causal conclusions.”
“Overall, it’s pretty reassuring, but it offers some vaccines and some populations that are worth further study,” Dr Salmon said.
Other studies have linked vaccine side effects to specific subtypes. Data from several countries link the Covid mRNA vaccine to a higher risk of myocarditis and pericarditis — inflammation of the heart or outer lining of the heart — especially in men between the ages of 12 and 29. .
Within weeks of its introduction, the AstraZeneca vaccine has been associated with a rare blood clotting disorder, particularly in young women in the UK and other countries in Europe. Although AstraZeneca’s vaccine has not been approved by US regulators, the Food and Drug Administration in December 2020 approved a similar vaccine made by Johnson & Johnson.
In April 2021, the FDA called for a pause in the use of Johnson & Johnson’s vaccine, following reports of a clotting disorder in six American women. The agency withdrew its pause recommendation 10 days later and revised the vaccine label to warn of the risks.
A year later, the FDA again restricted the use of the vaccine, saying it should only be made available to people who were unable or unwilling to choose one of the mRNA vaccines. By then, the agency had received reports of 60 clotting disorders and nine deaths, out of 18 million doses of the drug administered.
“Fortunately, as more and more of this type of data is collected and made public, we can continue to be assured that the rate of serious side effects – known as adverse events – for both types vaccines are significantly low,” Dr. Susan Cheng, a cardiologist and epidemiologist at the Smidt Heart Institute in Cedars Sinai, Los Angeles, says about mRNA and non-mRNA vaccines.
“That said, while the odds of these adverse events are still very low, they are very important and they need to be accounted for and analyzed so we can better understand them.” they.”
