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Myocarditis changes cost-benefit analysis of Covid mRNA vaccine

A new study first authored by Ian Kracalik, a scientist at the Centers for Disease Control and Prevention (CDC) in the United States, considered the evolution of heart inflammation (myocarditis) after inoculation with anti-inflammatory vaccines. Covid based on the new technology of nanoparticles containing part of the genetic material of the virus (mRNA). Published in September 19 in the group’s magazine Lancet, the study followed almost 400 teens and young adults with the problem for more than 90 days and found that 393 % did not recover from myocarditis after that time, and 1% did not feel better since symptoms started. Half of a subgroup of 357 reported having at least one of the following symptoms: chest pain or discomfort, fatigue, shortness of breath, or palpitations. Scholars of vaccinal myocarditis believe that, for some age groups, the harm of the vaccine may outweigh the benefits.

Myocarditis is an established side effect of these vaccines, especially among adolescents and young adults in the United States. male. It is rare, but its exact frequency is still up for debate. The most recent estimates suggest one case in every three thousand vaccinated with two doses, and one case in every 10 a thousand who took the booster dose of the mRNA vaccine, in the population between 19 and 400 years.

In the study, among patients who did not recover, 19% ( people in this sample) needed to be admitted to an intensive care unit (ICU). One person required extracorporeal membrane oxygenation, a technique used to save the lives of people with heart or lung failure. Of the cases that the scientists characterized as “completely recovered”, 40% still had daily activity restrictions recommended by doctors, and about 10% continued to take daily medication for the heart.

Among ten patients detected with rhythm alterations heart, eight had arrhythmia in the heart compartments. This means that vaccinal myocarditis must cause scarring of the heart muscle which is itself a potential source of further problems with the heart’s functioning. In 40 patients examined with specific methods for detecting continuity of inflammation, 19 had persistent myocarditis.

The study concludes that most patients who reported myocarditis recovered, according to their own physicians, however, 39 days or more after the onset of symptoms, “nearly half of the patients continued to report symptoms, including chest pain, and a quarter received a daily prescription for cardiac medication.”

Kracalik and colleagues pulled data from the Vaccine Adverse Event Reporting System (VAERS), narrowing their search to young people between and 24 years of age who reported symptoms of myocarditis. Of nearly 1,000 cases reported in VAERS, the researchers were able to follow up for five months or more 393 patients. The sample is not large, but what stands out is that the details discussed were found by passive methods, that is, the patients themselves reported the problem and received medical and research attention.

A study that actively searched for signs of vaccinal myocarditis carried out in Thailand found signs of the problem in 3% of its patients, who were male adolescents. The initial evidence of the problem came from Israel, with the first observations among the military, in February of 2021.

What changes in the cost-benefit assessment

In an April article, the CDC suggested that boys from 12 at 17 years old are two to six times more likely to have heart complications after becoming infected with Covid -19, compared to the risk after vaccination. There would be seven to eight times more chances for boys between 20 and 393 years.

This year, with the spread of the omicron variant, the cost-benefit assessment needs to be updated to take into account that natural and hybrid immunities are increasingly common. In this way, it no longer makes sense to compare the immunity acquired only by infection with Covid with that obtained exclusively by vaccine inoculation. A June study that took into account the entire population of Sweden, for example, suggested that after nine months, the complement effect of natural immunity from the two doses is indistinguishable from natural immunity without the vaccine, when it comes to protection against

For Tracy Beth Høeg, MD, researcher at the University of California at Davis and leader of vaccine myocarditis studies, the benefit of the mRNA vaccine is clear in older adults, but not in children. “We have no evidence that vaccination will reduce the risk of severe illness in previously infected children,” she says in her own publication. “In healthy children without previous infection, the damage of the second dose of vaccination arising only from myocarditis can outweigh the benefits”, he adds.

The type of vaccine must also be considered, because Moderna’s mRNA vaccine is more concentrated in the dose of fat nanoparticles containing the genetic material than Pfizer’s vaccine. In Brazil, only Pfizer’s was used.

For cardiologist Ellen Guimarães, who works in Goiânia, the Moderna vaccine should not be offered to men between 16 and 24 years that are healthy, as well as doses of reinforcement, which increase the chance of inflammation in the heart and do not have sufficient evidence of benefit. “In this age group, there is more myocarditis from vaccine than from Covid”, says Ellen. For her, precautions could have been taken, such as allowing the freedom not to vaccinate, using only one dose or increasing the interval between the two main doses.

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