800x Higher Incidence of Myocardial Injury After Booster
Scientists showed that after the first booster shot, around 2.8% of the people experienced mild heart injury. This is a significant increase compared to the very low numbers seen in hospitalized cases, which was only 0.0035%.
Vaccination-Associated Myocarditis and Myocardial Injury
"Understanding COVID-19 Vaccine-Associated Heart Problems: Myocarditis and Myocardial Injury"
COVID-19 vaccines can sometimes lead to heart issues like myocarditis and myocardial injury. These problems can be caused by inflammation or other factors. Doctors diagnose them based on symptoms and heart scans. mRNA vaccines are most effective but might have a higher risk of these heart issues in some people. The chances of getting myocarditis after the first 2 doses of certain vaccines are low but higher than some other vaccines."
Abstract:
This study examines heart issues, specifically myocarditis and myocardial injury, associated with SARS-CoV-2 vaccines. These issues are compared to COVID-19 infection, other viral myocarditis types, and vaccine-related heart disorders. The vaccine-related myocardial injury may result from an immune response causing inflammation, but other causes like microvascular thrombosis are also considered. Doctors diagnose these problems using symptoms and cardiac magnetic resonance imaging.
While endomyocardial biopsy can confirm myocarditis, it may not always show inflammation due to quick resolution or non-inflammatory causes. Myocarditis linked to SARS-CoV-2 vaccines is more commonly seen with mRNA platform vaccines, which are highly effective. The estimated crude incidences of myocarditis after the first 2 doses of BNT162b2 and mRNA-1273 vaccines are around 1.9 and 3.5 per 100,000 individuals, respectively, for people aged over 16 or over 12 years. These rates are higher than influenza vaccines but lower than smallpox vaccination-related myocarditis incidences in comparison to control populations.
In studies comparing mRNA vaccines and COVID-19 related heart problems, it was found that COVID-19 infection had a 3.5 times higher incidence rate compared to a 1.5 times increase for BNT162b2 and 6.2 times increase for mRNA-1273 vaccines. However, even though vaccine-related myocarditis occurs more in young adults and adolescents, it has lower risks of severe outcomes and faster recovery than COVID-19 infection. The reasons for this are that vaccine-related myocarditis usually doesn't involve other organs, and it follows a milder course compared to non-COVID viral myocarditis.
New Research Shows Low Risk of Myocarditis after Pfizer COVID-19 Booster
A recent study conducted in Israel reveals that the risk of developing myocarditis, an inflammation of the heart muscle, after receiving a booster dose of the Pfizer COVID-19 vaccine is low. The research, published in the American Heart Association journal Circulation, highlights that even when vaccine-related myocarditis does occur, the cases are generally mild. The study indicates that the risk is most significant among teenage boys and young men.
Dr. Dror Mevorach, the lead author of the study and a professor of medicine, as well as the head of the Immunology-Rheumatology Institution at Hadassah Ein Karem Medical Center in Jerusalem, emphasized the importance of understanding the link between this rare heart condition and COVID-19 vaccines. He also stated that monitoring the prevalence of myocarditis and providing extra attention to those most at risk is crucial. Dr. Mevorach is also the chairman of the Israeli Ministry of Health Committee for Identifying Myocarditis as an Adverse Effect of mRNA Vaccines.
Myocarditis refers to the inflammation of the middle layer of the heart muscle wall, known as the myocardium. This condition can be triggered by a viral infection and may lead to the weakening of the heart muscle and its electrical system, resulting in irregular heartbeats. While it can resolve naturally or with treatment, it also has the potential to cause lasting damage to the heart.
Recent research conducted by various public health agencies, including the U.S. Centers for Disease Control and Prevention, has indicated a potential increased risk of myocarditis following mRNA COVID-19 vaccines. Specifically, a study conducted by the Ministry of Health in Israel found a low occurrence of myocarditis after individuals received both the first and second doses of Pfizer's vaccine. However, researchers have expressed concerns about the possibility of a third dose, the booster shot, having an even higher risk of myocarditis, particularly among young men and teen boys.
.In the new study, researchers analyzed health data for people who developed myocarditis following a third dose of the Pfizer vaccine, which was given to nearly 4 million Israeli adults between July 31 and Nov. 5, 2021. Within the first 30 days of receiving the booster, there were 35 reported cases of myocarditis. An additional 56 cases were reported after 30 days. Of those, 28 cases were confirmed or considered probable, and 18 of those occurred within a week of the booster being given.
ll 28 cases were considered mild. Patients recovered after spending an average of three to four days in the hospital. Across all ages, the risk of developing vaccine-related myocarditis was nine times higher for men than women. Males ages 16-19 faced the highest risk, with young men ages 20-24 having the second-highest risk.
The risk of developing myocarditis among males ages 16-19 after a third dose was about 1 in 15,000. Other research shows COVID-19 infection poses a higher risk for myocarditis than vaccines.
The risk for developing myocarditis was lower following a booster than following a second dose of the vaccine, the researchers reported.
In a recent study, scientists examined health records of individuals who experienced myocarditis after receiving a third dose of the Pfizer vaccine. This booster shot was administered to nearly 4 million adults in Israel between July 31 and November 5, 2021. Within the initial 30-day period following the booster, there were 35 documented cases of myocarditis. After the first 30 days, an additional 56 cases were reported. Among these, 28 cases were confirmed or considered probable, and interestingly, 18 of them occurred within one week of receiving the booster.
Fortunately, all 28 cases were classified as mild, and patients typically recovered after spending an average of three to four days in the hospital. Notably, across all age groups, the risk of developing vaccine-related myocarditis was nine times higher in men compared to women. Within specific age brackets, males between 16 and 19 years old faced the highest risk, followed by young men between 20 and 24 years old.
he calculated risk of myocarditis in males aged 16-19 after receiving the third vaccine dose was approximately 1 in 15,000. Moreover, other research indicates that the risk of myocarditis due to COVID-19 infection is higher than the risk associated with vaccines.
he study's findings also revealed that the risk of developing myocarditis following a booster dose was lower compared to the risk following the second dose of the vaccine.
Mevorach proposed two potential explanations for this observation. Firstly, individuals who experienced myocarditis after receiving the second COVID-19 vaccine dose may have been medically advised not to proceed with a third dose as a precautionary measure. Secondly, the timing of the doses could play a role. While the first and second doses are usually spaced around three weeks apart, the interval between the second dose and the booster was longer, approximately 20 to 24 weeks.
As for the higher risk of myocarditis in young men and teenage boys following a COVID-19 vaccine, researchers remain uncertain about the exact reasons and believe that further investigation is necessary to gain a better understanding of this phenomenon.