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Purpose: The number of patients presenting with vaccination-related cardiovascular symptoms after receiving mRNA vaccines (mRNA-VRCS) is increasing. We investigated the incidence of vaccine-related adverse events (VAEs), including myocarditis and pericarditis, in patients with mRNA-VRCS after receiving BNT162b2-Pfizer-BioNTech and mRNA-1273-Moderna vaccines., Materials and Methods: We retrospectively collected data on patients presenting with mRNA-VRCS who visited the outpatient clinic of two tertiary medical centers. Clinical characteristics, laboratory findings, echocardiographic findings, and electrocardiographic findings were evaluated. VAE was defined as myocarditis or pericarditis in patients after mRNA vaccination. Clinical outcomes during short-term follow-up, including emergency room (ER) visit, hospitalization, or death, were also assessed among the patients., Results: A total of 952 patients presenting with mRNA-VRCS were included in this study, with 89.7% receiving Pfizer-BioNTech and 10.3% receiving Moderna vaccines. The mean duration from vaccination to symptom was 5.6±7.5 days. VAEs, including acute myocarditis and acute pericarditis, were confirmed in 11 (1.2%) and 10 (1.1%) patients, respectively. The VAE group showed higher rates of dyspnea, echocardiography changes, and ST-T segment changes. During the short-term follow-up period of 3 months, the VAE group showed a higher hospitalization rate compared to the control group; there was no significant difference in ER visit ( p =0.320) or mortality rates ( p >0.999)., Conclusion: Amongst the patients who experienced mRNA-VRCS, the total incidence of VAEs, including acute myocarditis and pericarditis, was 2.2%. Patients with VAEs showed higher rates of dyspnea, echocardiographic changes, and ST-T segment changes compared to those without VAEs. With or without the cardiovascular events, the prognosis in patients with mRNA-VRCS was favorable., Competing Interests: The authors have no potential conflicts of interest to disclose., (© Copyright: Yonsei University College of Medicine 2024.)

The current COVID-19 mRNA vaccines were developed and applied for pandemic-emergent conditions. These vaccines use a small piece of the virus's genetic material (mRNA) to stimulate an immune response against COVID-19. However, their potential effects on individuals with chronic inflammatory conditions and vaccination routes remain questionable. Therefore, we investigated the effects of mRNA vaccines in a mouse model of chronic inflammation, focusing on their cardiac toxicity and immunogenicity dependent on the injection route. mRNA vaccine intravenous administration with or without chronic inflammation exacerbated cardiac pericarditis and myocarditis; immunization induced mild inflammation and inflammatory cytokine IL-1beta and IL-6 production in the heart. Further, IV mRNA vaccination induced cardiac damage in LPS chronic inflammation, particularly serum troponin I (TnI), which dramatically increased. IV vaccine administration may induce more cardiotoxicity in chronic inflammation. These findings highlight the need for further research to understand the underlying mechanisms of mRNA vaccines with chronic inflammatory conditions dependent on injection routes., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Jeon et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2n first appeared in Wuhan, China in 2019. Soon after, it was declared a pandemic by the World Health Organization. The health crisis imposed by a new virus and its rapid spread worldwide prompted the fast development of vaccines. For the first time in human history, two vaccines based on recombinant genetic material technology were approved for human use. These mRNA vaccines were applied in massive immunization programs around the world, followed by other vaccines based on more traditional approaches. Even though all vaccines were tested in clinical trials prior to their general administration, serious adverse events, usually of very low incidence, were mostly identified after application of millions of doses. Establishing a direct correlation (the cause-effect paradigm) between vaccination and the appearance of adverse effects has proven challenging. This review focuses on the main adverse effects observed after vaccination, including anaphylaxis, myocarditis, vaccine-induced thrombotic thrombocytopenia, Guillain-Barré syndrome, and transverse myelitis reported in the context of COVID-19 vaccination. We highlight the symptoms, laboratory tests required for an adequate diagnosis, and briefly outline the recommended treatments for these adverse effects. The aim of this work is to increase awareness among healthcare personnel about the serious adverse events that may arise post-vaccination. Regardless of the ongoing discussion about the safety of COVID-19 vaccination, these adverse effects must be identified promptly and treated effectively to reduce the risk of complications., (© 2024 The Author(s). Pharmacology Research & Perspectives published by British Pharmacological Society and American Society for Pharmacology and Experimental Therapeutics and John Wiley & Sons Ltd.)

Competing Interests: Declaration of competing interests The author declares that she has no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Background and Aims: The SARS-CoV-2 mRNA vaccines are associated with an increased risk of myocarditis. This association appears to be strongest in male adolescents and younger males and after the second dose. The aim was to evaluate the risk of myocarditis following SARS-CoV-2 mRNA booster vaccination in 12-to-39-year-olds., Methods: A multinational cohort study was conducted using nationwide register data in Denmark, Finland, Norway, and Sweden and comprising all 8.9 million individuals residing in each of the four countries. Participants were followed for an inpatient diagnosis of myocarditis. In each of the four countries, Poisson regression was used to estimate adjusted incidence rate ratios (IRRs) of myocarditis comparing vaccination schedules, with associated 95% confidence intervals (CIs). Country-specific results were combined in meta-analyses., Results: A total of 8.9 million residents were followed for 12 271 861 person-years and 1533 cases of myocarditis were identified. In 12-to-39-year-old males, the 28-day acute risk period following the third dose of BNT162b2 or mRNA-1273 was associated with an increased incidence rate of myocarditis compared to the post-acute risk period 28 days or more after the second dose [IRR 2.08 (95% CI 1.31-3.33) and 8.89 (2.26-35.03), respectively]. For females, the corresponding IRR was only estimable for BNT162b2, 3.99 (0.41-38.64). The corresponding absolute risks following the third dose of BNT162b2 and mRNA-1273 in males were 0.86 (95% CI 0.53-1.32) and 1.95 (0.53-4.99) myocarditis events within 28 days per 100 000 individuals vaccinated, respectively. In females, the corresponding absolute risks following the third dose of BNT162b2 were 0.15 (0.04-0.39) events per 100 000 individuals vaccinated. No deaths occurred within 30 days of vaccine-related cases., Conclusions: The results suggest that a booster dose is associated with increased myocarditis risk in adolescents and young adults. However, the absolute risk of myocarditis following booster vaccination is low., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Purpose: Although previous investigations revealed favourable in-hospital outcomes of COVID-19 vaccine-related myocarditis, the mid-term prognosis is still unclear. Hence, we aim to summarise existing evidence on the follow-up imaging and clinical findings in patients with COVID-19 vaccine-related myocarditis., Methods: We performed a systematic search in online databases using relevant key terms covering COVID-19 vaccine, myocarditis, follow-up, and cardiac MRI. We included all observational studies that reported cardiac MRI findings of patients with myocarditis following COVID-19 vaccination in both acute and follow-up phases. Data on clinical outcomes and cardiac MRI findings were extracted and pooled using a random-effect model., Results: A total of 27 studies (126 patients) met our eligibility criteria. At the time of follow-up, myocarditis symptoms were resolved in all patients, but abnormal electrocardiography and elevated troponin levels were detected in 18.7% and 3.8% of them, respectively. Median imaging follow-up times varied from 3 to 6.3 months. On follow-up cardiac MRI, the persistence of LGE was observed in 76% (95%CI: 62 to 85%), but its extension declined compared to the baseline in almost all patients. Persistent LGE was accompanied by myocardial edoema in six patients, and it was consistent with myocardial fibrosis (LGE without edoema) in the remaining cases. Mean changes (95%CI) of cardiac MRI left ventricular ejection fraction (LVEF) (%) was +2.97 (+1.59 to +4.34) from baseline., Conclusion: In conclusion, although most patients likely experience favourable clinical outcomes without serious complications, cardiac MRI abnormalities, mainly LGE, may persist in a notable proportion of them beyond the acute phase.

Background: To properly assess an association between vaccines and specific adverse events requires a comparison between the observed and background rates; however, studies in South Korea are currently limited. Therefore, in this study, we estimated the background incidence of anaphylaxis, myocarditis, pericarditis, Guillain-Barré syndrome (GBS), and mortality in South Korea., Methods: A retrospective cohort study was conducted using the National Sample Cohort (NSC) data. Using NSC, the background incidence rate was estimated by dividing the number of episodes during 2009-2019 by the total population by year and then multiplying by 100,000. Using Statistics Korea data, the background mortality rate was estimated by dividing the number of deaths, during 2009-2019 by the standard population for that year and then multiplying by 100,000. Using background mortality rates, we predicted mortality rates for 2021 using autoregressive integrated moving average models. Further, the expected mortality rates were compared with observed mortality rates., Results: The age-adjusted incidence rate (AIR) of anaphylaxis increased from 4.28 to 22.90 cases per 100,000 population (p = 0.003); myocarditis showed no significant increase, changing from 0.56 to 1.26 cases per 100,000 population (p = 0.276); pericarditis increased from 0.94 to 1.88 cases per 100,000 population (p = 0.005); and GBS increased from 0.78 to 1.21 cases per 100,000 population (p = 0.013). The age-adjusted mortality rate decreased from 645.24 to 475.70 deaths per 100,000 population (p <0.001). The 2021 observed/expected mortality rates for overall (ratio: 1.08, 95% confidence interval [CI]: 1.07-1.08), men (ratio: 1.07, 95% CI: 1.07-1.08), and women (ratio: 1.08, 95% CI: 1.07-1.09), were all significantly higher. When stratified by age group, those aged ≥80 (ratio: 1.16, 95% CI: 1.15-1.17), 60-69 (ratio: 1.11, 95% CI: 1.10-1.13), and 20-29 years old (ratio: 1.07, 95% CI: 1.02-1.13) were also significantly higher., Conclusion: Through the estimation of background rates related to anaphylaxis, myocarditis, pericarditis, GBS, and mortality, we established a reference point for evaluating the potential excess occurrence of adverse events following COVID-19 vaccination. This reference point serves as substantive evidence supporting the safety profile of COVID-19 vaccines., Competing Interests: All authors declare that they have no conflict of interest., (Copyright: © 2024 Jeong, Chun. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Objective: To investigate characteristics and management of children presenting with chest complaints to a tertiary paediatric ED post-mRNA COVID-19 vaccine., Methods: This was a retrospective medical record review with data linkage to the Australian Immunisation Register. The study setting was the Royal Children's Hospital, Melbourne, Australia. Children <18 years who had a troponin blood test performed in hospital within 14 days of receiving mRNA COVID-19 vaccination were included. Elevated troponin and myocarditis or pericarditis as per Brighton criteria was the primary outcome. Vaccination status, length of stay, investigations and clinical management were secondary outcomes., Results: Six hundred and ten patients had a troponin test in 13 months. After exclusion of trauma-related tests (n = 31), known cardiac patients (n = 75) and others (n = 145), 359 troponins were obtained due to chest complaints and related symptoms, with 283 troponins assessed to be mRNA vaccination-related. There was a temporal peak in presentations with a 30-fold monthly increase in troponin post-commencement of mRNA COVID-19 vaccines. In those with chest complaints following mRNA vaccination, mean age was 14 years and 50.4% were female. Fourteen out of 283 (5%) vaccine-related troponins were abnormal with 14 patients assessed to have vaccine-associated myocarditis. No patients had pericarditis., Conclusions: There was a large number of possible mRNA COVID-19 vaccine-related chest complaints presenting to the ED. Few patients had abnormal troponins or myocarditis., (© 2023 The Authors. Emergency Medicine Australasia published by John Wiley & Sons Australia, Ltd on behalf of Australasian College for Emergency Medicine.)

Background: Myocarditis and myopericarditis are well described adverse events of special interest (AESI) following COVID-19 vaccinations. Although reports are reassuring regarding initial clinical outcomes, information about longer term outcomes remains limited. We aimed to further this knowledge and report outcomes to 6 months post diagnosis from a single population cohort., Methods: Reports of myocarditis following COVID-19 vaccination were followed up by SAEFVIC (Surveillance of Adverse Events Following Vaccination in the Community), the state-wide vaccine safety service for Victoria, Australia. Confirmed myocarditis cases (Brighton Collaboration Criteria levels 1-3) were followed up via surveys at 1, 3 and 6 months post symptom onset. Responses received between 22 February 2021 and 30 September 2022 were analysed., Results: 87.5 % (N = 182) of eligible participants completed at least 1 survey report. 377 reports were analysed. 76.9 % of completed reports were from male patients. The median age of patients was 21 years [IQR: 16 to 32]. 54.8 % (n = 74) of survey reports at 6 months, reported ongoing symptoms. At all follow-up time points, females were significantly more likely to have ongoing symptoms. At 6 months, 51.9 % of male respondents reported symptom resolution compared to 22.6 % of female patients (p = 0.002). Females were also more likely to continue medication and have ongoing exercise restrictions. However, males were significantly more likely to have higher initial peak troponin results and abnormal initial cardiac imaging investigations., Conclusions: There appears to be a significant proportion of patients who experience ongoing symptoms to 6 months post onset amongst patients that experience these AESI. Male patients were more likely to report earlier and more complete symptom recovery, despite significantly higher average initial peak troponin. This difference in phenotypic presentation in females compared to males warrants further investigation and there is a need for longer term follow up data., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Background: Political orientation may play a formative role in perceptions of risk associated with COVID-19 vaccination including vaccine myocarditis (CVM). Whether political alignment of news sources plays a role in perception of this risk is unknown., Objective: We examined the relationship between political orientation of online media sites and aspects of reporting of CVM., Methods: Media sites were classified as "left" or "right" biased using the Allsides media bias rating report. For each site "COVID vaccine myocarditis" was searched in articles posted May 2021 to December 2022. Each search return was reviewed for the following: 1) Did it contain numerical data regarding CVM risk? 2) Did it report benefits of covid vaccination? 3) Did it mention covid infection-related myocarditis? Monthly reports of vaccine-related adverse events were obtained from the Vaccine Adverse Events Reporting System (VAERS)., Results: A total of 487 online reports regarding CVM were reviewed. Comparison of monthly report volumes from left vs. right biased media sources demonstrated significant correlation (r = 0.546, p = 0.013). Additionally monthly reporting of CVM was temporally related to monthly volume of VAERS reporting (r = 0.519, p = 0.023). These data suggest that monthly reporting volumes were driven by availability of information regarding CVM rather than media political alignment. Left biased media sources were significantly more likely to include numerical CVM data vs. right biased sources (76.6% vs. 24.3%, p<0.001) and likewise were more likely to include data supporting benefits of covid vaccination (85.1% vs. 21.7%. p<0.001). In contrast, there was no difference regarding mention of COVID-19 infection-related myocarditis (24.5% vs. 24.3%, p = 0.957)., Conclusion: Political orientation of online news sites was not associated with frequency of CVM reports but was related to report content, most notably whether reports included numerical data regarding CVM risk. These differential reporting characteristics may contribute to the relationship between political orientation and patient conceptualization of risk of CVM., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Matsumura et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The recognition of myocarditis as a rare side effect of SARS-CoV-2 mRNA vaccination has sparked a global debate on vaccine safety, especially in the realm of sports. The main proposed mechanisms in the pathogenesis of COVID-19 mRNA vaccination-associated myocarditis (C-VAM) are based on the activation of the innate- and adaptive immune system against a susceptible immune-genetic background, including the recognition of mRNA as an antigen by the immune system, molecular mimicry between SARS-CoV-2 spike glycoprotein and cardiac tissue antigens and inflammatory sex-hormone signalling. The relatively younger age of the athlete population hypothetically constellates an increased risk of C-VAM. A subgroup analysis in individuals under 40 years revealed a low incidence of myocarditis following COVID-19 mRNA vaccination when compared to positive SARS-CoV-2 tests. No confirmed cases of athletes experiencing cardiac complications after mRNA vaccination have been reported. Most athletes only reported mild side effects after COVID-19 vaccination. A small but statistically significant decrease in maximal oxygen consumption in recreational athletes occurred after BNT162b2 mRNA booster vaccine administration. The clinical relevance and temporality of which remain to be determined. Many speculative social media reports attribute sudden cardiac arrest/death (SCA/D) in athletes to mRNA vaccination. Large media outlets have thoroughly debunked these claims. There is currently no evidence to support the claim that COVID-19 mRNA vaccination increases the risk of myocardial sequelae or SCA/D in athletes. However, specific vaccine regimen selection and timing may be appropriate to prevent detrimental performance effects., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Cardiovascular complications after Pfizer-BioNTech COVID-19 (BNT) vaccination are a concern, especially in adolescents. We analyzed the risk factors for myocarditis after BNT vaccination., Methods: We used a special evaluation protocol for all patients aged 12-18 years who presented to our emergency department with cardiovascular symptoms after BNT vaccination., Results: A total of 195 patients (109 boys and 86 girls) were enrolled. Eleven (5.6%) patients presented with arrhythmia (arrhythmia group), 14 (7.2%) had a diagnosis of pericarditis/myocarditis (the peri/myocarditis group), and the remaining 170 were controls (no cardiac involvement). Chest pain (77.6%) was the most common symptom. The median time from vaccination to symptom onset was 3 days. In the peri/myocarditis group (13 myocarditis and 1 pericarditis), the median time to the peak troponin T level was 5 days after vaccination. Abnormal electrocardiographic changes, including ST-T changes and conduction blocks, were more commonly detected in the peri/myocarditis group (85.7% vs. 12.4% in the control group, p < 0.01). Echocardiography revealed normal ventricular function in all patients. Symptoms were resolved before discharge in all, with the median duration of hospital stay being 4 days. The electrocardiography was the most appropriate screening tool for myocarditis, with a sensitivity and specificity of 85.7% and 87.6%, respectively., Conclusion: Pericarditis or myocarditis was diagnosed in 7.2% of adolescents presenting to the emergency department with cardiovascular symptoms after BNT vaccination. In addition to the troponin T level, ECG change listed above can be used as a screening tool for vaccine-induced cardiac complications., Competing Interests: Declaration of competing interest The authors have no conflicts of interest relevant to this article., (Copyright © 2022 Formosan Medical Association. Published by Elsevier B.V. All rights reserved.)

Vaccines have had a tremendous impact on reducing the burden of infectious diseases; however, they have the potential to cause adverse events following immunization (AEFIs). Prelicensure clinical trials are limited in their ability to detect rare AEFIs that may occur in less than one per thousand individuals. While postmarketing surveillance systems have shown COVID-19 mRNA vaccines to be safe, they led to the identification of rare cases of myocarditis and pericarditis after COVID-19 vaccination that were not initially detected in clinical trials. In this narrative review, we highlight concepts of vaccine pharmacovigilance during mass vaccination campaigns and compare the approaches used in the context of myocarditis and pericarditis following COVID-19 vaccination to historical examples. We describe mechanisms of passive and active surveillance, their strengths and limitations, and how they interacted to identify and characterize the safety signal of myocarditis and pericarditis after COVID-19 mRNA vaccination. Articles were synthesized from a PubMed search using relevant keywords for articles published on vaccine surveillance systems and myocarditis and pericarditis after COVID-19 vaccination, as well as the authors' collections of relevant publications and grey literature reports. The global experience around the identification and monitoring of myocarditis and pericarditis after COVID-19 mRNA vaccination has provided important lessons for vaccine safety surveillance and highlighted its importance in maintaining public trust in mass vaccination programmes in a pandemic context., (© 2022 British Pharmacological Society.)

COVID vaccine-associated myocarditis was first identified in March 2021. There have been numerous case reports that detail the clinical course of paediatric patients older than age 12 with COVID vaccine-associated myocarditis. There are still very few reports of children between the ages of 5 and 11 with COVID vaccine-associated myocarditis. We present an 8 year- old with COVID vaccine-associated myocarditis after his second vaccination against SARS-CoV-2.

Acute myocarditis (especially) and pericarditis have been consistently associated with the administration of vaccines against SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), generating anxiety in the general population, uncertainty in the scientific community and obstacles to ambitious mass vaccination programs, especially in foreign countries. Like some of its European counterparts, the Portuguese Society of Cardiology (SPC), through its Studies Committee, decided to take a position on some of the most pressing questions related to this issue: (i) How certain are we of this epidemiological association? (ii) What is the probability of its occurrence? (iii) What are the pathophysiological bases of these inflammatory syndromes? (iv) Should their diagnosis, treatment and prognosis follow the same steps as for typical idiopathic or post-viral acute myopericarditis cases? (v) Is the risk of post-vaccine myocarditis great enough to overshadow the occurrence of serious COVID-19 disease in unvaccinated individuals? In addition, the SPC will issue clinical recommendations and offer its outlook on the various paths this emerging disease may take in the future., (Copyright © 2023 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.)

Objective: Past research shows that media coverage of medicine side effects can produce a nocebo response. New Zealand news media discussed myocarditis following the Pfizer COVID-19 vaccine. This study examined whether side effects mentioned in the media increased compared to control symptoms not mentioned., Methods: The study analysed 64,086 vaccine adverse reaction reports, retrieved from the medicine safety authority. Generalised linear regressions compared the side effect rate during three discrete periods of media reporting (August 2021, December 2021, April 2022) with the pre-media baseline rate. The outcomes were weekly reports of chest discomfort, monthly reports of chest, heart and breathing symptoms, and myocarditis, pericarditis, and anxiety. Control symptoms were fever, numbness, and musculoskeletal pain. Logistic regressions investigated factors associated with side effect reporting., Results: The reporting rate of chest discomfort was 190% greater in the five weeks after the first media item (p < .001). The monthly reporting rates of the symptoms mentioned in the media were significantly greater after the news coverage (ps ≤ 0.001). There was no effect of media on the control side effect fever (p = .06). There was an effect of media on myocarditis, pericarditis and anxiety (ps < 0.001). Anxiety, male gender, and younger age were significantly associated with side effects., Conclusion: The results indicate that a media-induced nocebo response occurred. This is most likely due to increased expectations and awareness of COVID-19 vaccine side effects, elevated symptom experience from anxiety, and consequently greater reporting of the symptoms in line with the media coverage., Competing Interests: Declaration of Competing Interest None., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Purpose of Review: To review myocarditis and pericarditis developing after COVID-19 vaccinations and identify the management strategies., Recent Findings: COVID-19 mRNA vaccines are safe and effective. Systemic side effects of the vaccines are usually mild and transient. The incidence of acute myocarditis/pericarditis following COVID-19 vaccination is extremely low and ranges 2-20 per 100,000. The absolute number of myocarditis events is 1-10 per million after COVID-19 vaccination as compared to 40 per million after a COVID-19 infection. Higher rates are reported for pericarditis and myocarditis in COVID-19 infection as compared to COVID-19 vaccines. COVID-19 vaccine-related inflammatory heart conditions are transient and self-limiting in most cases. Patients present with chest pain, shortness of breath, and fever. Most patients have elevated cardiac enzymes and diffuse ST-segment elevation on electrocardiogram. Presence of myocardial edema on T2 mapping and evidence of late gadolinium enhancement on cardiac magnetic resonance imaging are also helpful additional findings. Patients were treated with non-steroidal anti-inflammatory drugs and colchicine with corticosteroids reserved for refractory cases. At least 3-6 months of exercise abstinence is recommended in athletes diagnosed with vaccine-related myocarditis. COVID-19 vaccination is recommended in all age groups for the overall benefits of preventing hospitalizations and severe COVID-19 infection sequela., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Clinical course and outcomes of myocarditis after COVID-19 vaccination remain variable. We retrospectively collected data on patients &gt; 12 years old from 01/01/2021 to 12/30/2021 who received COVID-19 messenger RNA (mRNA) vaccination and were diagnosed with myocarditis within 60 days of vaccination. Myocarditis cases were based on case definitions by authors. We report on 238 patients of whom most were male (n = 208; 87.1%). The mean age was 27.4 ± 16 (range 12-80) years. Females presented at older ages (41.3 ± 21.5 years) than men 25.7 ± 14 years (p = 0.001). In patients &gt; 20 years of age, the mean duration from vaccination to symptoms was 4.8 days ± 5.5 days, but in &lt; 20, it was 3.0 ± 3.3 days (p = 0.04). Myocarditis occurred most commonly after the Pfizer-BioNTech mRNA vaccine (n = 183; 76.45) and after the second dose (n = 182; 80%). Symptoms started 3.95 ± 4.5 days after vaccination. The commonest symptom was chest pain (n = 221; 93%). Patients were treated with non-steroidal anti-inflammatory drugs (n = 105; 58.3%), colchicine (n = 38; 21.1%), or glucocorticoids (n = 23; 12.7%). About 30% of the patients had left ventricular ejection fraction but more than half recovered the on repeat imaging. Abnormal cardiac MRIs were common; 168 patients (96% of 175 patients that had MRI) had late gadolinium enhancement, while 120 patients (68.5%) had myocardial edema. Heart failure guideline-directed medical therapy use was common (n = 27; 15%). Eleven patients had cardiogenic shock; and 4 patients required mechanical circulatory support. Five patients (1.7%) died; of these, 3 patients had endomyocardial biopsy/autopsy-confirmed myocarditis. Most cases of COVID-19 vaccine myocarditis are mild. Females presented at older ages than men and duration from vaccination to symptoms was longer in patients &gt; 20 years. Cardiogenic shock requiring mechanical circulatory support was seen and mortality was low. Future studies are needed to better evaluate risk factors, and long-term outcomes of COVID-19 mRNA vaccine myocarditis., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: Myocarditis has been reported following the second dose of COVID-19 mRNA vaccination. Whether administration of additional doses of COVID-19 vaccines further increases the risk of myocarditis is unknown., Methods: We included individuals who received one to three doses of BNT162b2 or mRNA-1273 mRNA vaccine between 12/14/2020 and 2/18/2022. Myocarditis within 21 days of vaccine administration was identified using electronic medical records. Incidence rate ratios were calculated by comparing the observed incidence with the expected incidence from the same population during a 365-day baseline period., Results: Of 3,076,660 KPSC members who received at least one dose of COVID-19 mRNA vaccines, 2,916,739 (94.5%) received at least two doses, and 1,146,254 (47.0%) received three doses. The incidence rate ratio for myocarditis was 0.86 (95% CI 0.31-1.93) for the first dose, 4.22 (95% CI 2.63-6.53) for the second dose, and 2.61 (1.13-5.29) for the third dose. Most myocarditis cases following the second and third dose occurred within seven days of vaccination., Conclusion: Myocarditis was a rare event observed after the second or third dose of vaccination. Most cases presented within seven days of vaccination. The incidence of myocarditis following the third dose was not significantly higher than that observed after the second dose., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background: Both COVID-19 infection and COVID-19 vaccines have been associated with the development of myopericarditis. The objective of this study is to (1) analyse the rates of myopericarditis after COVID-19 infection and COVID-19 vaccination in Hong Kong, (2) compared to the background rates, and (3) compare the rates of myopericarditis after COVID-19 vaccination to those reported in other countries., Methods: This was a population-based cohort study from Hong Kong, China. Patients with positive RT-PCR test for COVID-19 between 1st January 2020 and 30th June 2021 or individuals who received COVID-19 vaccination until 31st August were included. The main exposures were COVID-19 positivity or COVID-19 vaccination. The primary outcome was myopericarditis., Results: This study included 11,441 COVID-19 patients from Hong Kong, four of whom suffered from myopericarditis (rate per million: 326; 95% confidence interval [CI] 127-838). The rate was higher than the pre-COVID-19 background rate in 2019 (rate per million: 5.5, 95% CI 4.1-7.4) with a rate ratio of 55.0 (95% CI 21.4-141). Compared to the background rate, the rate of myopericarditis among vaccinated subjects in Hong Kong was similar (rate per million: 5.5; 95% CI 4.1-7.4) with a rate ratio of 0.93 (95% CI 0.69-1.26). The rates of myocarditis after vaccination in Hong Kong were comparable to those vaccinated in the United States, Israel, and the United Kingdom., Conclusions: COVID-19 infection was associated with significantly higher rate of myopericarditis compared to the vaccine-associated myopericarditis., (© 2022. The Author(s).)

Temporal association between BNT162b2 mRNA COVID-19 vaccine and myocarditis (PCVM) has been reported. We herein present early and 6-month clinical follow-up and cardiac magnetic resonance imaging (CMR) of patients with PVCM. A retrospective collection of data from 15 patients with PCVM and abnormal CMR was performed. Clinical manifestation, laboratory data, hospitalizations, treatment protocols, and imaging studies were collected early (up to 2 months) and later. In nine patients, an additional CMR evaluation was performed 6 months after diagnosis. PCVM was diagnosed in 15 patients, mean age 17 ± 1 (median 17.2, range 14.9-19 years) years, predominantly in males. Mean time from vaccination to onset of symptoms was 4.4 ± 6.7 (median 3, range 0-28) days. All patients had CMR post diagnosis at 4 ± 3 (median 3, range 1-9) weeks, 4/5 patients had hyper enhancement on the T2 sequences representing edemaQuery, and 12 pathological Late glandolinium enhancement. A repeat scan performed after 5-6 months was positive for scar formation in 7/9 patients. PCVM is a rare complication, affecting predominantly males and appearing usually within the first week after administration of the second dose of the vaccine. It usually is a mild disease, with clinical resolution with anti-inflammatory treatment. Late CMR follow up demonstrated resolution of the edema in all patients, while some had evidence of residual myocardial scarring., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Competing Interests: Funding Support and Author Disclosures Dr Cavalcante has reported research support from Circle Cardiovascular Imaging and Siemens Healthineers. Dr Gössl has reported consulting for Abbott Vascular. Dr Shaw has reported that she has no relationships relevant to the contents of this paper to disclose.

Background There are limited data on the pattern and severity of myocardial injury in patients with COVID-19 vaccination-associated myocarditis. Purpose To describe myocardial injury following COVID-19 vaccination and to compare these findings to other causes of myocarditis. Materials and Methods In this retrospective cohort study, consecutive adult patients with myocarditis with at least one T1-based and at least one T2-based abnormality at cardiac MRI performed at a tertiary referral hospital from December 2019 to November 2021 were included. Patients were classified into one of three groups: myocarditis following COVID-19 vaccination, myocarditis following COVID-19 illness, and other myocarditis not associated with COVID-19 vaccination or illness. Results Of the 92 included patients, 21 (23%) had myocarditis following COVID-19 vaccination (mean age, 31 years ± 14 [SD]; 17 men; messenger RNA-1273 in 12 [57%] and BNT162b2 in nine [43%]). Ten of 92 (11%) patients had myocarditis following COVID-19 illness (mean age, 51 years ± 14; three men) and 61 of 92 (66%) patients had other myocarditis (mean age, 44 years ± 18; 36 men). MRI findings in the 21 patients with vaccine-associated myocarditis included late gadolinium enhancement (LGE) in 17 patients (81%) and left ventricular dysfunction in six (29%). Compared with other causes of myocarditis, patients with vaccine-associated myocarditis had a higher left ventricular ejection fraction and less extensive LGE, even after controlling for age, sex, and time from symptom onset to MRI. The most frequent location of LGE in all groups was subepicardial at the basal inferolateral wall, although septal involvement was less common in vaccine-associated myocarditis. At short-term follow-up (median, 22 days [IQR, 7-48 days]), all patients with vaccine-associated myocarditis were asymptomatic with no adverse events. Conclusion Cardiac MRI demonstrated a similar pattern of myocardial injury in vaccine-associated myocarditis compared with other causes, although abnormalities were less severe, with less frequent septal involvement and no adverse events over the short-term follow-up. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Raman and Neubauer in this issue.

Context.—: Myocarditis in adolescents has been diagnosed clinically following the administration of the second dose of an mRNA vaccine for coronavirus disease 2019 (COVID-19)., Objective.—: To examine the autopsy microscopic cardiac findings in adolescent deaths that occurred shortly following administration of the second Pfizer-BioNTech COVID-19 dose to determine if the myocarditis described in these instances has the typical histopathology of myocarditis., Design.—: Clinical and autopsy investigation of 2 teenage boys who died shortly following administration of the second Pfizer-BioNTech COVID-19 dose., Results.—: The microscopic examination revealed features resembling a catecholamine-induced injury, not typical myocarditis pathology., Conclusions.—: The myocardial injury seen in these postvaccine hearts is different from typical myocarditis and has an appearance most closely resembling a catecholamine-mediated stress (toxic) cardiomyopathy. Understanding that these instances are different from typical myocarditis and that cytokine storm has a known feedback loop with catecholamines may help guide screening and therapy.

Children and adolescents form a large proportion of societies and play an important role in the transmission of COVID-19. On the other hand, their education, mental and physical wellness, and safety are compromised which makes vaccination a crucial step to return to normal life. In the current systematic review, the COVID-19 vaccination was evaluated in a total of 50,148 children and adolescents in 22 published studies and 5,279 participants in two ongoing clinical trials. The study was registered in the PROSPERO with the ID# CRD42022303615. Data were collected about multiple vaccines including BNT162b2 (Pfizer), mRNA-1273 (Moderna), JNJ-78436735 (Johnson and Johnson), CoronaVac (Sinovac), BBIBP-CorV (Sinopharm), adenovirus type-5-vectored vaccine, ZyCov-D, and BBV152 (COVAXIN). The immune response and efficacy of such vaccines were 96% - 100% in healthy children and adolescents and were also acceptable in those with underlying diseases and suppressed immune systems. The current systematic review revealed favorable safety profiles of employed vaccines in children and adolescents; however, adverse reactions such as myocarditis and myopericarditis were reported which were transient and resolved entirely. Consequently, vaccinating children and adolescents aged 2 - 21 years old is beneficial to abort the COVID-19 pandemic. Moreover, the risk-benefit assessments revealed favorable results for vaccinating children and adolescents, especially those with underlying diseases and immunosuppressed conditions, alongside adults to prevent transmission, severe infection, negative outcomes, and new variants formation. Also, according to the meta-analysis, the efficacy and immune response of vaccines after the first and second doses were 91% and 92%, respectively. Meanwhile, overall immune response for all vaccines was 95% and 91% for Pfizer vaccine., (Copyright © 2022. Published by Elsevier B.V.)

Purpose: How completely do hospital discharge diagnoses identify cases of myopericarditis after an mRNA vaccine?, Methods: We assembled a cohort 12-39 year-old patients, insured by Kaiser Permanente Northwest, who received at least one dose of an mRNA vaccine (Pfizer-BioNTech or Moderna) between December 2020 and October 2021. We followed them for up to 30 days after their second dose of an mRNA vaccine to identify encounters for myocarditis, pericarditis or myopericarditis. We compared two identification methods: A method that searched all encounter diagnoses using a brief text description (e.g., ICD-10-CM code I40.9 is defined as 'acute myocarditis, unspecified'). We searched the text description of all inpatient or outpatient encounter diagnoses (in any position) for "myocarditis" or "pericarditis." The other method was developed by the Centers for Disease Control and Prevention's Vaccine Safety Datalink (VSD), which searched for emergency department visits or hospitalizations with a select set of discharge ICD-10-CM diagnosis codes. For both methods, two physicians independently reviewed the identified patient records and classified them as confirmed, probable or not cases using the CDC's case definition., Results: The encounter methodology identified 14 distinct patients who met the confirmed or probable CDC case definition for acute myocarditis or pericarditis with an onset within 21 days of receipt of COVID-19 vaccination. When we extended the search for relevant diagnoses to 30 days since vaccination, we identified two additional patients (for a total of 16 patients) who met the case definition for acute myocarditis or pericarditis, but those patients had been misdiagnosed at the time of their original presentation. Three of these patients had an ICD-10-CM code of I51.4 "Myocarditis, Unspecified;" that code was omitted by the VSD algorithm (in the late fall of 2021). The VSD methodology identified 11 patients who met the CDC case definition for acute myocarditis or pericarditis. Seven (64%) of the 11 patients had initial care for myopericarditis outside of a KPNW facility and their diagnosis could not be ascertained by the VSD methodology until claims were submitted (median delay of 33 days; range of 12-195 days). Among those who received a second dose of vaccine (n = 146 785), we estimated a risk as 95.4 cases of myopericarditis per million second doses administered (95% CI, 52.1-160.0)., Conclusion: We identified additional valid cases of myopericarditis following an mRNA vaccination that would be missed by the VSD's search algorithm, which depends on select hospital discharge diagnosis codes. The true incidence of myopericarditis is markedly higher than the incidence reported to US advisory committees in the fall of 2021. The VSD should validate its search algorithm to improve its sensitivity for myopericarditis., (© 2022 John Wiley & Sons Ltd.)

Myocarditis is an established but rare adverse event following administration of messenger RNA-based coronavirus disease 2019 (COVID-19) vaccines and is most common in male adolescents and young adults. Symptoms typically develop within a few days of vaccine administration. Most patients have mild abnormalities on cardiac imaging with rapid clinical improvement with standard treatment. However, longer term follow-up is needed to determine whether imaging abnormalities persist, to evaluate for adverse outcomes, and to understand the risk associated with subsequent vaccination. The purpose of the review is to evaluate the current literature related to myocarditis following COVID-19 vaccination, including the incidence, risk factors, clinical course, imaging findings, and proposed pathophysiologic mechanisms., Competing Interests: Disclosure Dr K. Hanneman has received speaker’s honorarium from Sanofi-Genzyme, Amicus, and Medscape. Dr P. Thavendiranathan has received speaker’s honorarium from Amgen, Boehringer Ingelheim-Lilly, and Takeda. Dr J.A. Udell has served as a consultant or speaker for AstraZeneca, Bayer, Boehringer Ingelheim-Lilly, Janssen, Merck, Novartis, and Sanofi and has received research grants from AstraZeneca, Amgen, Bayer, Boehringer Ingelheim-Lilly, and Janssen., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Canadian and international data suggest the risk of myocarditis and/or pericarditis is elevated during the week after mRNA COVID-19 vaccination, particularly in younger age groups, in males, and after second doses., Objectives: This article examines whether there is a product-specific difference in the risk for myocarditis and/or pericarditis between the two mRNA vaccines administered in Canada: BNT162b2 (Pfizer-BioNTech Comirnaty) and mRNA-1273 (Moderna Spikevax)., Materials and Methods: Reporting rates of myocarditis and/or pericarditis were calculated from reports received by the Canadian Adverse Events Following Immunization Surveillance System from December 2020-March 2022. Excess cases and attributable incidence among individuals aged 18-39 were estimated for each vaccine in comparison with background rates from 2015 to 2019. Head-to-head comparisons used Poisson regression, conditioned on week of vaccine administration, to estimate rate ratios for the week after mRNA-1273 vaccination versus the week after BNT162b2, by age and sex as well as overall. Analyses were restricted to May 30-March 13, 2021, when heightened media awareness was unlikely to have affected reporting rates for the two products differentially., Results: In 18-29 year-old males who received a second dose of mRNA COVID-19 vaccine, attributable risk of myocarditis and/or pericarditis was found to be 5.69 (95% CI: 4.07 - 7.95; p < 0.001) times higher among mRNA-1273 recipients (n = 106) as compared to BNT162b2 recipients (n = 33). In the same group, Poisson regression modelling estimated that the risk of myocarditis and/or pericarditis was 4.72 (p-value = <0.001) times higher after mRNA-1723 compared to BNT162b2 vaccination., Conclusions: The risk of myocarditis and/or pericarditis is higher after mRNA-1723 vaccination than BNT162b2 vaccination in those aged 18-39 years, especially in males aged 18-29 years, where the risk is several times higher., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Crown Copyright © 2022. Published by Elsevier Ltd. All rights reserved.)

Background: Rapid deployment of COVID-19 vaccines is challenging for safety surveillance, especially on adverse events of special interest (AESIs) that were not identified during the pre-licensure studies. This study evaluated the risk of hospitalisations for predefined diagnoses among the vaccinated population in Malaysia., Methods: Hospital admissions for selected diagnoses between 1 February 2021 and 30 September 2021 were linked to the national COVID-19 immunisation register. We conducted self-controlled case-series study by identifying individuals who received COVID-19 vaccine and diagnosis of thrombocytopenia, venous thromboembolism, myocardial infarction, myocarditis/pericarditis, arrhythmia, stroke, Bell's Palsy, and convulsion/seizure. The incidence of events was assessed in risk period of 21 days postvaccination relative to the control period. We used conditional Poisson regression to calculate the incidence rate ratio (IRR) and 95% confidence interval (CI) with adjustment for calendar period., Results: There was no increase in the risk for myocarditis/pericarditis, Bell's Palsy, stroke, and myocardial infarction in the 21 days following either dose of BNT162b2, CoronaVac, and ChAdOx1 vaccines. A small increased risk of venous thromboembolism (IRR 1.24; 95% CI 1.02, 1.49), arrhythmia (IRR 1.16, 95% CI 1.07, 1.26), and convulsion/seizure (IRR 1.26; 95% CI 1.07, 1.48) was observed among BNT162b2 recipients. No association between CoronaVac vaccine was found with all events except arrhythmia (IRR 1.15; 95% CI 1.01, 1.30). ChAdOx1 vaccine was associated with an increased risk of thrombocytopenia (IRR 2.67; 95% CI 1.21, 5.89) and venous thromboembolism (IRR 2.22; 95% CI 1.17, 4.21)., Conclusion: This study shows acceptable safety profiles of COVID-19 vaccines among recipients of BNT162b2, CoronaVac, and ChAdOx1 vaccines. This information can be used together with effectiveness data for risk-benefit analysis of the vaccination program. Further surveillance with more data is required to assess AESIs following COVID-19 vaccination in short- and long-term., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Background: Myocarditis and pericarditis following the Coronavirus Disease 2019 (COVID-19) mRNA vaccines administration have been reported, but their frequency is still uncertain in the younger population. This study investigated the association between Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) mRNA vaccines, BNT162b2, and mRNA-1273 and myocarditis/pericarditis in the population of vaccinated persons aged 12 to 39 years in Italy., Methods and Findings: We conducted a self-controlled case series study (SCCS) using national data on COVID-19 vaccination linked to emergency care/hospital discharge databases. The outcome was the first diagnosis of myocarditis/pericarditis between 27 December 2020 and 30 September 2021. Exposure risk period (0 to 21 days from the vaccination day, subdivided in 3 equal intervals) for first and second dose was compared with baseline period. The SCCS model, adapted to event-dependent exposures, was fitted using unbiased estimating equations to estimate relative incidences (RIs) and excess of cases (EC) per 100,000 vaccinated by dose, age, sex, and vaccine product. Calendar period was included as time-varying confounder in the model. During the study period 2,861,809 persons aged 12 to 39 years received mRNA vaccines (2,405,759 BNT162b2; 456,050 mRNA-1273); 441 participants developed myocarditis/pericarditis (346 BNT162b2; 95 mRNA-1273). Within the 21-day risk interval, 114 myocarditis/pericarditis events occurred, the RI was 1.99 (1.30 to 3.05) after second dose of BNT162b2 and 2.22 (1.00 to 4.91) and 2.63 (1.21 to 5.71) after first and second dose of mRNA-1273. During the [0 to 7) days risk period, an increased risk of myocarditis/pericarditis was observed after first dose of mRNA-1273, with RI of 6.55 (2.73 to 15.72), and after second dose of BNT162b2 and mRNA-1273, with RIs of 3.39 (2.02 to 5.68) and 7.59 (3.26 to 17.65). The number of EC for second dose of mRNA-1273 was 5.5 per 100,000 vaccinated (3.0 to 7.9). The highest risk was observed in males, at [0 to 7) days after first and second dose of mRNA-1273 with RI of 12.28 (4.09 to 36.83) and RI of 11.91 (3.88 to 36.53); the number of EC after the second dose of mRNA-1273 was 8.8 (4.9 to 12.9). Among those aged 12 to 17 years, the RI was of 5.74 (1.52 to 21.72) after second dose of BNT162b2; for this age group, the number of events was insufficient for estimating RIs after mRNA-1273. Among those aged 18 to 29 years, the RIs were 7.58 (2.62 to 21.94) after first dose of mRNA-1273 and 4.02 (1.81 to 8.91) and 9.58 (3.32 to 27.58) after second dose of BNT162b2 and mRNA-1273; the numbers of EC were 3.4 (1.1 to 6.0) and 8.6 (4.4 to 12.6) after first and second dose of mRNA-1273. The main study limitations were that the outcome was not validated through review of clinical records, and there was an absence of information on the length of hospitalization and, thus, the severity of the outcome., Conclusions: This population-based study of about 3 millions of residents in Italy suggested that mRNA vaccines were associated with myocarditis/pericarditis in the population younger than 40 years. According to our results, increased risk of myocarditis/pericarditis was associated with the second dose of BNT162b2 and both doses of mRNA-1273. The highest risks were observed in males of 12 to 39 years and in males and females 18 to 29 years vaccinated with mRNA-1273. The public health implication of these findings should be considered in the light of the proven mRNA vaccine effectiveness in preventing serious COVID-19 disease and death., Competing Interests: I have read the journal’s policy and the author of this manuscript have the following competing interests: in the last 36 months, GT coordinated a pharmacoepi team at the University of Messina till Oct 2020 and currently at the academic spin-off INSPIRE that received research grants from PTC Therapeutics, Kiowa Kirin, Chiesi, Daiichi Sankyo for the conduct of observational studies on topics not related to the paper; GT participated to Advisory Board/interview sponsored by Eli Lilly, Amgen, Sanofi, SOBI, Gilead, ABBvie, Verpora and Daiichi Sankyo on topics not related to the paper.

There have been several local and systemic adverse events associated with mRNA COVID-19 vaccines. Pericarditis, myocarditis and myocardial infarction are examples of cardiac complications related to these vaccines. In this article, we conducted a systematic review of case reports and case series to identify the clinical profile, investigations, and management of reported cardiac complications post-mRNA COVID-19 vaccines. We systematically searched PubMed, Scopus, Web of Science, and Google Scholar, as well as the medRxiv preprint server, with terms including: 'SARS-CoV-2', 'COVID-19', 'messenger RNA vaccine*', 'mRNA-1273 vaccine', 'BNT162 vaccine', 'myocarditis', 'pericarditis', 'stroke' and 'Myocardial Ischemia' up to 25 September 2021. Studies were excluded if they were not case reports or case series, or reported cases from non-mRNA vaccines. Case reports and case series were included that investigated the potential cardiac complications associated with mRNA COVID-19 vaccines. The JBI checklist was used to assess quality and data synthesis was conducted using a qualitative methodology called narrative synthesis. Sixty-nine studies, including 43 case reports and 26 case series, were included. Myocarditis/myopericarditis and pericarditis were the most common adverse events among the 243 reported cardiac complications, post mRNA COVID-19 vaccination. Males with a median age of 21 years had the highest frequency of myocarditis. Almost three quarters (74.4%) of cases with myocarditis had received the BNT162b2 vaccine and 87.7% had received the second dose of the vaccine. Chest pain (96.1%) and fever (38.2%) were the most common presentations. CK-MB, troponin, and NT-proBNP were elevated in 100%, 99.5% and 78.3% of subjects, respectively. ST-segment abnormality was the most common electrocardiogram feature. Cardiac magnetic resonance imaging, which is the gold-standard approach for diagnosing myocarditis, was abnormal in all patients diagnosed with myocarditis. Non-steroidal anti-inflammatory drugs were the most prescribed medication for the management of myocarditis. Apart from inflammatory conditions, some rare cases of Takotsubo cardiomyopathy, myocardial infarction, myocardial infarction with non-obstructive coronary arteries, and isolated tachycardia were also reported following immunisation with mRNA COVID-19 vaccines. We acknowledge that only reviewing case reports and case series studies is one potential limitation of our study. We found that myocarditis was the most commonly reported adverse cardiac event associated with mRNA COVID-19 vaccines, which presented as chest pain with a rise in cardiac biomarkers. Further large-scale observational studies are recommended., (© 2021 John Wiley & Sons Ltd.)

Introduction : COVID-19, the infectious disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), often presents with a spectrum of symptoms at varying levels of severity, ranging from asymptomatic patients to those with fatal complications, such as myocarditis. With increased availability of COVID-19 vaccines, the awareness of possible side effects has expanded as reports surface. This study reviewed cases of myocarditis following COVID-19 vaccination and with existing literature on COVID-19 infection-induced myocarditis to compare clinical courses and analyze possible mechanisms of action. Methods : A systematic review of literature was conducted to identify published case reports (as of February 3, 2022) pertaining to the development of myocarditis following COVID-19 vaccination with either Pfizer or Moderna for an in-depth analysis. Additional subgroup analyses were conducted based on age, past medical history, vaccine manufacturer, and dose number. Results : There were 53 eligible case reports that were included in this study. Patients were mostly male with a median age of 24 years, and the most reported symptom upon presentation was chest pain. Seventy percent of the cases involved the Pfizer vaccine with a majority of myocarditis developing subsequent to second dose. Resolution of symptoms was achieved in all but one patient. Clinical severity, as measured primarily by left ventricular ejection fraction, appeared to be worse among adult patients than pediatric, as well as for patients with comorbidities. Conclusion : This study revealed an observable association between COVID-19 vaccines and myocarditis. However, the clinical course and prognosis seem favorable and less prevalent than those conferred from natural infection., (Copyright ©2022, Yale Journal of Biology and Medicine.)

We report a rare case of severe myopericarditis in a healthy man in his 20s after the third dose of an mRNA COVID-19 vaccine. His symptoms and troponinemia resolved with a beta-blocker in addition to standard anti-inflammatory therapy, highlighting the utility of multimodal therapy., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Pfizer-BioNTech COVID-19 (BNT162b2) conferred a high level of protection against Covid-19 with a proven short-term safety profile. Although cases of vaccine-associated myopericarditis have been reported, the existence of rhabdomyolysis without myocarditis has not yet been published. A 16-year-old, healthy male patient, who did not use any herbal or illegal drugs before, was admitted with muscle pain that developed after the second dose of BNT162b2 vaccine. Cardiac examination and heart enzymes were normal and the patient had significantly higher creatinine kinase levels. The patient, whose enzymes returned to normal with only force hydration therapy, recovered without complications. Reporting the side effects of the vaccine, which has a short history of application to large populations, is of vital importance in the conduct of vaccine development studies and in identifying the risky group in terms of side effects., (© 2022 The College of Medicine and the Medical Association of Malawi.)