A narrative review of vaccine pharmacovigilance during mass vaccination campaigns: Focus on myocarditis and pericarditis after COVID-19 mRNA vaccination.

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.

Ventricular Arrhythmia and COVID-19 Vaccine-associated Myocarditis.

17-year-old male presented with COVID-19 vaccine-associated myocarditis. Six months later, due to chest discomfort with exercise, the patient underwent an exercise stress test that revealed a 3-beat run of nonsustained ventricular tachycardia at 230 bpm at peak exercise. The long-term outcomes of COVID-19 vaccine-associated myocarditis are unclear. This patient had nonsustained ventricular tachycardia over 6 months after diagnosis.

The Incidence of Myocarditis Following an Influenza Vaccination: A Population-Based Observational Study.

BACKGROUND AND OBJECTIVE: Recently, studies have pointed to a link between coronavirus disease 2019 vaccinations and myocarditis. Myocarditis following an influenza vaccine has been sporadically reported. However, it is not known whether this adverse event occurs among elderly individuals who have received influenza vaccines. We used a population-based database and a self-controlled case-series design to estimate the incidence of myocarditis following an influenza vaccination. METHODS: Data were extracted from Taiwan's National Health Insurance Research Database. The study population consisted of elderly people aged ≥ 65 years who had de novo myocarditis, which required hospitalization, within 6 months after receiving an influenza vaccination between 2003 and 2017. The first 1-7, 1-14, and 1-42 days after vaccination were defined as risk intervals, and the other periods were defined as control intervals. Poisson regression was used to calculate the incidence rate ratio for myocarditis between the risk and control periods. RESULTS: Within 180 days following a vaccination, 191 people were hospitalized for myocarditis among 19,678,904 people. In comparison with control intervals, the incidence rate ratios of an admission for myocarditis for days 1-7, 1-14, and 1-42 were 0.80 (95% confidence interval 0.36-1.81), 0.72 (95% confidence interval 0.39-1.32), and 0.73 (95% confidence interval 0.50-1.05), respectively. Subgroup analyses by sex, age, Charlson Comorbidity Index scores, and comorbidities did not yield significant differences in the incidence rate ratio. CONCLUSIONS: Regardless of the post-vaccination time and underlying baseline characteristics, the incidence risk of myocarditis is not significantly increased in the elderly following an influenza vaccination.

Anti-SARS-CoV-2 vaccine-induced myocarditis - real but, in general, rare and mild: A consensus statement from the Studies Committee of the Portuguese Society of Cardiology.

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.

Management of cardiovascular symptoms after Pfizer-BioNTech COVID-19 vaccine in teenagers in the emergency department.

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.

Post-COVID mRNA vaccine myocarditis in children: report of two cases.

The SARS-COV-2 pandemic led to the development of several vaccinations to contain the disease. The Pfizer-BioNTech COVID-19 (BNT162b2) vaccine was recommended on May 2021 for use in children above 12 years and older. The vaccine is safe, well tolerated and highly effective. Initial reports showed no serious adverse events; however, cases of myocarditis in young healthy male adolescents have been reported. We report two cases of myocarditis/perimyocarditis who presented with short history of chest pain following administration of the second dose of the MRN COVID-19 vaccine.

Comparison of Multisystem Inflammatory Syndrome in Children-Related Myocarditis, Classic Viral Myocarditis, and COVID-19 Vaccine-Related Myocarditis in Children.

Background Although rare, classic viral myocarditis in the pediatric population is a disease that carries significant morbidity and mortality. Since 2020, myocarditis has been a common component of multisystem inflammatory syndrome in children (MIS-C) following SARS-CoV-2 infection. In 2021, myocarditis related to mRNA COVID-19 vaccines was recognized as a rare adverse event. This study aims to compare classic, MIS-C, and COVID-19 vaccine-related myocarditis with regard to clinical presentation, course, and outcomes. Methods and Results In this retrospective cohort study, we compared patients aged <21 years hospitalized at our institution with classic viral myocarditis from 2015 to 2019, MIS-C myocarditis from March 2020 to February 2021, and vaccine-related myocarditis from May 2021 to June 2021. Of 201 total participants, 43 patients had classic myocarditis, 149 had MIS-C myocarditis, and 9 had vaccine-related myocarditis. At presentation, ejection fraction was lowest for those with classic myocarditis, with ejection fraction <55% present in 58% of patients. Nearly all patients with MIS-C myocarditis (n=139, 93%) and all patients with vaccine-related myocarditis (n=9, 100%) had normal left ventricular ejection fraction at the time of discharge compared with 70% (n=30) of the classic myocarditis group (P<0.001). At 3 months after discharge, of the 21 children discharged with depressed ejection fraction, none of the 10 children with MIS-C myocarditis had residual dysfunction compared with 3 of the 11 (27%) patients in the classic myocarditis group. Conclusions Compared with classic myocarditis, those with MIS-C myocarditis had better clinical outcomes, including rapid recovery of cardiac function. Patients with vaccine-related myocarditis had prompt resolution of symptoms and improvement of cardiac function.

Case Report of COVID-19 mRNA Vaccine-Associated Myocarditis.

INTRODUCTION: We present a case report highlighting a single patient out of 3 who developed myocarditis within days after receiving Pfizer and Moderna COVID-19 mRNA vaccines. CASE PRESENTATION: A 19-year-old male was admitted to our hospitalist service with substernal chest pain that was sharp, constant, and varied with position. He had received his second dose of the Pfizer-BioNTech COVID-19 vaccine (Pfizer vaccine) 2 days prior. Electrocardiogram was consistent with pericarditis. He had persistently elevated troponins and globally reduced systolic function by echocardiogram, which was consistent with myocarditis. He received colchicine, ibuprofen, and proton pump inhibitors with a resolution of symptoms. After 32 days, follow-up echocardiogram had returned to normal, and his symptoms had resolved completely. DISCUSSION: Given the onset of symptoms after the second dose of vaccine and our review of similar cases in the literature, it seems likely the patient's myopericarditis was caused by the vaccine. Rare complications of new vaccines given to millions of people are rapidly identified by the Vaccine Adverse Event Reporting System. CONCLUSIONS: The identification of myopericarditis as a complication of mRNA vaccines will need further study to understand the pathophysiology, incidence, and prevalence in specific age groups and biological sexes.

Two Cases of Acute Myocarditis in Young Male Adults After mRNA Vaccines Against COVID-19: Similarities and Differences.

Background: The advent of the new coronavirus SARS-CoV-2 has created unprecedented situations, both in terms of health and socio-economic level, worldwide. The emergence of vaccines against this highly contagious virus has raised hopes for its effective inhibition. The efficacy of vaccines, in more than a year of their application in clinical practice, is indisputable, both in terms of reducing serious hospitalizations and deaths, especially in high-risk populations. As with any new medication, the quest and investigation for side effects are reasonable. Myocarditis is one of the extremely rare side effects reported in mRNA vaccines, especially in young males. Case presentation: We present two cases of myocarditis that occurred in our hospital in a short time between them and compare them point by point to identify similarities and differences in order to draw conclusions about the severity of this side effect and its outcome. Conclusion: The benefits of vaccination against Covid-19 outweigh possible untoward effects and especially myocarditis. Health workers must close monitor the vaccinated patients for possible future cardiovascular complications.