@article {Chenge001472, author = {Daryl R Cheng and Hazel J Clothier and Hannah J Morgan and Emma Roney and Priya Shenton and Nicholas Cox and Bryn O Jones and Silja Schrader and Nigel W Crawford and Jim P Buttery}, editor = {, and , and Goldsmith, Greta and Hikmat, Samar and Osowicki, Josh and Phuong, Linny and Addison, Mel and Dempsey, Louise and Harris, Adele and Lewis, Georgie and Penak, Bianca and Voss, Laura and Craft, Jaimee and Scott, Victoria and Tham, Lois and Power, Anna and Blow, Ngaree and Sawmy, Elise Virah and Duckworth, Eleanor and Wolthuizen, Michelle and Tenneti, Naveen and White, Nick and Heland, Melodie and Gordon, Sally and Standish, Jane and McCloskey, Kathleen and Doherty, Brooke and Fleming, Catie and Carr, Jeremy and O{\textquoteright}Brien, Matthew and Loke, Paxton and Earley, Ciara and Tran, David and O{\textquoteright}Dea, Shane and Cox, Lianne and Asakawa, Yoko and Lazzaro, Teresa and Perrett, Kirsten and Tosif, Shidan and Uahwatanasakul, Wonie}, title = {Myocarditis and myopericarditis cases following COVID-19 mRNA vaccines administered to 12{\textendash}17-year olds in Victoria, Australia}, volume = {6}, number = {1}, elocation-id = {e001472}, year = {2022}, doi = {10.1136/bmjpo-2022-001472}, publisher = {BMJ Specialist Journals}, abstract = {Importance COVID-19 mRNA vaccine-associated myocarditis has previously been described; however specific features in the adolescent population are currently not well understood.Objective To describe myocarditis adverse events following immunisation reported following any COVID-19 mRNA vaccines in the adolescent population in Victoria, Australia.Design Statewide, population-based study.Setting Surveillance of Adverse Events Following Vaccination in the Community (SAEFVIC) is the vaccine-safety service for Victoria, Australia.Participants All SAEFVIC reports of myocarditis and myopericarditis in 12{\textendash}17-year-old COVID-19 mRNA vaccinees submitted between 22 February 2021 and 22 February 2022, as well as accompanying diagnostic investigation results where available, were assessed using Brighton Collaboration criteria for diagnostic certainty.Exposures Any mRNA COVID-19 vaccine.Main outcomes/Mmeasure Confirmed myocarditis as per Brighton Collaboration criteria (levels 1{\textendash}3).Results Clinical review demonstrated definitive (Brighton level 1) or probable (level 2) diagnoses in 75 cases. Confirmed myocarditis reporting rates were 8.3 per 100 000 doses in this age group. Cases were predominantly male (n=62, 82.7\%) and post dose 2 (n=61, 81.3\%). Rates peaked in the 16{\textendash}17-year-old age group and were higher in males than females (17.7 vs 3.9 per 100 000, p=\<0.001).The most common presenting symptoms were chest pain, dyspnoea and palpitations. A large majority of cases who had a cardiac MRI had abnormalities (n=33, 91.7\%). Females were more likely to have ongoing clinical symptoms at 1-month follow-up (p=0.02).Conclusion Accurate evaluation and confirmation of episodes of COVID-19 mRNA vaccine-associated myocarditis enabled understanding of clinical phenotypes in the adolescent age group. Any potential vaccination and safety surveillance policies needs to consider age and gender differences.No data are available.}, URL = {https://bmjpaedsopen.bmj.com/content/6/1/e001472}, eprint = {https://bmjpaedsopen.bmj.com/content/6/1/e001472.full.pdf}, journal = {BMJ Paediatrics Open} }