Myocarditis is the most salient serious adverse event following messenger RNA-based Covid-19 vaccines. The highest risk is observed after the second dose compared to the first, whereas the level of risk associated with more distant booster doses seems to lie in between. We aimed to assess the relation between dosing interval and the risk of myocarditis, for both the two-dose primary series and the third dose (first booster).
View Article and Find Full Text PDFBackground: COVID-19 vaccination has been inconsistently associated with an increased risk of heavy menstrual bleeding in previous studies. This study aimed to assess the risk of heavy menstrual bleeding requiring hospital care following COVID-19 vaccination according to the number of doses received and the time elapsed since vaccination.
Methods: Using comprehensive data of the French National Health Data System, we carried out a case-control study.
Importance: Although patients with myocarditis after COVID-19 mRNA vaccination appear to have a good prognosis near hospital discharge, their longer-term prognosis and management remain unknown.
Objective: To study the cardiovascular complications of post-COVID-19 mRNA vaccination myocarditis and other types of myocarditis during an 18-month follow-up, as well as disease management based on a study of the frequency of medical procedures and drug prescriptions.
Design, Setting, And Participants: In this cohort study based on the French National Health Data System, all individuals aged 12 to 49 years hospitalized for myocarditis in France between December 27, 2020, and June 30, 2022, were identified.
Background: In spite of major effectiveness, a residual risk after COVID-19 primary vaccination was identified, in particular, for vulnerable individuals of advanced age or with comorbidities. Less is known about the Omicron period in people protected by a booster dose. We aimed to identify the characteristics associated with severe COVID-19 during the Omicron period in a population that had received a booster dose in France and to compare differences with the previous periods of the pandemic.
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