Acute Myocardial Injury Following COVID-19 Vaccination

Adverse Events and Safety Profile of the COVID-19 Vaccines in Adolescents: Safety Monitoring for Adverse Events Using Real-World Data

A COVID-19 vaccine BNT162b2 (Pfizer-BioNTech) has recently been authorized for adolescents in the US. However, the impact of adverse events on adolescents after vaccination has not been fully investigated. To assess the safety of the COVID-19 vaccine in adolescents, the incidence of adverse events (AEs) in adolescents and adults was compared after vaccination. We included 6304 adolescents (68.14 per 100,000 people) who reported adverse events using vaccine adverse event reporting system (VAERS) data from 10 May 2021 to 30 September 2021. The mean age was 13.6 ± 1.1 years and women (52.7%) outnumbered men. We analyzed severe and common adverse events in response to the COVID-19 vaccine among 6304 adolescents (68.14 per 100,000 people; 52% female; mean age, 13.6 ± 1.1 years). The risk of myocarditis or pericarditis among adolescents was significantly higher in men than in women (OR = 6.61, 95% CI = 4.43 to 9.88; p < 0.001), with a higher frequency after the second dose of the vaccine (OR = 8.52, 95% CI = 5.79 to 12.54; p < 0.001). In addition, severe adverse events such as multisystem inflammatory syndromes, where the incidence rate per 100,000 people was 0.11 (n = 10), and the relative risk was 244.3 (95% CI = 31.27 to 1908.38; p < 0.001), were significantly higher in adolescents than in adults. The risk of the inflammatory response to the COVID-19 vaccine, including myocarditis, pericarditis, or multisystem inflammatory syndromes, was significantly higher in men than in women, with a higher frequency in adolescents than in adults. The inflammation-related AEs may require close monitoring and management in adolescents.

Change of blood viscosity after COVID-19 vaccination: estimation for persons with underlying metabolic syndrome

The COVID-19 vaccine is a new vaccine aiming at control of COVID-19 pandemic. This new vaccine is useful for pandemic management, however, an important consideration is on its safety. Thrombosis is a problem might occur after COVID-19 vaccination and the increased blood viscosity is a pathomechanism. Here, the authors estimate on blood viscosity change after COVID-19 vaccination for vaccine recipient with underlying metabolic syndrome. Based on mathematical modelling and simulating technique, the authors estimate the change of blood viscosity after COVID-19 vaccination for persons with underlying metabolic syndrome. According to the estimation, blood viscosity in a healthy person is estimated 2.7 times higher than the normal value while blood viscosity in person with the underlying metabolic syndrome is estimated 2.99 times higher than the normal value. Based on this preliminary report, a more increased blood viscosity level is detected in vaccine recipients with the underlying metabolic syndrome. Monitoring of the blood viscosity problem among a vaccine recipient who has metabolic syndrome is recommended.