Early Mortality After the First Dose of COVID-19 Vaccination: A Target Trial Emulation.

Background: Vaccine hesitancy persists alongside concerns about the safety of coronavirus disease 2019 (COVID-19) vaccines. We aimed to examine the effect of COVID-19 vaccination on risk of death among US veterans.

Methods: We conducted a target trial emulation to estimate and compare risk of death up to 60 days under two COVID-19 vaccination strategies: vaccination within 7 days of enrollment versus no vaccination through follow-up.

Incidence Rates and Clinical Characteristics of Patients With Confirmed Myocarditis or Pericarditis Following COVID-19 mRNA Vaccination: Experience of the Veterans Health Administration Through 9 October 2022.

Background: Although the benefits outweigh the risks, COVID-19 vaccines have been associated with an increased risk of myocarditis and pericarditis. This report is based on a national US veteran population with confirmed myocarditis/pericarditis following mRNA COVID-19 vaccines according to the near real-time active surveillance program of Veterans Affairs.

Methods: This study is based on a cohort evaluation of all adults administered ≥1 mRNA COVID-19 vaccine, including boosters, in the Veterans Health Administration between 14 December 2020 and 9 October 2022.