A new study that examined health data on 18 million people reveals a higher incidence of mental illnesses for up to a year following severe COVID-19 in unvaccinated people. Vaccination appeared to mitigate the adverse effects of COVID-19 on mental illnesses. The University of Bristol-led study, published in JAMA Psychiatry on August 21st, 2024, investigated associations of COVID-19 with mental illnesses according to time since diagnosis and vaccination status.