COVID-19 vaccination benefits in preventing severe disease in mild-to-moderate cases: An analysis in the first specialized hospital for COVID-19 in Japan.

Background: In Japan, the fourth round of coronavirus disease (COVID-19) vaccination is ongoing and is targeted at medical staff and nursing home workers, individuals aged ≥60 years, and those with comorbidities or other high-risk factors, including body mass index (BMI) ≥30 kg/m. The incidence of severe COVID-19 decreased markedly after widespread COVID-19 vaccination drives, and our hospital experienced a similar trend. We, therefore, examined the characteristics of our patients to clarify who benefited the most from vaccination.

A cross-sectional, multicenter survey of the prevalence and risk factors for Long COVID.

Long-term sequelae of the coronavirus disease (COVID-19) constitute Long COVID. Although Long COVID has been reported globally, its risk factors and effects on quality of life (QOL) remain unclear. We conducted a cross-sectional study using questionnaires and electronic medical records of COVID-19 patients who were diagnosed or hospitalized at five facilities in Japan.