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/m2. 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. METHODS: We retrospectively investigated all patients hospitalized for COVID-19 in Osaka City Juso Hospital between March 1, 2021, and June 30, 2022. Using multivariable logistic analysis, we calculated the adjusted odds ratios (aORs) for severe disease after vaccination in the whole dataset and in subsets stratified by age, sex, BMI, smoking history, pre-hospitalization location, and comorbidities. RESULTS: The analysis included 1041 patients. Multivariable logistic analysis showed that vaccination was associated with a low risk of severe disease, with an aOR of 0.21 (95% confidence interval: 0.12-0.36, p < 0.001). On stratifying the analysis according to background characteristics, lower aORs for severe COVID-19 were found for patients aged ≥60 years and for those with diabetes or hypertension. Notably, patients with BMI >30 kg/m2 and those with BMI ≥18 kg/m2 and ≤30 kg/m2 benefited from vaccination. CONCLUSIONS: Individuals with diabetes or hypertension and those of age ≥60 years benefited more from vaccination than did their counterparts. We recommend extending the fourth round of vaccinations to individuals with a BMI of 18-30 kg/m2.

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. Responses were obtained from 285 out of 1,150 patients. More than half of the participants reported Long COVID symptoms of varying severity 1 year after COVID-19. Common sequelae included fatigue, dyspnea, alopecia, concentration problems, memory problems, sleeplessness, and joint pain, which often significantly reduced their QOL. COVID-19 severity was strongly associated with sputum production, chest pain, dyspnea, sore throat, and diarrhea, but not with fatigue, dysgeusia, anosmia, alopecia, and sleeplessness. Fatigue, dysgeusia, anosmia, alopecia, and sleeplessness affected the QOL among participants with asymptomatic or mild COVID-19 during the acute phase. Moreover, these sequelae persisted for prolonged periods.