BACKGROUND: Many previous studies have reported COVID-19 vaccine effectiveness, but there are few studies in Japan. This community-based, retrospective observational study investigated the association between vaccination status and COVID-19-related health outcomes in COVID-19 patients by SARS-CoV-2 variant type. METHODS: The study participants were 24,314 COVID-19 patients aged 12 or older whose diagnoses were reported to the Nara Prefecture Chuwa Public Health Center from April 2021 to March 2022, during periods when the alpha, delta, and omicron variants of COVID-19 were predominant. The outcome variables were severe health consequences (SHC) (i.e., ICU admission and COVID-19-related death), hospitalization, and extension of recovery period. The explanatory variable was vaccination status at least 14 days prior to infection. Covariates included gender, age, population size, the number of risk factors for aggravation, and the number of symptoms at diagnosis. The generalized estimating equations of the multivariable Poisson regression models were used to estimate the adjusted incidence proportion (AIP) and 95% confidence interval (CI) for each health outcome. We performed stratified analyses by SARS-CoV-2 variant type, but the association between vaccination status and COVID-19-related health outcomes was stratified only for the delta and omicron variants due to the small number of vaccinated patients during the alpha variant. RESULTS: Of the 24,314 participants, 255 (1.0%) had SHC; of the 24,059 participants without SHC, 2,102 (8.7%) were hospitalized; and of the 19,603 participants without SHC, hospitalization, and missing data on recovery period, 2,960 (15.1%) had extension of recovery period. Multivariable Poisson regression models showed that regardless of SARS-CoV-2 variant type or health outcome, those who received two or more vaccine doses had significantly lower risk of health outcomes than those who did not receive the vaccine, and there was a dose-response relationship in which the AIP for health outcomes decreased with an increased number of vaccinations. CONCLUSION A higher number of vaccinations were associated with lower risk of COVID-19-related health outcomes, not only in the delta variant but also in the omicron variant. Our findings suggest that increasing the number of COVID-19 vaccine doses can prevent severe disease and lead to early recovery of patients not requiring hospitalization.
Humans ; COVID-19/prevention & control* ; SARS-CoV-2 ; COVID-19 Vaccines ; Japan/epidemiology* ; Independent Living ; Outcome Assessment, Health Care

In some molecular targeted therapies, skin disorders including acne-like rashes or maculopapular rashes frequently appear, which are often clinically problematic. In Kampo medicine, it has been reported that the combination of jumihaidokuto and orengedokuto (hereinafter called JHT + OGT) is effective for acne. In this study, we report the experiences of JHT + OGT for the treatment of rashes caused by molecular targeted therapies. We extracted patients from June 2013 to June 2017 who took molecular targeted therapies and the treatment with JHT + OGT for skin rashes. The primary endpoint was severity of rashes before and after treatment by JHT + OGT (judged by CTCAE v4.0). In 22 patients (14 males and 8 females), the rashes after treatment with JHT + OGT significantly improved compared with those before treatment (from the median grade of 2 to 1 [p = 0.011]), with 14 cases of improvement, 6 cases of no change, and 2 cases of deterioration. It was suggested that JHT + OGT for skin rashes caused by molecular targeted therapies could be one of the treatment options.