COVID-19 vaccine effectiveness against severe COVID-19 requiring oxygen therapy, invasive mechanical ventilation, and death in Japan: A multicenter case-control study (MOTIVATE study).

INTRODUCTION: Since the SARS-CoV-2 Omicron variant became dominant, assessing COVID-19 vaccine effectiveness (VE) against severe disease using hospitalization as an outcome became more challenging due to incidental infections via admission screening and variable admission criteria, resulting in a wide range of estimates. To address this, the World Health Organization (WHO) guidance recommends the use of outcomes that are more specific to severe pneumonia such as oxygen use and mechanical ventilation. METHODS: A case-control study was conducted in 24 hospitals in Japan for the Delta-dominant period (August-November 2021; "Delta") and early Omicron (BA.1/BA.2)-dominant period (January-June 2022; "Omicron"). Detailed chart review/interviews were conducted in January-May 2023. VE was measured using various outcomes including disease requiring oxygen therapy, disease requiring invasive mechanical ventilation (IMV), death, outcome restricting to "true" severe COVID-19 (where oxygen requirement is due to COVID-19 rather than another condition(s)), and progression from oxygen use to IMV or death among COVID-19 patients. RESULTS: The analysis included 2125 individuals with respiratory failure (1608 cases [75.7%]; 99.2% of vaccinees received mRNA vaccines). During Delta, 2 doses provided high protection for up to 6 months (oxygen requirement: 95.2% [95% CI:88.7-98.0%] [restricted to "true" severe COVID-19: 95.5% {89.3-98.1%}]; IMV: 99.6% [97.3-99.9%]; fatal: 98.6% [92.3-99.7%]). During Omicron, 3 doses provided high protection for up to 6 months (oxygen requirement: 85.5% [68.8-93.3%] ["true" severe COVID-19: 88.1% {73.6-94.7%}]; IMV: 97.9% [85.9-99.7%]; fatal: 99.6% [95.2-99.97]). There was a trend towards higher VE for more severe and specific outcomes. CONCLUSION: Multiple outcomes pointed towards high protection of 2 doses during Delta and 3 doses during Omicron. These results demonstrate the importance of using severe and specific outcomes to accurately measure VE against severe COVID-19, as recommended in WHO guidance in settings of intense transmission as seen during Omicron.

Intralymphatic histiocytosis in a patient with lung adenocarcinoma treated with pembrolizumab: a case report.

BACKGROUND: Pembrolizumab, an anti-programmed cell death-1 protein monoclonal antibody, is effective for patients with advanced non-small-cell lung cancer. However, immune checkpoint inhibitors such as pembrolizumab induce various immune-related adverse events, involving the lung, liver, gastrointestinal, endocrine system, and skin. Intralymphatic histiocytosis (ILH) is a rare, chronic cutaneous disorder with a reactive inflammatory component, which often occurs in patients with rheumatoid arthritis. CASE PRESENTATION: We present a 67-year-old man with lung adenocarcinoma who developed ILH associated with pembrolizumab treatment. He was treated with palliative thoracic radiotherapy for superior vena cava syndrome. Subsequently, he received four cycles of pembrolizumab. Approximately 2.5 months after the initiation of pembrolizumab, he developed erythema on the trunk of his body. Based on findings of skin biopsies, he was diagnosed with pembrolizumab-induced ILH. Moreover, the upregulation of tumor necrosis factor-α was observed during pembrolizumab therapy. CONCLUSIONS: This is the first report of ILH induced by pembrolizumab in a patient with lung adenocarcinoma.