Coronavirus disease 2019 (COVID-19) has rapidly spread worldwide since the first case of infection was confirmed in the Wuhan province of China in December 2019. To combat the unexpected global pandemic of COVID-19, many clinical trials of drug repositioning and novel antiviral drugs to develop effective treatments, as well as vaccine development to prevent infection, have been rapidly conducted worldwide. While drug development tends to take >10 years, mRNA vaccine, a new modality, was developed with incredible speed and was able to be used clinically within just one year of the COVID-19 outbreak, saving many lives and returning social activities to normal. The World Health Organization declared the end of the pandemic on May 5, 2023, and in Japan, the disease was reclassified from "class 2 equivalent" to "class 5" under the Infectious Diseases Control Law on May 8, 2023. While pharmaceutical and vaccine development was progressing vigorously around the world, Japan is clearly lagging behind, leading various issues to be raised. To prepare for the next pandemic, measures are currently being taken in Japan. This review summarizes the current state of drug discovery and treatment, focusing on the COVID-19 treatments and vaccines approved in Japan to date, as well as the ongoing countermeasures expected to resolve issues brought by the next pandemic.

The coronavirus disease 2019 (COVID-19) pandemic forced an unprecedented transformation in medical education, prompting our university to implement diverse measures to ensure both educational continuity and quality assurance. This study documents these efforts and the insights gained, while considering future directions. In the early stages of the pandemic, the university suspended all in-person classes. We swiftly began full-scale operation of our Learning Management System (LMS) (Webclass) and commenced recording and distributing lecture videos. The introduction of on-demand classes enabled flexible learning that could be tailored to the individual pace of each student, suggesting the need to transition towards Competency-Based Medical Education (CBME) and time-flexible education. The special provisions of Article 35 of the Copyright Act and the waiver of compensation fees legalized the online distribution of educational materials, expanding the scope of educational resource utilization. The library strengthened its provision of e-books and electronic journals, and by establishing off-campus access and non-visit-based services, it promoted self-directed learning using evidence-based medicine (EBM) tools and clinical procedure videos. In skills education, when clinical placements were temporarily suspended, alternative training using skills labs was implemented, and continuing education focused on infection control and personal protective equipment (PPE) donning/doffing drills. For Objective Structured Clinical Examination (OSCE) and simulated patient education, ventilation, disinfection, and mask wearing were strictly enforced, and simulators were used as needed. Clinical placements resumed gradually, but challenges remain in enhancing patient participation-based education. Moving forward, a hybrid model combining actual clinical practice with simulation education is essential. To address the changes in learning attitudes and reduced communication highlighted by the pandemic, enhanced flipped classrooms and collaborative learning are required. Overall, our university's experience demonstrates the need for sustainable reforms centered on flexibility, digitalization, safety, and competency-based education. Medical education must leverage the insights gained from crisis response to build resilient educational systems.

Streptococcus pneumoniae (S. pneumoniae) is a Gram-positive diplococcus commonly responsible for causing otitis media and non-bacteremic pneumonia in children. When this bacterium enters the circulation, it can induce various invasive pneumococcal diseases (IPDs), such as meningitis and bacteremic pneumonia. Given its ability to produce autolysin, an enzyme responsible for self-lysis, S. pneumoniae may undergo autolysis, which can hinder its identification via blood cultures. We herein report two pediatric cases diagnosed to have IPD despite prior pneumococcal vaccination but in whom the causative organism could not be identified through blood culture. Despite being a useful diagnostic tool in adults, urinary pneumococcal antigen testing has limited utility in children due to the high rates of nasopharyngeal carriage, which can cause false positive results. Although the introduction of pneumococcal conjugate vaccines (PCVs) has significantly reduced infections caused by vaccine-covered serotypes, the emergence of non-vaccine serotypes due to serotype replacement has been concerning. The recently introduced 15- and 20-valent PCVs (PCV15 and PCV20) are expected to further enhance protection against IPD. Despite these advances, the increase in IPDs caused by non-vaccine serotypes remains problematic. Therefore, effective infection control requires a multifaceted approach, including vaccine development, appropriate use of antimicrobial agents, and enhanced surveillance.