As this issue coincides with World Immunization Week 2026 (the last week of April) [1], it is both timely and contextually relevant to reflect on vaccination through the lens of the Republic of Korea’s public health experience. The nationwide measles outbreak in 2000–2001 was brought under control through a government-led catch-up campaign, the institutionalization of a 2-dose vaccination schedule, and strengthened school-entry verification, all supported by universal health coverage that ensured equitable access. These combined efforts enabled the Republic of Korea to interrupt endemic transmission and subsequently sustain elimination status through high vaccination coverage, sensitive surveillance, and rapid outbreak response. At a time when several countries have experienced measles resurgence and even lost elimination status, the Republic of Korea’s experience underscores that elimination is not a 1-time achievement, but a system-level outcome that must be continuously maintained. In this context, World Immunization Week is not merely commemorative, but a reminder that vaccination is a system-level achievement requiring sustained policy commitment, equitable delivery, and continuous health system performance. This commitment is also reflected in the Republic of Korea through commemorative initiatives, including an immunization award and ceremony organized in collaboration with the International Vaccine Institute and its partners to recognize contributions to advancing vaccination as a global public good [2]. Marking the 50th anniversary of the Expanded Programme on Immunization, which is estimated to have prevented more than 154 million deaths globally since 1974 [3], this moment calls for renewed commitment to sustaining and strengthening immunization systems worldwide.

Moving from determinants to disease outcomes, several studies in this issue address infectious disease severity and transmission dynamics in clinical settings. A retrospective study from Vietnam identified cardiometabolic comorbidities, particularly hyperlipidemia and combinations of hypertension and cardiovascular disease, as significant predictors of severe dengue. This finding underscores the growing intersection between noncommunicable diseases and infectious disease outcomes and highlights the need for integrated risk stratification at the point of care. Similarly, a prospective cohort study among hemodialysis patients in India reported notable rates of hepatitis B and C seroconversion, with risk factors including multiple facility visits and dialyzer reuse. These findings point to persistent vulnerabilities in infection prevention and control practices among high-risk clinical populations.

At the population level, two studies highlight the importance of early-life and lifestyle determinants in shaping long-term health outcomes. A systematic review and meta-analysis on perinatal factors demonstrates that maternal conditions—including pre-pregnancy obesity, excessive gestational weight gain, cesarean delivery, and early-life exposures—significantly increase the risk of childhood obesity, while breastfeeding offers a protective effect. These findings reinforce the concept that prevention must begin before birth, aligning with a life-course approach to noncommunicable disease control. Complementing this, a cross-sectional study on dietary fat intake and sleep quality reveals complex associations between both the quantity and type of fat consumed and multiple dimensions of sleep. Together, these studies highlight that health systems must extend beyond clinical services to address upstream determinants that shape population health trajectories. Moving from determinants to disease outcomes, several studies in this issue address infectious disease severity and transmission dynamics in clinical settings. A retrospective study from Vietnam identified cardiometabolic comorbidities, particularly hyperlipidemia and combinations of hypertension and cardiovascular disease, as significant predictors of severe dengue. This finding underscores the growing intersection between noncommunicable diseases and infectious disease outcomes and highlights the need for integrated risk stratification at the point of care. Similarly, a prospective cohort study among hemodialysis patients in India reported notable rates of hepatitis B and C seroconversion, with risk factors including multiple facility visits and dialyzer reuse. These findings point to persistent vulnerabilities in infection prevention and control practices among high-risk clinical populations.

A study conducted in the Republic of Korea further provides molecular and epidemiological evidence of nosocomial transmission of severe fever with thrombocytopenia syndrome, with secondary infections occurring during high-risk procedures such as cardiopulmonary resuscitation in the absence of adequate personal protective equipment. This finding highlights the continuing importance of infection prevention and control as a core health system function, particularly in the context of emerging pathogens.

Beyond individual patient outcomes, this issue also addresses health system performance, particularly with respect to continuity of care. An analysis of tuberculosis surveillance data from Indonesia revealed that nearly 1 in 5 patients with drug-sensitive tuberculosis were lost to follow-up. The study identified multiple contributing factors, including non-standard treatment, human immunodeficiency virus co-infection, and gaps in referral systems. These findings illustrate systemic weaknesses in care delivery and emphasize the need for patient-centered interventions, stronger coordination, and robust monitoring systems to improve treatment adherence and outcomes.

Looking ahead, 2 articles explore the transformative potential of digital technologies in health care. A comprehensive review of artificial intelligence applications highlights its expanding role in diagnostics, predictive analytics, precision medicine, and health system efficiency, while also identifying persistent challenges related to data integration, algorithmic bias, and ethical governance. In parallel, a perspective on virtual reality outlines its potential to enhance medical education and patient engagement through immersive, interactive environments. These innovations signal a shift toward more adaptive, technology-enabled health systems while underscoring the importance of equitable access and responsible implementation.

In summary, this issue reflects the evolving public health landscape, in which traditional boundaries between communicable and noncommunicable diseases, prevention and care, and human and technological systems are increasingly blurred. Collectively, the studies call for a more integrated framework that combines life-course prevention, risk stratification, resilient health systems, and responsible innovation. As illustrated by the experience of immunization and measles elimination, achieving and sustaining population health gains ultimately depends on the continuous performance of health systems grounded in equity, evidence, and global cooperation.

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