Assessing the determinants of influenza and COVID-19 vaccine co-administration decisions in the elderly.

This research examines the low rate of co-administration of influenza and COVID-19 vaccines among seniors aged 65 and older in Korea, despite recommendations from authorities and academia worldwide. The study aimed to understand the influence of general characteristics and health beliefs on the vaccination choices of seniors, who were categorized into four groups based on their vaccination status: influenza only, COVID-19 only, both, or neither. A total of 400 participants, aged 65 and above, were selected through proportional stratified random sampling from five major Korean regions for a survey conducted between November 24th and December 15th, 2023. The results indicated no significant differences in general characteristics across these groups. However, regarding the health beliefs showed significant differences in perceived susceptibility and self-efficacy between the influenza-only and co-administration groups. Higher levels of perceived susceptibility and self-efficacy were associated with choosing co-administration. Contrary to previous studies focusing on safety concerns as a primary factor in vaccine hesitancy, this study highlights the role of individual health-related beliefs, particularly perceived susceptibility and self-efficacy, as critical in influencing the decision for co-administration among the elderly in Korea.

Twenty Years of Progress and the Way Forward: Immunization Registry Information System in Korea.

The National Immunization Program in The Republic of Korea offers mandatory and free vaccinations to children under 12, regulated by the Infectious Disease Prevention and Control Act. Tracking vaccination coverage is crucial for population protection and public health strategies. Since 2002, the Immunization Registry Information System (IRIS) has been used nationwide to capture vaccination data. This study reviewed documents related to IRIS's establishment and development. The Republic of Korea legally supports IRIS's construction and data collection, integrating vaccination data with the Ministry of the Interior and Safety's resident registration to minimize errors. This collaboration also facilitates cost reimbursement and digital registration, promoting wider vaccination coverage. IRIS manages expense claims once vaccination details are logged, and authorized medical institutions can access these records in real-time. Since 2015, the Korea Disease Control and Prevention Agency has been compiling annual data on national vaccination coverage. IRIS also sends automated reminders in 12 languages, reports adverse effects, and issues vaccination certificates. However, IRIS lacks integration between vaccine and disease registries, unlike countries such as England, Denmark, and the Netherlands. Improving integration capabilities could enhance IRIS's support for public health through an integrated information system.

Effect of the human papillomavirus vaccine on the risk of genital warts: a nationwide cohort study of South Korean adolescent girls.

Objectives: The purpose of this study was to assess the effectiveness of human papillomavirus (HPV) vaccination administered to adolescent girls through South Korea's National Immunization Program. Methods: This retrospective cohort study included individuals who were 12 to 13 years old, whether vaccinated or unvaccinated, between July 2016 and December 2017. The incidence of genital warts (GWs) was monitored through 2021. Time-stratified hazard ratios (HRs) were estimated, adjusting for birth year, socioeconomic status, and the level of urbanization of the region, and were presented with 95% confidence intervals (CIs). Data were sourced from the Immunization Registry Integration System, linked with the National Health Information Database. Results: The study included 332,062 adolescent girls, with an average follow-up period of approximately 4.6 years. Except for the first year, the HRs for the vaccinated group were lower than those for the unvaccinated group. The HRs for specific cutoff years were as follows: year 2, 0.62 (95% CI, 0.31 to 1.13); year 3, 0.58 (95% CI, 0.35 to 0.96); and year 4 and beyond, 0.39 (95% CI, 0.28 to 0.52). Conclusion: Our findings indicate that HPV vaccination was associated with a reduction in the risk of GWs among adolescent girls. Notably, this reduction became significant as the incidence of GWs increased with age.

JYNNEOS vaccine safety monitoring in the Republic of Korea, 2022: a cross-sectional study.

BACKGROUND: With the recent global mpox outbreak, the JYNNEOS vaccine (Modified Vaccinia Ankara-Bavarian Nordic) was developed as a third-generation smallpox vaccine and initially favored for mpox immunization. Vaccine-associated side effects contribute to vaccine hesitancy. Consequently, tracking adverse events post-immunization is crucial for safety management. This study used data from the national active vaccine safety surveillance conducted in Korea from August 25 to November 24, 2022 to detect potential safety signals and adverse events. METHODS: Data on health conditions following vaccination were gathered from web-based surveys and reported via active surveillance through the Immunization Registry Information System. This follow-up system functioned via a text message link, surveying adverse events and health conditions beginning on the second day post-vaccination. Information about specific adverse events, including both local and systemic reactions, was collected. RESULTS: The study included 86 healthcare workers who had received at least 1 dose of the JYNNEOS vaccine. Among the respondents, 79.1% reported experiencing at least 1 adverse event, with the majority being local reactions at the injection site. The incidence of adverse events was higher following the first dose (67.9%) than after the second dose (34.4%). The most frequently reported adverse event for both doses was mild pain at the injection site. CONCLUSION: The study provides crucial information on the safety of the JYNNEOS vaccine, demonstrating that most adverse events were manageable and predominantly localized to the injection site. Nonetheless, additional research is needed on the safety of various vaccine administration techniques and the vaccine's effects on broader demographics.

Why school is crucial to increase vaccination coverage for children: Evaluation of school vaccination check program in South Korea 2021-2022.

The School Vaccination Check Program (SVCP) is a public health measure that aims to achieve high levels of National Immunization Program (NIP) vaccination coverage for children by checking the completion of the vaccination schedule for students when they enter elementary or middle school. Due to the COVID-19 pandemic, the SVCP was stopped in 2020 and 2021, and restarted in June-August 2022. In this study, we examined and quantified the relationship with SVCP and the vaccination uptake by comparing the vaccination coverage of 2021 and 2022. Based on the standard schedule, the vaccination records of DTaP5, IPV4, MMR2 and IJEV4 were evaluated for elementary school students. The Tdap6, IJEV5 and HPV1 were evaluated for the students from middle school. Using a difference-in-difference study design and national level big data, the study compared vaccination coverage as of August 2021 and 2022. The study found that the SVCP was effective in increasing vaccination coverage for targeted vaccinations such as DTaP5, IPV4, MMR2 and IJEV4 for elementary school students, and Tdap6, IJEV5 for middle school students. However, the SVCP did not show a statistically significant effect on increasing vaccination coverage on HPV1 for middle school students. School can play an important role to improve vaccination coverage. Therefore, close collaboration with health and education authority is crucial to accomplish successful vaccination program reducing vaccine preventable disease outbreaks in schools.

Monkeypox Vaccination in the Republic of Korea: Identifying the High-Risk Target Group.

In June 2022, the first monkeypox case was reported as imported into Korea. The general public asked whether they should get vaccinated against monkeypox because of the recent COVID-19 vaccination experience. As of the current monkeypox outbreak situation, a ring vaccination strategy for the high-risk group is more appropriate than the mass population vaccination with smallpox vaccines. Therefore, identifying the proper target group by available vaccines based on the risk and benefit analysis is a key issue of the vaccination program. In addition, the target group should be reviewed by the epidemiological situation of the jurisdiction along with the updated evidence of the monkeypox virus on transmission dynamics, severity, and fatality.

COVID-19 vaccination program in South Korea: A long journey toward a new normal.

Objectives: This article presents an overview of South Korea's COVID-19 vaccination program and describes the key measures the country enacted to overcome the initial vaccine shortage and expand the vaccinated population. Methods: Review of official government documents, international and local databases, and media reports regarding the COVID-19 vaccination program. Results: South Korea overcame the early phase of vaccine shortage and quickly expanded vaccination coverage by evidence-based priority setting and transparent information sharing using innovative technologies. Conclusions: It was important to secure effective and safe vaccines as early as possible to fight against COVID-19, yet the delayed start did not equate to failure. Persistent innovation and rapid adaptation to changing circumstances allowed South Korea to expand its vaccination coverage despite the initial delay in procuring vaccine doses. However, the emergence of virus variants and the waning effect of the vaccines require that Korea initiate a new vaccination program that includes booster shots. Public Interest Summary: Vaccination is a safe and effective way to fight against COVID-19. However, acquiring adequate vaccine supply and administering doses safely and effectively are difficult tasks. South Korea accomplished this mission initially using innovative technologies and rapidly adapting to changing circumstances. However, new variants and decreasing vaccine efficacy induce the Korean government to begin another vaccination program that includes booster shots.