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.