Cases of laboratory-confirmed SARS-CoV-2 reinfection have been reported in a number of countries. Further, the level of natural immunity induced by SARS-CoV-2 infection is not fully clear, nor is it clear if a primary infection is protective against reinfection. To investigate the potential association between serum antibody titres and reinfection of SARS-CoV-2, ferrets with different levels of NAb titres after primary SARS-CoV-2 infection were subjected to reinfection with a heterologous SARS-CoV-2 strain. All heterologous SARS-CoV-2 reinfected ferrets showed active virus replication in the upper respiratory and gastro-intestinal tracts. However, the high NAb titre group showed attenuated viral replication and rapid viral clearance. In addition, direct-contact transmission was observed only from reinfected ferrets with low NAb titres (<20), and not from other groups. Further, lung histopathology demonstrated the presence of limited inflammatory regions in the high NAb titre groups compared with control and low NAb groups. This study demonstrates a close correlation between a low NAb titre and SARS-CoV-2 reinfection in a recovered ferret reinfection model.

In this study, we investigated the proportion of transmitted drug resistance (TDR) mutations and human immunodeficiency virus (HIV)-1 subtypes among 487 antiretroviral therapy (ART)-naïve individuals in South Korea from 2021 to 2024 to inform more effective treatment strategies. Consistent with previous reports, subtype B was most prevalent among HIV-1 subtypes at 50.7%; however, its proportion decreased annually (p = 0.047). Various subtypes of circulating recombinant forms (CRFs) were analyzed in this study, resulting in high genetic diversity. The subtype distributions of Korean and non-Korean patients differed, with subtype B (53.7%) and CRF01_AE (34.4%) being dominant in the former and latter, respectively. TDR across antiretroviral drug classes was approximately 3.5% in South Korea. Non-nucleoside reverse transcriptase inhibitors elicited the greatest drug resistance, which increased from 2021 to 2023, with a slight decrease in 2024. The integrase strand transfer inhibitor drugs, elvitegravir and raltegravir, most frequently exhibited high resistance scores. We provide a comprehensive overview of the HIV-1 genetic distribution and TDR patterns in South Korea from 2021 to 2024. Within the broader context of HIV-1 epidemiology in Asia and the Pacific, the findings contribute to a comprehensive understanding of the global distribution of HIV-1 resistance and genotypes, enabling the development of effective interventions.

김가영, 왕진숙, 김희만, 김설희, 김은지, 한명국*. Public Health Weekly Report 2024;17:1863-73. https://doi.org/10.56786/PHWR.2024.17.44.1

견미랑, 김은지, 라부미, 이예지, 조승례, 박선환, 박은서, 이덕용, 주혁. Public Health Weekly Report 2026;19:1052-68. https://doi.org/10.56786/PHWR.2026.19.26.2

This study investigated the proportion and trend of transmitted drug resistance (TDR) mutations and human immunodeficiency virus (HIV)-1 subtypes among 487 antiretroviral therapy–naive individuals in Korea from 2021 to 2024 to inform better treatment strategies. Consistent with previous reports, subtype B was the most prevalent among HIV-1 subtypes at 50.7%; however, its proportion has decreased annually. The distribution of circulating recombinant forms has increased, leading to a high genetic diversity. The subtype distributions of Korean and non-Korean patients differed, with subtype B (53.7%) and CRF01_AE (34.4%) being dominant in the former and latter, respectively. TDR across antiretroviral drug classes was approximately 3.5% in Korea. Non-nucleoside reverse transcriptase inhibitors elicited the highest level of drug resistance, which increased from 2021 to 2023, with a slight decrease in 2024. The integrase strand transfer inhibitor drugs, elvitegravir and raltegravir, most frequently exhibited high resistance scores. We provide a comprehensive overview of the HIV genetic distribution and TDR trends in Korea from 2021 to 2024. Within the broader context of HIV epidemiology in Asia and the Pacific, the findings contribute to a comprehensive understanding of the global distribution of HIV resistance and genotypes, enabling the development of effective interventions.