The coronavirus disease 2019 (COVID-19) continues to threaten public health in Korea although several surges have passed in the past 3 years since 2019. Although patients with mild-to-moderate COVID-19 can usually recover at home, antiviral therapy to prevent disease progression and hospitalization is beneficial for those at high risk of progressing to severe COVID-19. The purpose of this article was to review how antivirals have been rolled out for the treatment of COVID-19 and how domestic and international guidelines for their use have evolved. Several evidence-based treatment guidelines have been developed in Korea, including those derived from domestic studies. Although many different antiviral agents were nominated as promising therapeutics at the onset of the pandemic, most failed to show efficacy in clinical trials. Currently, three types of antiviral agents—nirmatrelvir-ritonavir, molnupiravir, and remdesivir—are available in Korea to treat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Each antiviral has its advantages and disadvantages. For most individuals, nirmatrelvir/ritonavir is preferred because of its high efficacy and convenience of administration. When serious drug interactions occur or are expected with nirmatrelvir/ritonavir administration, 3 days of remdesivir treatment is shown to be a reasonable alternative. Molnupiravir may be prescribed with caution only if no other therapeutic options are available or acceptable.

Background: Antiretroviral therapy (ART) has been shown to significantly reduce the likelihood of transmission to other people as well as promoting the health of people living with Human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) (PLH). The purpose of this study was to assess the HIV care continuum of PLH in Korea using the national health insurance system (NHIS) database. Materials and Methods: From 2006 to 2015, ART prescription/laboratory test claim data and enlisted accompanying comorbidities were extracted from the NHIS database. Utilizing these data, proportion of PLH on ART among those who registered to Korea Disease Control and Prevention Agency (KDCA), HIV viral load testing, prescription trends of ART, medication possession ratio (MPR) of ART, and accompanying comorbidities were reviewed. Factors related with MPR <90% was also investigated among demographic factors, ART prescription, and accompanying comorbidities. Results: During the observation period, the number of people receiving ART prescription increased from 2,076 in 2006 to 9,201 in 2015. Considering the number of PLHs reported by the KDCA, the proportion of PLHs who received ART prescription increased from 55.4% to 87.6% during the study period. The median value of ART MPR increased from 76.4% to 94.2% and the proportion of patients with MPR >90% increased from 54.3% to 78.2%. The most commonly accompanying comorbidities were dyslipidemia (55.7%), osteoporosis (16.3%), hypertension (15.7%) and diabetes (13.7%), respectively. The proportion of PLH with two or more comorbid conditions increased from 22.0% to 31.6%. Regarding the factors associated with suboptimal compliance, age less than 50 years old, under support of National Medical Aid, alcoholic liver disease, mental and behavioral disorders due to use of alcohol, and ART regimen of protease inhibitor and non-single table regimen integrase strand transfer inhibitor were related with MPR <90%. Conclusion The proportion of PLHs who received ART prescription and median MPR of ART increased during the study period. However, proportion of patients with MPR >90% was 78.2% in 2015 and there are still much room for improvement in the aspect of compliance.

Background: Antiretroviral therapy (ART) has been shown to significantly reduce the likelihood of transmission to other people as well as promoting the health of people living with Human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) (PLH). The purpose of this study was to assess the HIV care continuum of PLH in Korea using the national health insurance system (NHIS) database. Materials and Methods: From 2006 to 2015, ART prescription/laboratory test claim data and enlisted accompanying comorbidities were extracted from the NHIS database. Utilizing these data, proportion of PLH on ART among those who registered to Korea Disease Control and Prevention Agency (KDCA), HIV viral load testing, prescription trends of ART, medication possession ratio (MPR) of ART, and accompanying comorbidities were reviewed. Factors related with MPR <90% was also investigated among demographic factors, ART prescription, and accompanying comorbidities. Results: During the observation period, the number of people receiving ART prescription increased from 2,076 in 2006 to 9,201 in 2015. Considering the number of PLHs reported by the KDCA, the proportion of PLHs who received ART prescription increased from 55.4% to 87.6% during the study period. The median value of ART MPR increased from 76.4% to 94.2% and the proportion of patients with MPR >90% increased from 54.3% to 78.2%. The most commonly accompanying comorbidities were dyslipidemia (55.7%), osteoporosis (16.3%), hypertension (15.7%) and diabetes (13.7%), respectively. The proportion of PLH with two or more comorbid conditions increased from 22.0% to 31.6%. Regarding the factors associated with suboptimal compliance, age less than 50 years old, under support of National Medical Aid, alcoholic liver disease, mental and behavioral disorders due to use of alcohol, and ART regimen of protease inhibitor and non-single table regimen integrase strand transfer inhibitor were related with MPR <90%. Conclusion The proportion of PLHs who received ART prescription and median MPR of ART increased during the study period. However, proportion of patients with MPR >90% was 78.2% in 2015 and there are still much room for improvement in the aspect of compliance.

Although the global incidence of human immunodeficiency virus (HIV) has decreased significantly since modern antiretroviral therapy (ART), new HIV infections steadily occur, in the Republic of Korea. Based on the understanding of the risk factors for HIV infection, combined strategic behavioral and biomedical interventions should be implemented to reduce HIV infection. This paper reviews the strategies for the prevention of HIV infection.Current Concepts: While the consistent use of latex condoms is effective for the prevention of HIV transmission, consistent use of condoms is low among sexually active individuals. ART can be initiated, after exposure, to prevent HIV infection (post-exposure prophylaxis) after occupational or sexual exposure, injection drug use, and other nonoccupational exposures to HIV. There is a negligible risk of sexual transmission of HIV when the HIV-infected sexual partner has durably suppressed viral replication with ART. Antiretroviral agents have been shown to be highly effective when administered prophylactically to HIV-uninfected but at-risk individuals (preexposure prophylaxis). A high-risk group, such as men who have sex with men, is required to be included in health insurance care benefits for pre-exposure prophylaxis, in addition to the current partners of HIV-infected individuals, to ensure its efficacy.Discussion and Conclusion: HIV-related deaths are rapidly decreasing, but new HIV infections continue to occur. In an environment where a cure or the development of vaccines is unlikely, a multifaceted and proactive approach is required to minimize new HIV infections.

In response to the Mpox domestic epidemic, South Korea initiated a nationwide vaccination program in May 2023, administering a 0.1 mL intradermal dose of JYNNEOS (Modified Vaccinia Ankara vaccine, Bavarian Nordic) to a high-risk group. To investigate the adverse reactions after intradermal JYNNEOS vaccination, an anonymous online survey was conducted at the National Medical Center from May 22 to July 31, 2023. Overall, 142 individuals responded. Over 80% of the respondents reported local reactions of predominantly mild severity. The predominant local reactions were pruritus, redness, and swelling; their incidence rates after the first dose were 66.2%, 48.1%, and 49.4%, respectively; the corresponding rates after the second dose were 69.2%, 60.6%, and 53.8%. Fewer respondents reported systemic symptoms. The most common systemic symptom was fatigue, the incidence rates of which after the first and second doses were 37.7% and 24.6%, respectively. Overall, the intradermally administered JYNNEOS vaccine appeared well tolerated.

Background: There is growing evidence that abnormal liver function tests (LFTs) are common in patients with coronavirus disease 2019 (COVID-19). However, it is not known whether viral involvement in the liver differs according to the strain. We investigated the impact on liver injury in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta (B.1.617.2) variants. Materials and Methods: We conducted a single-center, retrospective cohort study, including 372 patients admitted during the pre-Delta period (PDP: between February 1 and November 30, 2020) and 137 patients admitted during the Delta period (DP: between August 1 and August 31, 2021). Initial liver injury was defined as alanine aminotransferase (ALT) or aspartate aminotransferase (AST) levels ≥3 × the upper limit of normal (ULN) or alkaline phosphatase (ALP) or total bilirubin ≥2 × the ULN within 3 days from admission. Results: Of 509 patients with COVID-19 included in our study, 38 (7.5%) patients had initial liver injury. The DP group had a significantly higher rate of initial liver injury than the PDP group (PDP: 5.9% vs. DP: 11.7%, P = 0.028). The DP group (adjusted odds ratio [aOR]: 2.737, 95% confidence interval [CI]: 1.322 – 5.666) was independently associated with initial liver injury. During hospitalization, 160 (31.4%) patients had severe COVID-19. The DP group and initial liver injury had higher odds of progressing to severe COVID-19 (aOR: 2.664, 95% CI: 1.526 - 4.648, and aOR: 4.409, 95% CI: 1.816 - 10.707, respectively). The mediation analysis suggested that initial liver injury mediates the relationship between SARS-CoV-2 Delta variant infection and severe COVID-19 (unstandardized beta coefficient = 0.980, Standard error = 0.284, P = 0.001). Conclusion Initial liver injury is more common in COVID-19 patients with Delta variants. Also, Delta variants and initial liver injury are associated with poor clinical outcomes.

Background: Because of the very low incidence of human immunodeficiency virus (HIV) coinfection in Korea, data on hepatitis C virus (HCV)/HIV coinfection are limited. This study aimed to investigate the clinical characteristics and treatment outcomes of patients with HCV/HIV coinfection in Korea. Methods: We performed a retrospective cohort study of all HCV-monoinfected and HCV/ HIV-coinfected patients treated with antivirals at National Medical Center in Seoul, Korea, between January 2009 and March 2020. Results: We enrolled 220 HCV-monoinfected and 23 HCV/HIV-coinfected patients treated with antivirals. The HCV/HIV-coinfected patients were younger (HCV vs. HCV/HIV: 57.3 ± 11.3 vs. 40.7 ± 10.1 years, P < 0.001) and had a higher proportion of men (HCV vs. HCV/ HIV: 54.5% [n = 120] vs. 91.3% [n = 21], P < 0.001) than the HCV-monoinfected patients.Genotype 1b and 2 were most common in both HCV monoinfection and HCV/HIV coinfection groups. HCV-monoinfected patients had a higher incidence of genotype 1b and 2 than HCV/HIV-coinfected patients (HCV vs. HCV/HIV: 95.4% [n = 210] vs. 73.9% [n = 17], P < 0.001), while the HCV/HIV-coinfected patients had genotype 1a (HCV vs. HCV/HIV: 1.8% [n = 4] vs. 21.7% [n = 5], P < 0.001). The fibrosis-4 index was significantly lower in the HCV/ HIV-coinfected patients than in the HCV-monoinfected patients (HCV vs. HCV/HIV: 3.81 ± 3.38 vs. 1.66 ± 1.10, P < 0.001). Among the direct-acting antivirals (DAA)-treated patients, the sustained viral response (SVR) rate did not differ significantly between both groups (HCV vs.HCV/HIV: 94.9% [93/99] vs. 90.9% [10/11], P = 0.480). Conclusion In Korea, the HCV/HIV-coinfected patients who received antiviral treatment were younger, had higher proportion of men and incidence of genotype 1a, and had less advanced fibrosis than the HCV-monoinfected patients. In actual clinical settings, HCV/HIV-coinfected patients show excellent SVR to DAA treatment, similar to HCVmonoinfected patients.

Background: Coinfection with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) can cause more rapid progression to cirrhosis than HCV-monoinfection. In this study, incident HCV case (IHCV)s were investigated in a HIV clinic in Korea. Materials and Methods: A retrospective HIV cohort was constructed who visited National Medical Center in Korea from 2013 to 2022 and performed ≥ 1 anti-HCV antibody tests (anti-HCV) during the study period. IHCV was defined as newly confirmed HCV infection by PCR with a prior negative anti-HCV and factors associated with IHCV were investigated among alanine aminotransferase (ALT) >150 IU/mL sub-cohort without plausible reasons for ALT elevation. Results: Overall, 2,567 HIV clinic visitors were recruited during the study period and 42 (1.63%) were confirmed as HIV/HCV co-infection. Fifteen IHCVs were identified during the study period. While no IHCV was observed in 2013–2015, incidence of 2016–2019 and 2020–2022 were 0.84 and 1.48 per 1000 person-year, respectively. Subtype 1a were more common among IHCVs in 2020–2022 (8/9) while subtype 2 dominated in 2016–2019 (5/6, P=0.003). Most IHCVs were identified during the evaluation of de novo liver enzyme elevation which was identified through the regularly performed blood tests (86.7%, 13/15). Comparing twelve IHCVs with ALT>150 IU/mL with 58 HIV mono-infection comparators whose peak ALT exceeded 150 IU/mL during the study period, age, sex, HIV/HCV infection risk factor, CD4 cell count, and HIV-RNA viral load were not different between two groups. However, mean peak ALT of IHCVs was higher than comparators (776 vs. 237, P<0.001) and syphilis treatment within prior 24 months of ALT elevation was more common in IHCV group (41.7% vs. 12.7%, P=0.026). Conclusion Incidence rate of HCV among PLH revealed increasing trend between 2013 and 2022 among visitors at a HIV clinic in Korea. Subtype 1a dominated among IHCVs after 2020 and recent syphilis treatment was associated with IHCVs.

Background: Coinfection with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) can cause more rapid progression to cirrhosis than HCV-monoinfection. In this study, incident HCV case (IHCV)s were investigated in a HIV clinic in Korea. Materials and Methods: A retrospective HIV cohort was constructed who visited National Medical Center in Korea from 2013 to 2022 and performed ≥ 1 anti-HCV antibody tests (anti-HCV) during the study period. IHCV was defined as newly confirmed HCV infection by PCR with a prior negative anti-HCV and factors associated with IHCV were investigated among alanine aminotransferase (ALT) >150 IU/mL sub-cohort without plausible reasons for ALT elevation. Results: Overall, 2,567 HIV clinic visitors were recruited during the study period and 42 (1.63%) were confirmed as HIV/HCV co-infection. Fifteen IHCVs were identified during the study period. While no IHCV was observed in 2013–2015, incidence of 2016–2019 and 2020–2022 were 0.84 and 1.48 per 1000 person-year, respectively. Subtype 1a were more common among IHCVs in 2020–2022 (8/9) while subtype 2 dominated in 2016–2019 (5/6, P=0.003). Most IHCVs were identified during the evaluation of de novo liver enzyme elevation which was identified through the regularly performed blood tests (86.7%, 13/15). Comparing twelve IHCVs with ALT>150 IU/mL with 58 HIV mono-infection comparators whose peak ALT exceeded 150 IU/mL during the study period, age, sex, HIV/HCV infection risk factor, CD4 cell count, and HIV-RNA viral load were not different between two groups. However, mean peak ALT of IHCVs was higher than comparators (776 vs. 237, P<0.001) and syphilis treatment within prior 24 months of ALT elevation was more common in IHCV group (41.7% vs. 12.7%, P=0.026). Conclusion Incidence rate of HCV among PLH revealed increasing trend between 2013 and 2022 among visitors at a HIV clinic in Korea. Subtype 1a dominated among IHCVs after 2020 and recent syphilis treatment was associated with IHCVs.