Maribavir for treatment of cytomegalovirus infection in a liver-transplanted patient.

Cytomegalovirus infection (CMV) can be fatal for organ transplant recipients as shown in this case report. Maribavir is a recently approved drug, which can be used for therapy-refractory CMV infection or when other treatment options cannot be used. The patient in this case report was a CMV-infected liver transplant recipient, who developed a severe erythema and high CMV DNA during valganciclovir therapy. Toxic epidermal necrolysis was suspected. The patient was treated with maribavir, and both CMV DNA and the skin normalised. This case illustrates that maribavir is a useful alternative to other antiviral drugs for CMV infection.

Evidence for Immunity against Tetanus, Diphtheria, and Pertussis through Natural Infection or Vaccination in Adult Solid Organ Transplant Recipients: A Systematic Review.

(1) Background: We aim to systematically review the current evidence on immunity against tetanus, diphtheria, and pertussis in adult solid organ transplantation (SOT) recipients, either through natural infection or vaccination. (2) Methods: This systematic review was conducted per PRISMA guidelines. We assessed the risk of bias using the Cochrane RoB 2 and ROBINS-I and summarized the findings narratively due to the heterogeneity of the studies. (3) Results: Of the 315 screened articles, 11 were included. Tetanus immunity varied between 55% and 86%, diphtheria immunity from 23% to 75%, and pertussis immunity was between 46% and 82%. Post-vaccination immunity showed variation across the studies, with some indicating reductions and others no change, with antibody responses influenced by transplanted organs, gender, age, and immunosuppressive regimens. The single randomized study exhibited a low risk of bias, while of the ten non-randomized studies, six showed moderate and four serious risks of bias, necessitating cautious interpretation of results. (4) Conclusions: SOT recipients exhibit considerable immunity against tetanus and diphtheria at transplantation, but this immunity decreases over time. Although vaccination can enhance this immunity, the response may be suboptimal, and the increased antibody levels may not persist, underscoring the need for tailored vaccination strategies in this vulnerable population.

Technique efficacy and complications after ablation as first surgical intervention for hepatocellular carcinoma: A nationwide database study.

INTRODUCTION: Despite limited evidence, technique efficacy and complications may be important short-term outcomes after ablation for hepatocellular carcinoma (HCC). We aimed to report these outcomes after ablation as the first surgical intervention for HCC. METHODS: This nationwide cohort study was based on data from the Danish Liver and Biliary Duct Cancer Database and medical records. Variables associated with outcomes were investigated using logistic regression. RESULTS: From 2013 to 2023, 433 patients were included of which 79% were male, 73% had one tumor, and 90% had cirrhosis. Complete ablation was achieved after percutaneous, laparoscopic, and open approach in 84%, 100%, and 96% of the procedures, respectively. Most patients did not experience complications (76%). Open ablation compared with percutaneous was associated with higher risk of complications in multivariable adjusted analysis (Clavien-Dindo grade 2-5 (odds ratio 5.34, 95% confidence interval [2.36; 12.08]) and 3B-5 (5.70, [2.03; 16.01]), and lower risk of incomplete ablation (0.19 [0.05; 0.65]). Number of tumors ≥3 was associated with a higher risk of incomplete ablation (3.88, [1.45; 10.41]). Tumor diameter ≥3 cm was associated with increased risk of complications grade 2-5 (2.84, [1.29; 6.26]) and 3B-5 (4.44, [1.62; 12.13]). Performance status ≥2 was associated with risk of complications grade 3B-5 (5.98, [1.58; 22.69]). Tumor diameter was not associated with technique efficacy. CONCLUSION: Open ablation had a higher rate of complete ablation compared with percutaneous but was associated with a higher risk of complications. Tumor diameter ≥3 cm and performance status ≥2 were associated with a higher risk of complications.

Self-reported symptom occurrence and distress, and psychological well-being after liver transplantation - a descriptive cross-sectional study of Danish recipients.

Introduction: Symptom distress and impaired psychological well-being after liver transplantation may lead to limitations in everyday activities and lowered health-related quality of life. The aim of this nationwide, descriptive, and cross-sectional study was to explore self-reported symptom occurrence and distress, among Danish liver transplant recipients, and their association with self-reported psychological well-being as well as demographic, and clinical characteristics. Methods: Liver transplant recipients transplanted from 1990 to 2022 were included. All recipients were asked to complete the Organ Transplant Symptom and Wellbeing instruments consisting of two instruments measuring self-reported symptom occurrence and distress, respectively, as well as self-reported psychological well-being by the Psychological General well-being instrument. Results: Of 511 invited recipients 238 responded: 116 women and 122 men with a median post-transplant follow-up of 7.5 years (IQR 3.6-14.2 years). The most common single symptoms reported were decreased libido (18%), diarrhea (10%), and headache (8%). Sleep problems were the most common transplant-specific domain. 41% of the recipients reported poor psychological well-being, especially those who had undergone transplantation within the last 5 years, women, and younger recipients. Discussion: In the interest of equity, the fact that women reported a higher level of symptom distress than men requires attention. Research on symptom management support is warranted with interventions focusing on how to alleviate symptom distress, which might increase long-term survival, which has not improved in recent decades.

Early Results of a Screening Program for Skin Cancer in Liver Transplant Recipients: A Cohort Study.

(1) Background: Skin cancer is the most common cancer in transplant recipients. Timely and regular screening may reduce advanced disease. The study aimed to determine referral rates to screening, the incidence, and risk factors of skin cancer in a Danish liver transplant recipient cohort. (2) Methods: All first-time liver transplant recipients, >18 years old, attending outpatient care between January 2018 and December 2021 were included. The referral rates and incidence of skin cancer/preneoplastic lesions were calculated. Risk factors were assessed using Cox regression analyses. (3) Results: Of the 246 included recipients, 219 (89.0%) were referred to screening, and 102 skin cancer/preneoplastic lesions were diagnosed in 32 (15.6%) recipients. The IR of any skin cancer/preneoplastic lesion was 103.2 per 1000 person-years. BCC was the most frequent skin cancer followed by SCC, IR: 51.3 vs. 27.1 per 1000 person-years, respectively. No cases of MM were observed. The IR of actinic keratosis and Bowen's Disease were 48.1 vs. 13.2 per 1000 person-years, respectively. Time since transplantation was independently associated with skin cancer/preneoplastic lesions, HR (95%CI) 2.81 (1.64-4.80). (4) Conclusions: The study determined the incidence and risk factors of skin cancer/preneoplastic lesions in liver transplant recipients enrolled in a screening program, while demonstrating a high screening referral rate.

Elevated plasma apolipoprotein E levels in people living with HIV: Associations with biomarkers and HIV-specific risk factors.

BACKGROUND AND AIMS: Apolipoprotein E (apoE) plays a crucial role in cholesterol metabolism, and high levels of apoE in plasma are associated with cardiovascular disease and all-cause mortality. We aimed to assess if HIV is independently associated with high plasma apoE and to determine HIV-related risk factors for high plasma apoE. METHODS: We included 661 people with HIV (PWH) from the Copenhagen Comorbidity in HIV (COCOMO) study with available measurement of plasma apoE. COCOMO participants were frequency matched 1:1 on age and sex with controls from the Copenhagen General Population Study. High plasma apoE was defined as levels above the 90th percentile (66.2 mg/L). The association between HIV and high plasma apoE was assessed using logistic regression models. Among PWH, both linear and logistic regression models were used to determine HIV-specific risk factors for high plasma apoE. RESULTS: Mean age was 52 years and 89 % were male. Median plasma apoE was 49.0 mg/L in PWH and 43.3 mg/L in controls, p < 0.001. HIV was associated with higher plasma apoE after adjusting for potential confounders, including triglycerides (odds ratio 2.14 [95 % CI: 1.39-3.29], p < 0.001). In PWH, higher plasma apoE was associated with a previous AIDS-defining condition in linear models before adjustment for triglycerides and integrase strand transfer inhibitor use in fully adjusted linear models. CONCLUSIONS: PWH had higher plasma apoE than controls even after adjusting for triglycerides. Further studies are needed to elucidate the clinical impact of high plasma apoE in PWH.

Immune responses to mRNA-based vaccines given as a third COVID-19 vaccine dose in people living with HIV-a literature review.

People living with HIV (PLWH) were not included in the first efficacy studies of mRNA vaccines against SARS-CoV-2. In this literature review, we investigate evidence of humoral and cellular immunity after a third dose of an mRNA vaccine in PLWH. We performed a literature search in PubMed, Embase, Web of Science and SCOPUS published between 1 January 2020 and 31 December 2022. Selection criteria were studies on immunological responses in PLWH, who were given an mRNA-based vaccine as a third vaccine dose against SARS-CoV-2. Eight articles complied with our selection criteria. All studies found a strong humoral response after the third dose. Five studies investigated cellular immunity and found an increased cellular response after the third vaccine dose in PLWH. No difference in humoral response was observed between PLWH and controls after three doses. However, some of the studies suggested a weaker cellular response among PLWH than in controls, which was associated with lower nadir or current CD4+ T-cell counts. In conclusion, we found evidence of strong humoral immunity in PLWH after receiving an mRNA-based COVID-19 vaccine as a third dose, while the cellular immunity may be impaired compared to controls.

Differences in toll-like receptor ligand-induced cytokine concentrations before and after solid organ transplantation: A prospective, observational cohort study in a clinical setting.

Reliable methods to assess immune function after solid organ transplantation (SOT) are needed to guide dosing of immunosuppression. We hypothesized that toll-like receptor ligand-induced cytokine concentrations would decrease post-transplantation due to the use of immunosuppressive medication. Furthermore, we hypothesized that induced cytokine concentrations pre-transplantation would be higher in recipients with episodes of acute rejection post-transplantation due to underlying immunological dispositions. We aimed to investigate toll-like receptor ligand-induced cytokine concentrations by TruCulture©, a standardized immunoassay, in SOT recipients before and 3 months after SOT and explored associations with methylprednisolone-treated acute rejections. We conducted a prospective, observational cohort study including 123 participants (67 liver, 32 kidney and 24 lung transplant recipients). Whole blood was stimulated for 22 h with: (A) Lipopolysaccharide (LPS), (B) Resiquimod, (C) Polyinosinic:polycytidylic acid (Poly I:C) and (D) a blank control. Cytokine concentrations (TNF-α, IL-1ß, IL-6, IL-8, IL-10, IL-12p40, IL-17A, IFN-α and IFN-γ) were measured by Luminex. 30 participants developed methylprednisolone-treated acute rejection at a median of 9 days (IQR 5-17) post-SOT. We found that all induced cytokine concentrations decreased post-SOT except from LPS-induced and Poly I:C-induced IL-10. The induced cytokine concentration pre-transplantation did not differ in recipients with or without acute rejection. In conclusion, the induced cytokine concentrations decreased for all stimuli post-SOT, except the anti-inflammatory cytokine IL-10. Importantly, recipients developing early acute rejection did not differ in induced cytokine concentrations pre-SOT. Thus, the use of a standardized assay in SOT is feasible in a clinical setting and may provide important information on the immune function post-SOT.

Gut Microbiota Alterations and Circulating Imidazole Propionate Levels Are Associated With Obstructive Coronary Artery Disease in People With HIV.

BACKGROUND: The impact of gut microbiota and its metabolites on coronary artery disease (CAD) in people with human immunodeficiency virus (PWH) is unknown. Emerging evidence suggests that imidazole propionate (ImP), a microbial metabolite, is linked with cardiometabolic diseases. METHODS: Fecal samples from participants of the Copenhagen Comorbidity in HIV infection (COCOMO) study were processed for 16S rRNA sequencing and ImP measured with liquid chromatography-tandem mass spectrometry. CAD severity was investigated by coronary computed tomography-angiography, and participants grouped according to obstructive CAD (n = 60), nonobstructive CAD (n = 80), or no CAD (n = 114). RESULTS: Participants with obstructive CAD had a gut microbiota with lower diversity and distinct compositional shift, with increased abundance of Rumiococcus gnavus and Veillonella, known producers of ImP. ImP plasma levels were associated with this dysbiosis, and significantly elevated in participants with obstructive CAD. However, gut dysbiosis but not plasma ImP was independently associated with obstructive CAD after adjustment for traditional and HIV-related risk factors (adjusted odds ratio, 2.7; 95% confidence interval, 1.1-7.2; P = .048). CONCLUSIONS: PWH with obstructive CAD displays a distinct gut microbiota profile and increased circulating ImP plasma levels. Future studies should determine whether gut dysbiosis and related metabolites such as ImP are predictive of incident cardiovascular events.

Anemia in liver transplant recipients: prevalence, severity, risk factors, and survival.

Information about anemia in liver transplant (LTx) recipients is scarce. We investigated the prevalence and severity of anemia before and within the first-year post-LTx, risk factors for having anemia before LTx, and 1-year survival according to anemia status before LTx. This retrospective cohort study received data from The Knowledge Center for Transplantation database at Rigshospitalet, Copenhagen, Denmark. Uni- and multivariate logistic regression were used to investigate factors associated with anemia and a Kaplan-Meier plot to illustrate the probability of survival. We included 346 first-time adult LTx recipients. The median age was 50 years (IQR: 42-57), and 203 (59%) were male. The prevalence of anemia before and 1-year post-LTx were 69 and 45%, respectively. Male sex (aOR 4.0 [95% CI: 2.2-7.2]; p < 0.001) and each unit increase in MELD score (aOR 1.2 [95% CI: 1.1-1.2]; p < 0.001) were positively associated with anemia before LTx. Compared to autoimmune liver diseases, LTx recipients with fulminant hepatic failure (aOR 0.03 [0.00-0.17]; p = 0.001) had lower odds for anemia. The 1-year survival in LTx recipients who had and did not have anemia before transplantation were 93 and 91% (p = 0.47). Anemia was frequent among LTx recipients, and anemia before LTx did not affect 1-year survival.

The Impact of Vaccination against SARS-CoV-2 on Health Outcomes and Hospital Visits after Omicron Infection in Children and Adolescents Aged 5-18 Years: A Danish Nation-Wide Cohort Study.

This study investigates the impact of vaccination against SARS-CoV-2 on health outcomes and hospital contacts in children and adolescents aged 5-18 years infected with the SARS-CoV-2 Omicron variant, comparing previously vaccinated with unvaccinated. Using national register data, vaccinated and unvaccinated Danish children and adolescents with a positive SARS-CoV-2 test between 1 January and 31 March 2022 (Omicron dominance period) were included. The Prior Event Rate Ratio (PERR) was used to explore differences in hospital contacts (hospitalizations and emergency room (ER) visits), while Inverse Treatment Probability Weighted (IPW) risk ratios were used to explore the risk of severe health outcomes within six weeks following SARS-CoV-2 infection. Vaccinated 5-11-year-old girls had fewer visits to the ER compared to unvaccinated ones, PERR 0.92 (95% CI 0.84-1.00). Vaccinated 5-11-year-old boys had fewer hospitalizations (PERR 0.79 (0.64-0.99)) and more ER visits (PERR 1.13 (1.04-1.22)) compared to unvaccinated ones. An unadjusted and significant lower risk of febrile seizure among vaccinated 5-11-year-olds compared to unvaccinated ones was found (risk ratio 0.12 (0.04-0.39), p ≤ 0.01. No significant differences were found for severe conditions or for croup or pneumonia in either age group. The results indicate a modest protective effect of the vaccine in terms of hospital contacts, but no protective effect on health outcomes after SARS-CoV-2 Omicron infection in this population of Danish children and adolescents.

The Interplay between Adipose Tissue Properties and Levels of NT-proBNP in People with HIV.

Objective: We aimed to assess the association between low N-terminal pro-brain natriuretic peptide (NT-proBNP) and body mass index (BMI), adipose tissue distribution, adiponectin, and HIV-specific risk factors among people with HIV (PWH). Methods: We included 811 PWH with measurement of height, weight and waist circumference, blood samples analyzed for NT-proBNP, and visceral-(VAT) and subcutaneous (SAT) adipose tissue areas measured from CT-scans. Low concentrations of NT-proBNP were defined as concentrations below the limit of quantification (5.9 pmol/L). Associations were explored with multivariable logistic regression analyses adjusted for relevant confounders. Results: We identified 471 (58%) individuals with low concentrations of NT-proBNP. Increasing BMI was associated with higher odds of low NT-proBNP (adjusted OR (aOR) 1.06 (95% CI: 1.01-1.11) per 1 kg/m2). Central obesity and large areas of VAT were associated with higher odds of low NT-proBNP (aOR 1.66 (1.16-2.36) and aOR 1.69 (1.09-2.62), respectively). Higher adiponectin was associated with lower odds of low NT-proBNP (aOR 0.86 (0.79-0.95) per 10% increase). No associations were found between low NT-proBNP and HIV-specific risk factors. Conclusions: In PWH, low NT-proBNP is associated with an adverse adipose tissue profile with high BMI, central obesity, accumulation of VAT, and low adiponectin.

Humoral immune response to COVID-19 vaccine in patients with myasthenia gravis.

We investigated the humoral response to the Pfizer-BioNTech COVID-19 (BNT162b2) vaccine in patients with myasthenia gravis on or off immunosuppressants and compared this to the response in healthy individuals. The SARS-CoV-2 IgG response and neutralizing capacity were measured in 83 patients (57 on immunosuppressants) and 332 healthy controls at baseline, three weeks, and two and six months after the vaccine. We found that the proportion of positive humoral response was lower in patients on immunosuppressants vs. controls at three weeks and two months (p ≤ 0.001), but not at six months post-vaccination (p = 0.379).

Herpes Virus Infections in Kidney Transplant Patients (HINT) - a prospective observational cohort study.

BACKGROUND: Kidney transplant recipients receive maintenance immunosuppressive therapy to avoid allograft rejection resulting in increased risk of infections and infection-related morbidity and mortality. Approximately 98% of adults are infected with varicella zoster virus, which upon reactivation causes herpes zoster. The incidence of herpes zoster is higher in kidney transplant recipients than in immunocompetent individuals, and kidney transplant recipients are at increased risk of severe herpes zoster-associated disease. Vaccination with adjuvanted recombinant glycoprotein E subunit herpes zoster vaccine (RZV) prevents herpes zoster in older adults with excellent efficacy (90%), and vaccination of kidney transplant candidates is recommended in Danish and international guidelines. However, the robustness and duration of immune responses after RZV vaccination, as well as the optimal timing of vaccination in relation to transplantation remain unanswered questions. Thus, the aim of this study is to characterize the immune response to RZV vaccination in kidney transplant candidates and recipients at different timepoints before and after transplantation. METHODS: The Herpes Virus Infections in Kidney Transplant Patients (HINT) study is a prospective observational cohort study. The study will include kidney transplant candidates on the waiting list for transplantation (n = 375) and kidney transplant recipients transplanted since January 1, 2019 (n = 500) from all Danish kidney transplant centers who are offered a RZV vaccine as routine care. Participants are followed with repeated blood sampling until 12 months after inclusion. In the case of transplantation or herpes zoster disease, additional blood samples will be collected until 12 months after transplantation. The immune response will be characterized by immunophenotyping and functional characterization of varicella zoster virus-specific T cells, by detection of anti-glycoprotein E antibodies, and by measuring cytokine profiles. DISCUSSION: The study will provide new knowledge on the immune response to RZV vaccination in kidney transplant candidates and recipients and the robustness and duration of the response, potentially enhancing preventive strategies against herpes zoster in a population at increased risk. TRIAL REGISTRATION: ClinicalTrials.gov (NCT05604911).

Previous immunity shapes immune responses to SARS-CoV-2 booster vaccination and Omicron breakthrough infection risk.

The heterogeneity of the SARS-CoV-2 immune responses has become considerably more complex over time and diverse immune imprinting is observed in vaccinated individuals. Despite vaccination, following the emergence of the Omicron variant, some individuals appear more susceptible to primary infections and reinfections than others, underscoring the need to elucidate how immune responses are influenced by previous infections and vaccination. IgG, IgA, neutralizing antibodies and T-cell immune responses in 1,325 individuals (955 of which were infection-naive) were investigated before and after three doses of the BNT162b2 vaccine, examining their relation to breakthrough infections and immune imprinting in the context of Omicron. Our study shows that both humoral and cellular responses following vaccination were generally higher after SARS-CoV-2 infection compared to infection-naive. Notably, viral exposure before vaccination was crucial to achieving a robust IgA response. Individuals with lower IgG, IgA, and neutralizing antibody responses postvaccination had a significantly higher risk of reinfection and future Omicron infections. This was not observed for T-cell responses. A primary infection before Omicron and subsequent reinfection with Omicron dampened the humoral and cellular responses compared to a primary Omicron infection, consistent with immune imprinting. These results underscore the significant impact of hybrid immunity for immune responses in general, particularly for IgA responses even after revaccination, and the importance of robust humoral responses in preventing future infections.

Distinguishing SARS-CoV-2 infection and vaccine responses up to 18 months post-infection using nucleocapsid protein and receptor-binding domain antibodies.

The prediction of the durability of immunity against COVID-19 is relevant, and longitudinal studies are essential for unraveling the details regarding protective SARS-CoV-2 antibody responses. It has become challenging to discriminate between COVID-19 vaccine- and infection-induced immune responses since all approved vaccines in Europe and the USA are based on the viral spike (S) protein, which is also the most commonly used antigen in immunoassays measuring immunoglobulins (Igs) against SARS-CoV-2. We have developed a nucleocapsid (N) protein-based sandwich ELISA for detecting pan anti-SARS-CoV-2 Ig with a sensitivity and specificity of 97%. Generalized mixed models were used to determine the degree of long-term humoral immunity against the N protein and the receptor-binding domain (RBD) of the S protein in a cohort of infected individuals to distinguish between COVID-19 vaccine- and infection-induced immunity. N-specific waning could be observed in individuals who did not experience reinfection, while individuals who experienced reinfection had a new significant increase in N-specific Ig levels. In individuals that seroconverted without a reinfection, 70.1% remained anti-N seropositive after 550 days. The anti-RBD Ig dynamics were unaffected by reinfection but exhibited a clear increase in RBD-specific Ig when vaccination was initiated. In conclusion, a clear difference in the dynamics of the antibody response against N protein and RBD was observed over time. Anti-N protein-specific Igs can be detected up to 18 months after SARS-CoV-2 infection allowing long-term discrimination of infectious and vaccine antibody responses.IMPORTANCELongitudinal studies are essential to unravel details regarding the protective antibody responses after COVID-19 infection and vaccination. It has become challenging to distinguish long-term immune responses to SARS-CoV-2 infection and vaccination since most approved vaccines are based on the viral spike (S) protein, which is also mostly used in immunoassays measuring immunoglobulins (Igs) against SARS-CoV-2. We have developed a novel nucleocapsid (N) protein-based sandwich ELISA for detecting pan-anti-SARS-CoV-2 Ig, exhibiting high sensitivity and specificity. Generalized mixed models were used to determine long-term humoral immunity in a cohort of infected individuals from the Faroe Islands, distinguishing between COVID-19 vaccine- and infection-induced immunity. A clear difference in the dynamics of the antibody response against N protein and S protein was observed over time, and the anti-N protein-specific Igs could be detected up to 18 months after SARS-CoV-2 infection. This enables long-term discrimination between natural infection and vaccine-dependent antibody responses.

Risk of New-onset Type 1 Diabetes in Danish Children and Adolescents After SARS-CoV-2 Infection: A Nationwide, Matched Cohort Study.

We investigated the association between SARS-CoV-2 infection and new-onset type 1 diabetes (T1D) in children and adolescents in a nationwide, matched cohort study. The hazard ratio of new-onset T1D within 6 months after SARS-CoV-2 infection was 1.22 (0.58-2.58). The risk of new-onset T1D in children and adolescents was not significantly increased after SARS-CoV-2 infection.

Peripheral T-cell activation, Th17 cells, regulatory T-cells, and aortic aneurysm in people with HIV.

Here, we investigate if peripheral T-cell activation and proportion of Th17 and T-regulatory cells (Tregs) are associated with aortic aneurysm or aortic diameter in people with HIV. Aorta was examined by computed tomography scans and T-cells by flow cytometry in 428 participants, and aortic aneurysm was found in 32 participants. None of the T-cell subsets were associated with aortic aneurysm, but activated T-cells and Tregs had opposite association to aorta diameter indicating an inverse impact.

Mpox Incidence and Vaccine Uptake in Men Who Have Sex with Men and Are Living with HIV in Denmark.

(1) Background: Here, we investigate the incidence of mpox and factors associated with vaccine uptake in mainly well-treated men who have sex with men and are living with HIV (MSMWH). (2) Methods: This study included 727 MSMWH from the Copenhagen co-morbidity in HIV infection (COCOMO) study from 1 May to 31 October 2022. Mpox infection and vaccination status were obtained from the Danish Microbiology Database and The Danish Vaccination Register. Vaccination willingness was assessed through an online survey. (3) Results: At a median follow-up of 180 days, 13 (1.8%) participants had laboratory-confirmed mpox infections. Furthermore, 238 (32.7%) had received the mpox vaccine. A sexually transmitted disease (STD) in the preceding two years was associated with a higher risk of mpox infection (hazard ratio 7.1; 95% confidence interval (CI) [1.9-26.9]) and with higher odds of vaccination (adjusted odds ratio 3.1; 95% CI [2.2-4.6]). 401 (55.2%) participants responded to the survey. 228 (57.0%) reported very high vaccination willingness. The self-perceived risk of infection was associated with vaccine uptake. (4) Conclusions: The incidence of mpox was low. A prior STD was associated with both a higher risk of mpox infection and higher odds of vaccination. Despite high-risk sexual behavior and high vaccination willingness, a sizable fraction of participants had not been vaccinated.