Assessing the feasibility of hepatitis C virus vaccine trials: Results from the Hepatitis C Incidence and Transmission Study-community (HITS-c) vaccine preparedness study

Efficacy trials of preventive hepatitis C virus (HCV) vaccine candidates raise challenging scientific and ethical issues. Based on data from the first 3 years of a community-based prospective observational study – the Hepatitis C Incidence and Transmission Study-community (HITS-c) – this paper examines the feasibility of conducting trials of candidate HCV vaccines with people who inject drugs (PWID) in Sydney, Australia. Of the 166 PWID confirmed HCV antibody negative and eligible for enrolment, 156 (94%) completed baseline procedures. Retention was high, with 89% of participants retained at 48 weeks and 76% of participants completing at least 75% of study visits within 2 weeks of schedule. The rate of primary HCV infection was 7.9/100 py (95% CI 4.9, 12.7). Of the 17 incident cases, 16 completed at least one follow-up assessment and 12 (75%) had evidence of chronic viraemia with progression to chronic HCV infection estimated to be 6/100 py. Power calculations suggest a chronic HCV infection rate of at least 12/100 py (primary HCV infection rate 16/100 py) will be required for stand-alone trials of highly efficacious candidates designed to prevent chronic infection. However, elevated primary HCV infection was observed among participants not receiving opioid substitution therapy who reported heroin as the main drug injected (26.9/100 py, 95% CI 14.5, 50.0) and those who reported unstable housing (23.5/100 py, 95% CI 7.6, 72.8), daily or more frequent injecting (22.7/100 py, 95% CI 12.2, 42.2) and receptive syringe sharing (23.6/100 py, 95% CI 9.8, 56.7) in the 6 months prior to baseline. These data suggest that it is possible to recruit and retain at-risk PWID who adhere to study protocols and that modification of eligibility criteria may identify populations with sufficiently high HCV incidence. Results support the feasibility of large multi-centre HCV vaccine trials, including in the Australian setting.     

Preferences for Long-Acting and Alternative Modalities for PrEP among Military Men Who Have Sex with Men: Segmentation Results of an Adaptive Choice-Based Conjoint Analysis Study

The use of pre-exposure prophylaxis (PrEP) for HIV prevention within the U.S. military is low. Implementing preference-based alternative modalities of PrEP delivery, however, can be an innovative strategy to address the specific barriers to PrEP uptake among military MSM. We sought to identify population-based, segment-specific preferences for longer-acting and alternative PrEP delivery modalities to guide patient-centered strategies to optimize uptake within military-serving healthcare systems. HIV-negative military men who have sex with men (MSM) completed an anonymous, adaptive choice-based conjoint (ACBC) analysis survey consisting of five key attributes of interest (dosing method, provider type, visit location, lab work evaluation location, and dispensing venue). Relative importance and part-worth utility scores were generated using Hierarchical Bayes (HB) estimation, and cluster ensemble analysis grouped participants into “phenotype” segments by preference similarity. The randomized first-choice model was then used to examine changes in program interest rates among segments through market simulation. The 429 participants were segmented into five preference groups. The dosing method attribute was found to be the most important to nearly all segments. Simulations revealed that PrEP program interest among two segments with low interest levels increased when smartphone, civilian-based, and long-acting injectable PrEP options were involved. Findings also suggested a need for clinics to be responsive and sensitive to sexual practices, risk perception, and functional PrEP knowledge. Responsiveness to segment-specific preferences in the design of military PrEP programs and acting on the importance of clinical relationships within the context of PrEP engagement within a military setting may contribute to increasing PrEP uptake.     

Interactive Effects of Maternal Vitamin D Status and Socio-Economic Status on the Risk of Spontaneous Abortion: Evidence from Henan Province,China

Background: Maternal vitamin D deficiency might generate adverse reproductive outcomes, and socio-economic inequalities in micronutrient-related diseases have often been found. This study aimed to explore the interactive effects of maternal vitamin D status and socio-economic status (SES) on risk of spontaneous abortion. Methods: A population-based case–control study was conducted including 293 women with spontaneous abortion and 498 control women in December 2009 and January, 2010 in Henan Province, China. Information on pregnancy outcomes, maternal demographic, lifestyle and exposure factors and blood samples were collected at the same time. Vitamin D deficiency was defined as 25(OH)D < 20 ng/mL. SES index was constructed with principal component analysis by aggregating women’s and their husbands’ education level and occupation, and household income and expenditure. Interactive effects were assessed on a multiplicative scale with ratio of the odds ratio (ROR). Results: Compared to those with high SES and vitamin D sufficiency, women with vitamin D deficiency and low SES index had an increased risk of spontaneous abortion (aOR: 1.99; 95% CI: 1.23–3.23). The ROR was 2.06 (95% CI: 1.04–4.10), indicating a significant positive multiplicative interaction. Conclusions: Maternal low SES may strengthen the effect of vitamin D deficiency exposure on spontaneous abortion risk in this Chinese population.     

Prevalence of Hepatitis C, HIV, and Risk Behaviors for Blood-Borne Infections: A Population-Based Survey of the Adult Population of T'bilisi, Republic of Georgia

Injection drug use and associated hepatitis C virus (HCV) and HIV infections are on the rise in Russia and the republics of the former Soviet Union. While small targeted studies have found widespread drug use and disease among at-risk populations, there have been few attempts to comprehensively evaluate the extent of these epidemics in general post-Soviet societies. We conducted a two-stage cluster randomized survey of the entire adult population of T'bilisi, Republic of Georgia and assessed the burden of HCV, HIV, and risk behaviors for blood-borne infections in 2,000 study participants. Of the 2,000 surveyed individuals, 162 (8.1%) had injected illicit drugs during their lifetimes. Of the individuals who had injected illicit drugs, 138 (85.2%) reported sharing needles with injection partners. HCV was found in 134 (6.7%) of the total surveyed population, but in 114 (70.4%) of those who had injected illicit drugs. We found HIV in only three (0.2%) individuals, all of whom had injected illicit drugs. Injection drug use and high-risk injection practices are very common in Georgia and may be harbingers of a large burden of HCV-associated liver diseases and a potentially serious HIV epidemic in the years to come. Stvilia, Tsertsvadze, Sharvadze, and Aladashvili are with the Georgian AIDS and Clinical Immunology Research Center, T'bilisi, Republic of Georgia; Rio is with the Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA; Kuniholm and Nelson are with the Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe St., Baltimore, MD 21205, USA; Nelson is with the Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD, USA.