High-dose valacyclovir HSV-2 suppression results in greater reduction in plasma HIV-1 levels compared with standard dose acyclovir among HIV-1/HSV-2 coinfected persons: a randomized, crossover trial

Combination therapy synergism prediction for virus treatment using machine learning models

Combining different drugs synergistically is an essential aspect of developing effective treatments. Although there is a plethora of research on computational prediction for new combination therapies, there is limited to no research on combination therapies in the treatment of viral diseases. This paper proposes AI-based models for predicting novel antiviral combinations to treat virus diseases synergistically. To do this, we assembled a comprehensive dataset comprising information on viral strains, drug compounds, and their known interactions. As far as we know, this is the first dataset and learning model on combination therapy for viruses. Our proposal includes using a random forest model, an SVM model, and a deep model to train viral combination therapy. The machine learning models showed the highest performance, and the predicted values were validated by a t-test, indicating the effectiveness of the proposed methods. One of the predicted combinations of acyclovir and ribavirin has been experimentally confirmed to have a synergistic antiviral effect against herpes simplex type-1 virus, as described in the literature.

20 years of herpes simplex virus type 2 (HSV-2) research in low-income and middle-income countries: systematic evaluation of progress made in addressing WHO priorities for research in HSV-2/HIV interactions, HSV-2 control and mathematical modelling

INTRODUCTION

Reviewing and updating research priorities is essential to assess progress and to ensure optimal allocation of financial and human resources in research. In 2001, WHO held a research priority setting workshop for herpes simplex virus type 2 (HSV-2) research in low-income and middle-income countries (LMICs). This study aimed to describe progress between 2000 and 2020 in three of the five key research priority areas outlined in the workshop: HSV-2/HIV interactions, HSV-2 control measures and HSV-2 mathematical modelling. The remaining priorities are addressed in a companion paper.

METHOD

A systematic literature search of MEDLINE, CINAHL, Global Health and Cochrane databases was carried out. Relevant primary research studies based in LMICs, written in English and published on 2000-2020 were included. Papers were screened by two independent reviewers, and suitable variables were selected for manual extraction from study texts. Data were organised into an Excel spreadsheet and analysed using IBM SPSS.

RESULTS

In total, 3214 discrete papers were identified, of which 180 were eligible for inclusion (HSV-2/HIV interactions, 98; control measures, 58; mathematical modelling, 24). Most studies were conducted in East Africa. The majority of the 2001 WHO HSV-2 research priorities were addressed at least in part. Overall, despite several studies describing a strong relationship between HSV-2 and the acquisition and transmission of HIV, HSV-2 control repeatedly demonstrated little effect on HIV shedding or transmission. Further, although mathematical modelling predicted that vaccines could significantly impact HSV-2 indicators, HSV-2 vaccine studies were few. Studies of antiviral resistance were also few.

CONCLUSION

Since 2000, LMIC HSV-2 research addressing its control, HIV interactions and mathematical modelling has largely addressed the priorities set in the 2001 WHO HSV-2 workshop. However, key knowledge gaps remain in vaccine research, antiviral cost-effectiveness, antiviral resistance and specific geographical areas.

Cervical Cytology and Herpes Simplex Virus Type-2 Serology Among Human Immune Deficiency Virus Infected Women on Highly Active Antiretroviral Therapy in Enugu, Nigeria

BACKGROUND

The prevalence of Human Immunodeficiency Virus (HIV) and Herpes Simplex Virus type-2 (HSV-2) infections are high and the programme for Cervical Cancer Screening is weak in Nigeria.

OBJECTIVES

Prevalence of Herpes Simplex Virus Type-2 co-infection and cervical cytology among HSV-2 co-infected Human Immunodeficiency Virus Sero-positive (HIV+) women on Highly Active Antiretroviral Therapy (HAART) attending Human Immunodeficiency Virus clinic at University of Nigeria Teaching Hospital (UNTH) Ituku/Ozalla Enugu, Nigeria.

METHODS

A cross-sectional, hospital-based study. Active participants included 105 HIV seropositive women on HAART and104 HIV seronegative (HIV-) women who passed inclusion criteria and signed written informed consent. Each participant was coded with a specific number. A structured questionnaire was used to obtain the socio-demographic and medical history. Serum was obtained for HSV-2 serology test for all participants and HIV screening for HIV-negative participants. Cervical smears were collected for Papanicolaou stains and Immunocytochemistry using anti-P16INKa antibody.

RESULTS

Prevalence of HSV-2+ was 50.5% among HIV+ women on HAART and 16.3% among HIV- women, Odds Ratios [95% CI]; p-value was 5.21 [2.74-9.94]; p < 0.0001. HIV+ women on HAART co-infected with HSV-2 significantly had more Cervical Lesions, 11.4% compared to HIVwomen uninfected with HSV-2, 4.8%, OR [95% CI]; p-value 4.8 (1.58-14.54); p = 0.006.

CONCLUSION

The prevalence of HSV-2 was significantly high among HIV+ women on HAART. HSV-2+ co-infection could be an enhancer of Cervical Lesions among HIV+ women on HAART. Hence, anti-herpetic agent introduction and screening for HSV-2 among HIV+ patients are recommended.

Sexually transmitted infections and HIV in the era of antiretroviral treatment and prevention: the biologic basis for epidemiologic synergy

INTRODUCTION

HIV is a unique sexually transmitted infection (STI) that is greatly affected by other concomitant "classical" bacterial and viral STIs that cause genital ulcers and/or mucosal inflammation. STIs also serve as a marker for risky sexual behaviours. STIs increase infectiousness of people living with HIV by increasing the viral concentration in the genital tract, and by increasing the potential for HIV acquisition in people at risk for HIV. In addition, some STIs can increase blood HIV concentration and promote progression of disease. This review is designed to investigate the complex relationship between HIV and classical STIs.

DISCUSSION

Treatment of STIs with appropriate antibiotics reduces HIV in blood, semen and female genital secretions. However, community-based trials could not reliably reduce the spread of HIV by mass treatment of STIs. Introduction of antiretroviral agents for the treatment and prevention of HIV has led to renewed interest in the complex relationship between STIs and HIV. Antiretroviral treatment (ART) reduces the infectiousness of HIV and virtually eliminates the transmission of HIV in spite of concomitant or acquired STIs. However, while ART interrupts HIV transmission, it does not stop intermittent shedding of HIV in genital secretions. Such shedding of HIV is increased by STIs, although the viral copies are not likely replication competent or infectious. Pre-exposure prophylaxis (PrEP) of HIV with the combination of tenofovir disoproxil fumarate and emtricitabine (TDF/FTC) prevents HIV acquisition in spite of concomitant STIs.

CONCLUSIONS

STIs remain pandemic, and the availability of ART may have led to an increase in STIs, as fear of HIV has diminished. Classical STIs present a huge worldwide health burden that cannot be separated from HIV, and they deserve far more attention than they currently receive.

Modeling HIV disease progression and transmission at population-level: The potential impact of modifying disease progression in HIV treatment programs

INTRODUCTION

Mathematical models that incorporate HIV disease progression dynamics can estimate the potential impact of strategies that delay HIV disease progression and reduce infectiousness for persons not on antiretroviral therapy (ART). Suppressive treatment of HIV-positive persons co-infected with herpes simplex virus-2 (HSV-2) with valacyclovir, an HSV-2 antiviral, can lower HIV viral load, but the impact of partially-suppressive valacyclovir relative to fully-suppressive ART on population HIV transmission has not been estimated.

METHODS

We modeled HIV disease progression as a function of changes in viral load and CD4 count over time among ART naïve persons. The disease progression Markov model was nested within a dynamic model of HIV transmission at population level. We assumed that valacyclovir reduced HIV viral load by 1.23 log copies/μL, and that persons treated with valacyclovir initiated ART more rapidly when their CD4 fell below 500 due to retention in HIV care. We estimated the potential impact of valacyclovir on onward transmission of HIV in three scenarios of different ART and valacyclovir population coverage.

RESULTS

The average duration of HIV infection was 9.5 years. The duration of disease before reaching CD4 200cells/μL was 2.53 years longer for females than males. Relative to a baseline of ART initiation at CD4≤500cells/μL, the valacyclovir scenario resulted in 167,000 fewer HIV infections over ten years, with an incremental cost-effectiveness ratio (ICER) of $5276 per HIV infection averted. A Test and Treat scenario with 70% ART coverage and no valacyclovir resulted in 350,000 fewer HIV infections at an ICER of $2822 and $812 per HIV infection averted and QALY gained, respectively.

CONCLUSION

Even when compared with valacyclovir suppression, a drug that reduces HIV viral load, universal treatment for HIV is the optimal strategy for averting new infections and increasing public health benefit. Universal HIV treatment would most effectively and efficiently reduce the HIV burden.

Seroprevalence of Herpes Simplex Virus type-2 (HSV-2) among pregnant women who participated in a national HIV surveillance activity in Haiti

BACKGROUND

Herpes simplex virus type 2 (HSV-2), one the most common causes of genital ulcers, appears to increase both the risk of HIV acquisition and HIV transmission. HSV-2/HIV co-infection among pregnant women may increase the risk of perinatal transmission of HIV. This study describes rates of HSV-2 among pregnant women in Haiti and HSV-2 test performance in this population.

METHODS

Unlinked residual serum specimens from the 2012 National HIV and Syphilis Sentinel Surveillance Survey among pregnant women in Haiti were tested using two commercial kits (Focus HerpeSelect, Kalon) for HSV-2 antibodies. We evaluated rates of HSV-2 seropositivity and HSV-2/HIV co-infection, associations between HSV-2 and demographic characteristics using multivariable Cox proportional hazards modeling, and HSV-2 test performance in this population.

RESULTS

Serum samples from 1000 pregnant women (all 164 HIV positive and 836 random HIV negative) were selected. The overall weighted prevalence of HSV-2 was 31.4% (95% CI: 27.7-35.4) and the prevalence of HIV-positivity among HSV-2 positive pregnant women was five times higher than the prevalence among HSV-2 negative women (4.8% [95% CI: 3.9-6.0] vs. 0.9% [95% CI: 0.6-1.3], respectively). Factors significantly associated with HSV-2 positivity were HIV-positivity (PR: 2.27 [95% CI: 1.94-2.65]) and older age (PRs: 1.41 [95% CI: 1.05-1.91] for 20-24 years, 1.71 [95% CI:1.13-2.60] for 30-34 years, and 1.55 [95% CI: 1.10-2.19] for 35 years or greater]), while rural residence was negatively associated with HSV-2 positivity (PR 0.83 [95% CI: 0.69-1.00]), after controlling for other covariables. For this study a conservative Focus index cutoff of 3.5 was used, but among samples with a Focus index value ≥2.5, 98.4% had positive Kalon tests.

CONCLUSION

The prevalence of HSV-2 is relatively high among pregnant women in Haiti. Public health interventions to increase access to HSV-2 screening in antenatal services are warranted.

Current Concepts for Genital Herpes Simplex Virus Infection: Diagnostics and Pathogenesis of Genital Tract Shedding

Herpes simplex virus 2 (HSV-2) is a DNA virus that is efficiently transmitted through intimate genital tract contact and causes persistent infection that cannot be eliminated. HSV-2 may cause frequent, symptomatic self-limited genital ulcers, but in most persons infection is subclinical. However, recent studies have demonstrated that the virus is frequently shed from genital surfaces even in the absence of signs or symptoms of clinical disease and that the virus can be transmitted during these periods of shedding. Furthermore, HSV-2 shedding is detected throughout the genital tract and may be associated with genital tract inflammation, which likely contributes to increased risk of HIV acquisition. This review focuses on HSV diagnostics, as well as what we have learned about the importance of frequent genital HSV shedding for (i) HSV transmission and (ii) genital tract inflammation, as well as (iii) the impact of HSV-2 infection on HIV acquisition and transmission. We conclude with discussion of future areas of research to push the field forward.

Decreased monocyte activation with daily acyclovir use in HIV-1/HSV-2 coinfected women

OBJECTIVES

Several clinical trials have demonstrated that daily treatment of HIV-infected individuals with the antiherpes drug acyclovir slightly decreases HIV-1 viral load and slows disease progression. This study examines if this slowing in clinical progression is a direct cause of the decrease in viral load or an indirect effect of lower immune activation due to lower levels of herpetic reactivation.

METHODS

Women who participated in a randomised clinical trial of daily acyclovir use (n=301) were monitored every 6 months for changes in immune activation. Soluble CD14 (sCD14), a marker for monocyte activation, and C-reactive protein (CRP), a marker for general immune activation, were measured by ELISA.

RESULTS

Initial levels of sCD14 and CRP were not predictive of HIV disease progression when controlling for initial CD4+ cell count and HIV viral load. sCD14 levels, but not CRP, decreased in the acyclovir treatment arm at a significantly faster rate than the placebo group, which was independent of changes in HIV viral load and CD4+ cell count in a multivariant mixed-effects model (p=0.039). However, the magnitude of this decrease was relatively small with a total estimated decrease of sCD14 of 15% of initial levels.

CONCLUSIONS

These data suggest that decreased monocyte activation may play a minor role in the ability of daily acyclovir use to slow HIV disease progression.

CLINICAL TRIAL REGISTRATION NUMBER

NCT00405821.

Brief report: HIV-1 transmissions during asymptomatic infection: exploring the impact of changes in HIV-1 viral load due to coinfections

Supplemental Digital Content is Available in the Text.

High HIV-1 plasma viral loads (PVLs) in sub-Saharan Africa, partly because of high rates of coinfection, may have been one of the drivers of the “explosive” epidemics seen in that region. Using a previously published framework of infectiousness and survival, we estimate the excess onward HIV-1 transmission events (secondary infections) resulting from coinfection-induced changes in PVL during asymptomatic HIV-1 infection. For every 100 HIV-infected people, each suffering 1 episode of tuberculosis infection, there are 4.9 (2.7th–97.5th percentile: 0.2–21.5) excess onward HIV-1 transmission events attributable to this coinfection. Other estimates are malaria 0.4 (0.0–2.0), soil-transmitted helminths 3.1 (0.1–14.9), schistosomiasis 8.5 (0.2–38.6), filariasis 13.3 (0.3–89.2), syphilis 0.1 (0.0–1.6), herpes simplex virus 4.0 (0.0–24.2), and gonorrhea 2.1 (0.1–8.0) transmissions. If these higher PVLs confer a shorter life expectancy and higher infectiousness, then their impact on transmission is, in general, reduced. For most HIV-1 coinfections, the duration of a single infection is too short and/or the associated PVL elevation is too modest to contribute substantially to onward HIV-1 transmission.

Integrating prevention interventions for people living with HIV into care and treatment programs: a systematic review of the evidence

INTRODUCTION

This review assesses the impact of prevention interventions for people living with HIV on HIV-related mortality, morbidity, retention in care, quality of life, and prevention of ongoing HIV transmission in resource-limited settings (RLSs).

METHODS

We conducted a systematic review of studies reporting the results of prevention interventions for people living with HIV in RLS published between January 2000 and August 2014. Standardized methods of searching and data abstraction were used.

RESULTS

Ninety-two studies met the eligibility criteria: 24 articles related to adherence counseling and support, 13 on risk reduction education and condom provision, 19 on partner HIV testing and counseling, 14 on provision of family planning services, and 22 on assessment and treatment of other sexually transmitted infections. Findings indicate good evidence that adherence counseling and sexually transmitted infection treatment can have a high impact on morbidity, whereas risk reduction education, partner HIV testing and counseling, and family planning counseling can prevent transmission of HIV. More limited evidence was found to support the impact of these interventions on retention in care and quality of life. Most studies did not report cost information, making it difficult to draw conclusions about the cost-effectiveness of these interventions.

CONCLUSIONS

This evidence suggests that these prevention interventions, if brought to sufficient scale and coverage, can help support and optimize the impact of core treatment and prevention interventions in RLS. Further operational research with more rigorous study designs, and ideally with biomarkers and costing information, is needed to determine the best model for providing these interventions in RLS.

Valacyclovir Decreases Plasma HIV-1 RNA in HSV-2 Seronegative Individuals: A Randomized Placebo-Controlled Crossover Trial

BACKGROUND

Acyclovir (ACV), a highly specific anti-herpetic drug, acts as a DNA chain terminator for several human herpesviruses (HHVs), including HHV-2 (HSV-2), a common human immunodeficiency virus (HIV)-1 co-pathogen. Several trials demonstrated that HSV-2 suppressive therapy using ACV or its prodrug valacyclovir (valACV) reduced plasma HIV-1 viral load (VL) in HIV-1/HSV-2 coinfected persons, and this was proposed to be due to a decrease in generalized immune activation. Recently, however, we found that ACV directly suppresses HIV-1 ex vivo in tissues free of HSV-2 but endogenously coinfected with other HHVs. Here, we asked whether valACV suppresses VL in HIV-1 infected HSV-2-seronegative persons.

METHODS

Eighteen HIV-1 infected HSV-2-seronegative individuals were randomly assigned in a double blind placebo-controlled, crossover trial. Eligible participants had CD4 cell counts of ≥500 cells/µL and were not taking antiretroviral therapy. Subjects in group A received 12 weeks of valACV 500 mg given twice daily by mouth followed by 2 weeks of a no treatment washout and then 12 weeks of placebo; subjects in group B received 12 weeks of placebo followed by 2 weeks of no treatment washout and then 12 weeks of valACV 500 mg twice daily.

RESULTS

HIV-1 VL in plasma of patients treated with valACV 500 mg twice daily for 12 weeks was reduced on average by 0.37 log10 copies/mL.

CONCLUSIONS

These data indicate that the effects of valACV on HIV-1 replication are not related to the suppression of HSV-2-mediated inflammation and are consistent with a direct effect of ACV on HIV-1 replication.

HIV infection: epidemiology, pathogenesis, treatment, and prevention

HIV prevalence is increasing worldwide because people on antiretroviral therapy are living longer, although new infections decreased from 3.3 million in 2002, to 2.3 million in 2012. Global AIDS-related deaths peaked at 2.3 million in 2005, and decreased to 1.6 million by 2012. An estimated 9.7 million people in low-income and middle-income countries had started antiretroviral therapy by 2012. New insights into the mechanisms of latent infection and the importance of reservoirs of infection might eventually lead to a cure. The role of immune activation in the pathogenesis of non-AIDS clinical events (major causes of morbidity and mortality in people on antiretroviral therapy) is receiving increased recognition. Breakthroughs in the prevention of HIV important to public health include male medical circumcision, antiretrovirals to prevent mother-to-child transmission, antiretroviral therapy in people with HIV to prevent transmission, and antiretrovirals for pre-exposure prophylaxis. Research into other prevention interventions, notably vaccines and vaginal microbicides, is in progress.

Impact of CMV therapy with valganciclovir on immune activation and the HIV viral load in semen and blood: an observational clinical study

BACKGROUND

The HIV RNA viral load (VL) in vaginal secretions and semen is an independent predictor of HIV transmission. Blood VL is associated with semen VL, and local mucosal factors, such as semen cytomegalovirus (CMV) reactivation, may play an important role.

METHODS

Twenty-one HIV-CMV-coinfected, antiretroviral-naive men received 900 mg of oral valganciclovir once daily for 2 weeks in an open-label study. Blood and semen were collected at baseline, after 2 weeks of valganciclovir, and 2 months after therapy completion. The primary end point was change in semen HIV levels at 2 weeks, and the secondary end points were change in semen HIV VL at 2 months and change in semen CMV levels.

RESULTS

The HIV VLs fell significantly at 2 weeks in semen (median 3.44-3.02 log10 copies/mL, P = 0.02) and blood (median 3.61-3.10 log10 copies/mL, P < 0.01) and returned to baseline after therapy completion (median 3.24 and 3.71 log10 copies/mL in semen and blood, respectively). Semen CMV levels also fell on treatment (median 2.13-1.62 log10 copies/mL, P < 0.01) and continued to fall after therapy completion (median 0.91 log10 copies/mL at week 8, P < 0.001 vs. baseline). The reduced semen CMV VL was associated with decreased semen T-cell activation and enhanced CMV-specific T-cell responses in blood; changes in the semen HIV VL were not associated with immune parameters.

CONCLUSIONS

Although valganciclovir therapy was associated with reduced HIV and semen CMV levels, these results suggest that the reduced HIV VL was a direct drug effect rather than a CMV antiviral effect or CMV-associated immune alterations.

Medical male circumcision and herpes simplex virus 2 acquisition: posttrial surveillance in Kisumu, Kenya

BACKGROUND

We estimated the 72-month efficacy of medical male circumcision (MMC) against herpes simplex virus 2 (HSV-2) incidence among men in the Kisumu MMC randomized trial.

METHODS

From 2002 to 2005, 2784 men aged 18-24 were enrolled and randomized 1:1 to immediate circumcision or control. Cox proportional hazards regression incorporating stabilized inverse probability of treatment and censoring weights generated through marginal structural modeling was used to estimate the efficacy of MMC on HSV-2 risk. Conventional conditional Cox regression identified multivariable risks for HSV-2 seroconversion.

RESULTS

Among 2044 HSV-2 seronegative men at baseline, the cumulative 72-month HSV-2 incidence was 33.5% (32.7% among circumcised men, 34.6% among uncircumcised men). In weight-adjusted Cox regression, the hazard ratio was 0.88 (95% confidence interval, .77-1.10). In multivariable analyses, risks for HSV-2 included human immunodeficiency virus (HIV) infection, genital ulcer disease (GUD), penile epithelial trauma, multiple recent sex partners, and being married /cohabiting.

CONCLUSIONS

MMC had no effect on acquisition of HSV-2 during 72 months of follow-up. The temporal sequence and limited correlation between HSV-2, GUD, and penile epithelial trauma suggests that these are distinct phenomena rather than misclassification of HSV-2 symptoms. Determining the etiology of non-sexually transmitted infection GUD and penile epithelial trauma is needed, as both are commonly occurring risks for HSV-2 and HIV acquisition.

CLINICAL TRIALS REGISTRATION

NCT0005937.

Summary measures of adherence using pill counts in two HIV prevention trials: the need for standardisation in reporting

For trials of user-dependent HIV prevention products, accurate adherence measurements are essential to interpret and compare results across trials. We used pill count data from two recent HIV prevention trials of herpes simplex virus type 2 (HSV-2) suppression, to show that estimates of adherence vary substantially depending on assumptions that are made in analysing pill count data. We associate calculated adherence with biological markers of anti-HSV-2 activity. In both trials, calculated adherence varied considerably, depending on the summary measure used, and the handling of intervals with apparent ‘over-adherence’ (fewer pills returned than expected), and unreturned pills. Intervals of apparent over-adherence were associated with reduced antiviral effects on biological markers of herpes reactivation, indicating these are likely to represent periods of non-adherence. Our results demonstrate the clear need for standardisation in reporting of adherence data that are based on pill counts.

Herpes simplex virus type 2 and HIV disease progression: a systematic review of observational studies

Background

Herpes simplex virus type 2 (HSV-2) is a common co-infection among HIV-infected adults that is hypothesized to accelerate HIV disease progression.

Methods

We searched Medline, EMBASE, relevant conference proceedings (2006–12) and bibliographies of identified studies without language restriction for cohort studies examining the impact of HSV-2 on highly active antiretroviral therapy-untreated HIV disease in adults. The exposure of interest was HSV-2 seropositivity or clinical/laboratory markers of HSV-2 activity. The primary outcome was HIV disease progression, defined as antiretroviral initiation, development of AIDS/opportunistic infection, or progression to CD4 count thresholds (≤200 or ≤350 cells/mm³). Secondary outcomes included HIV plasma viral load and CD4 count.

Results

Seven studies were included. No definitive relationship was observed between HSV-2 seropositivity and time to antiretroviral initiation (n=2 studies), CD4≤350 (n=1), CD4≤200 (n=1), death (n=1), viral load (n=6) or CD4 count (n=3). Although two studies each observed trends towards accelerated progression to clinical AIDS/opportunistic infection in HSV-2 seropositives, with pooled unadjusted hazard ratio=1.85 (95% CI=1.12,3.06; I²=2%), most OIs observed in the study for which data were available can occur at high CD4 counts and may not represent HIV progression. In contrast, a single study HSV-2 disease activity found that the presence of genital HSV-2 DNA was associated with a 0.4 log copies/mL increase in HIV viral load.

Conclusions

Despite an observation that HSV-2 activity is associated with increased HIV viral load, definitive evidence linking HSV-2 seropositivity to accelerated HIV disease progression is lacking. The attenuating effects of acyclovir on HIV disease progression observed in recent trials may result both from direct anti-HIV activity as well as from indirect benefits of HSV-2 suppression.

A multi-targeted drug candidate with dual anti-HIV and anti-HSV activity

Human immunodeficiency virus (HIV) infection is often accompanied by infection with other pathogens, in particular herpes simplex virus type 2 (HSV-2). The resulting coinfection is involved in a vicious circle of mutual facilitations. Therefore, an important task is to develop a compound that is highly potent against both viruses to suppress their transmission and replication. Here, we report on the discovery of such a compound, designated PMEO-DAPym. We compared its properties with those of the structurally related and clinically used acyclic nucleoside phosphonates (ANPs) tenofovir and adefovir. We demonstrated the potent anti-HIV and -HSV activity of this drug in a diverse set of clinically relevant in vitro, ex vivo, and in vivo systems including (i) CD4⁺ T-lymphocyte (CEM) cell cultures, (ii) embryonic lung (HEL) cell cultures, (iii) organotypic epithelial raft cultures of primary human keratinocytes (PHKs), (iv) primary human monocyte/macrophage (M/M) cell cultures, (v) human ex vivo lymphoid tissue, and (vi) athymic nude mice. Upon conversion to its diphosphate metabolite, PMEO-DAPym markedly inhibits both HIV-1 reverse transcriptase (RT) and HSV DNA polymerase. However, in striking contrast to tenofovir and adefovir, it also acts as an efficient immunomodulator, inducing β-chemokines in PBMC cultures, in particular the CCR5 agonists MIP-1β, MIP-1α and RANTES but not the CXCR4 agonist SDF-1, without the need to be intracellularly metabolized. Such specific β-chemokine upregulation required new mRNA synthesis. The upregulation of β-chemokines was shown to be associated with a pronounced downmodulation of the HIV-1 coreceptor CCR5 which may result in prevention of HIV entry. PMEO-DAPym belongs conceptually to a new class of efficient multitargeted antivirals for concomitant dual-viral (HSV/HIV) infection therapy through inhibition of virus-specific pathways (i.e. the viral polymerases) and HIV transmission prevention through interference with host pathways (i.e. CCR5 receptor down regulation).

To contain the HIV-1 epidemic, it is necessary to develop antivirals that prevent HIV-1 transmission. It is well known that HIV infection might be accompanied by other pathogens, which often are engaged with HIV-1 in a vicious circle of mutual facilitation. One of the most common of these pathogens is herpes simplex virus (HSV) type 2. Since there is an urgent need for a next generation antivirals that are multi-targeted, we can now report on the development of the first antiviral of this new generation that efficiently suppresses both HIV-1 and HSV-2. We found that the dual-targeted antiviral drug affects several targets for viral replication. It uniquely combines in one molecule three important abilities: (i) to efficiently suppress HSV-encoded DNA polymerase, (ii) to efficiently suppress HIV-1-encoded reverse transcriptase, and (iii) to stimulate secretion of CC-chemokines that downregulate the HIV-1 coreceptor CCR5. The compound suppresses both viruses in a wide-range of in vitro, ex vivo, and in vivo experimental models. The ability of one molecule to suppress HIV-1 and HSV-2 by combining direct activity against their two key enzymes and indirect immunomodulatory effects is unique in the antiviral field.

Translation of biomedical prevention strategies for HIV: prospects and pitfalls

Early achievements in biomedical approaches for HIV prevention included physical barriers (condoms), clean injection equipment (both for medical use and for injection drug users), blood and blood product safety, and prevention of mother-to-child transmission. In recent years, antiretroviral drugs to reduce the risk of transmission (when the infected person takes the medicines; treatment as prevention) or reduce the risk of acquisition (when the seronegative person takes them; preexposure prophylaxis) have proven to be efficacious. Circumcision of men has also been a major tool relevant for higher prevalence regions such as sub-Saharan Africa. Well-established prevention strategies in the control of sexually transmitted diseases and tuberculosis are highly relevant for HIV (ie, screening, linkage to care, early treatment, and contact tracing). Unfortunately, only slow progress is being made in some available HIV-prevention strategies such as family planning for HIV-infected women who do not want more children and prevention of mother-to-child HIV transmission. Current studies seek to integrate strategies into approaches that combine biomedical, behavioral, and structural methods to achieve prevention synergies. This review identifies the major biomedical approaches demonstrated to be efficacious that are now available. We also highlight the need for behavioral risk reduction and adherence as essential components of any biomedical approach.

The Role of Sexually Transmitted Infections in HIV-1 Progression: A Comprehensive Review of the Literature

Due to shared routes of infection, HIV-infected persons are frequently coinfected with other sexually transmitted infections (STIs). Studies have demonstrated the bidirectional relationships between HIV and several STIs, including herpes simplex virus-2 (HSV-2), hepatitis B and C viruses, human papilloma virus, syphilis, gonorrhea, chlamydia, and trichomonas. HIV-1 may affect the clinical presentation, treatment outcome, and progression of STIs, such as syphilis, HSV-2, and hepatitis B and C viruses. Likewise, the presence of an STI may increase both genital and plasma HIV-1 RNA levels, enhancing the transmissibility of HIV-1, with important public health implications. Regarding the effect of STIs on HIV-1 progression, the most studied interrelationship has been with HIV-1/HSV-2 coinfection, with recent studies showing that antiherpetic medications slow the time to CD4 <200 cells/µL and antiretroviral therapy among coinfected patients. The impact of other chronic STIs (hepatitis B and C) on HIV-1 progression requires further study, but some studies have shown increased mortality rates. Treatable, nonchronic STIs (i.e., syphilis, gonorrhea, chlamydia, and trichomonas) typically have no or transient impacts on plasma HIV RNA levels that resolve with antimicrobial therapy; no long-term effects on outcomes have been shown. Future studies are advocated to continue investigating the complex interplay between HIV-1 and other STIs.

High-dose valacyclovir decreases plasma HIV-1 RNA more than standard-dose acyclovir in persons coinfected with HIV-1 and HSV-2: a randomized crossover trial

BACKGROUND

Standard doses of herpes simplex virus (HSV) suppressive therapy reduce plasma HIV-1 RNA levels (0.25-0.53 log10 copies per milliliter) among HIV-1/HSV-2 coinfected persons. Postulated mechanisms for this effect include direct inhibition of HIV-1 by acyclovir or indirect reduction by decreasing HSV-associated inflammation. We hypothesized that high-dose valacyclovir would further reduce plasma HIV-1 RNA and that the effect would be mediated by greater suppression of HSV shedding.

METHODS

Thirty-four participants with HIV-1 and HSV-2 not on antiretroviral therapy were enrolled into a randomized, open-label crossover trial of valacyclovir 1000 mg twice daily or acyclovir 400 mg twice daily for 12 weeks, followed by a 2-week washout, and then the alternate treatment arm for 12 weeks. HSV DNA was measured from daily self-collected genital swabs for the initial 4 weeks of each arm, and HIV-1 RNA was quantified from weekly plasma samples.

RESULTS

Twenty-eight participants provided plasma samples and genital swabs on both acyclovir and valacyclovir. The genital HSV-2 shedding rate was the same on valacyclovir and acyclovir [7.8% vs. 8.2% of days; relative risk: 0.95; 95% confidence interval (CI): 0.66 to 1.37; P = 0.78]. Plasma HIV-1 RNA was 0.27 log10 copies per milliliter lower on valacyclovir compared with acyclovir (95% CI: -0.41 to -0.14 log10 copies per milliliter; P < 0.001); this was unchanged after adjustment for genital HSV-2 shedding.

CONCLUSIONS

High-dose valacyclovir reduces plasma HIV-1 RNA levels more than standard-dose acyclovir in HIV-1/HSV-2-seropositive persons not receiving antiretroviral therapy. The incremental reduction in plasma HIV-1 RNA achieved is not mediated by greater genital HSV-2 suppression.

Selective anti-herpesvirus agents

This review article focuses on the anti-herpesvirus agents effective against herpes simplex virus, varicella-zoster virus and cytomegalovirus, which have either been licensed for clinical use (idoxuridine, trifluridine, brivudin, acyclovir, valaciclovir, valganciclovir, famciclovir and foscarnet) or are under clinical development (CMX001 [the hexadecyloxypropyl prodrug of cidofovir], the helicase-primase inhibitor BAY 57-1293 [now referred to as AIC316], FV-100 [the valine ester of Cf 1743] and the terminase inhibitor letermovir [AIC246]).

Design and implementation of a randomized crossover study of valproic acid and antiretroviral therapy to reduce the HIV reservoir

BACKGROUND

HIV reservoirs represent the major obstacles for eradication and are defined as a cell type that allows persistence of replication-competent HIV in patients on optimal long-term antiretroviral therapy (HAART). Several pilot clinical trials have been implemented to assess the value of experimental therapy to reduce reservoir size or eradicate HIV. In order to eradicate HIV, valproic acid was used as a new strategy to increase viral gene expression in the nucleus of infected cells with the expectation of generating a direct cell death or destruction by nearby cytotoxic cells. Previous pilot studies using VPA have showed conflicting results on the ability of VPA to reduce the size of HIV reservoirs.

PURPOSE

As the role of VPA on HIV reservoirs remains unclear, we conducted a multicenter clinical trial with a specific study design to obtain optimal information on reservoir changes while exposing the smallest number of individuals to the experimental medication.

METHOD

To this aim, a randomized, crossover design with 2 different treatment durations was implemented. By doubling the therapeutic period in one study arm, we were in a position to assess the impact of an extended duration of VPA on the size of the HIV reservoir and to evaluate the duration of treatment effects upon VPA withdrawal in the other arm. However, limitations for this type of study design included the logistical complexity of 2 uneven study arms and longer study duration.

CONCLUSION

Despite the absence of demonstrable impact of VPA on reservoir size, such crossover study design should be considered in the early stage testing of novel HIV therapeutics targeted to reduce reservoir size or eradicate HIV.

Burden of disease associated with human cytomegalovirus and prospects for elimination by universal immunisation

Cytomegalovirus is the most frequent cause of intrauterine infection and the commonest infectious agent to affect allograft recipients, yet the virus is acknowledged rarely as an occupational hazard for women of childbearing age or as a nosocomial infection. The potential role of cytomegalovirus in hastening the death of patients with AIDS, elderly people, individuals admitted to intensive-care units, and the general population is not emphasised. Development of vaccines against this important human pathogen has been delayed by reluctance to initiate proof-of-concept studies, but after recent trials, protection is a distinct possibility. Cytomegalovirus deserves to be eliminated from selected populations by means of universal immunisation as soon as suitable vaccines become licensed. This action should control disease in neonates and transplant recipients and could provide substantial additional benefits if other disease associations prove to be causal.

Human viral diseases: what is next for antiviral drug discovery?

For the treatment of human immunodeficiency virus (HIV) infections for which there are ample drugs available, the immediate future lies in a once-daily combination pill containing three or four active ingredients. This strategy may also be envisaged for the treatment of hepatitis C virus (HCV) infections as soon as we have at hand the appropriate direct-acting antiviral agents (DAAs) to be combined. A combination drug therapy is generally not entertained for other viruses. Yet, new drugs are at the horizon for the treatment of herpes simplex virus (HSV), varicella-zoster virus (VZV), poxvirus, hepatitis B virus (HBV), influenza and enveloped viruses-at-large.

HIV-1 prevention for HIV-1 serodiscordant couples

A substantial proportion of HIV-1 infected individuals in sub-Saharan Africa are in stable relationships with HIV-1 uninfected partners, and HIV-1 serodiscordant couples thus represent an important target population for HIV-1 prevention. Couple-based HIV-1 testing and counseling facilitates identification of HIV-1 serodiscordant couples, counseling about risk reduction, and referrals to HIV-1 treatment, reproductive health services, and support services. Maximizing HIV-1 prevention for HIV-1 serodiscordant couples requires a combination of strategies, including counseling about condoms, sexual risk, fertility, contraception, and the clinical and prevention benefits of antiretroviral therapy (ART) for the HIV-1-infected partner; provision of clinical care and ART for the HIV-1-infected partner; antenatal care and services to prevent mother-to-child transmission for HIV-1-infected pregnant women; male circumcision for HIV-1-uninfected men; and, pending guidelines and demonstration projects, oral pre-exposure prophylaxis (PrEP) for HIV-1-uninfected partners.

Effects of valacyclovir on markers of disease progression in postpartum women co-infected with HIV-1 and herpes simplex virus-2

Objective

Herpes simplex virus type 2 (HSV-2) suppression has been shown to reduce HIV-1 disease progression in non-pregnant women and men, but effects on pregnant and postpartum women have not been described.

Methods

We analyzed data from a cohort of Kenyan women participating in a randomized clinical trial of HSV-2 suppression. Pregnant HIV-1-seropositive, HSV-2-seropositive women who were not eligible for antiretroviral therapy (WHO stage 1–2, CD4>250 cells/µl) were randomized to either 500 mg valacyclovir or placebo twice daily from 34 weeks gestation through 12 months postpartum. Women received zidovudine and single-dose nevirapine for prevention of mother-to-child HIV-1 transmission. HIV-1 progression markers, including CD4 count and plasma HIV-1 RNA levels, were measured serially. Multivariate linear regression was used to compare progression markers between study arms.

Results

Of 148 women randomized, 136 (92%) completed 12 months of postpartum follow-up. While adjusted mean CD4 count at 12 months (565 cells/µl placebo arm, 638 cells/µl valacyclovir arm) increased from antenatal levels in both arms, the mean CD4 count increase was 73 cells/µl higher in the valacyclovir arm than placebo arm (p = 0.03). Mean increase in CD4 count was 154 cells/µl in the valacyclovir arm, almost double the increase of 78 cells/µl in the placebo arm. At 12 months, adjusted HIV-1 RNA levels in the placebo arm increased by 0.66 log₁₀ copies/ml from baseline, and increased by only 0.21 log₁₀ copies/ml in the valacyclovir arm (0.40 log₁₀ copies/ml difference, p = 0.001).

Conclusion

Women randomized to valacyclovir suppressive therapy during pregnancy and postpartum had greater increases in CD4 counts and smaller increases in plasma HIV-1 RNA levels than women in the placebo arm. Valacyclovir suppression during pregnancy and breastfeeding may improve outcomes and delay antiretroviral therapy for HIV-1/HSV-2 co-infected women.

Effect of daily aciclovir on HIV disease progression in individuals in Rakai, Uganda, co-infected with HIV-1 and herpes simplex virus type 2: a randomised, double-blind placebo-controlled trial

BACKGROUND

Daily suppression of herpes simplex virus type 2 (HSV-2) reduces plasma HIV-1 concentrations and modestly delayed HIV-1 disease progression in one clinical trial. We investigated the effect of daily suppressive aciclovir on HIV-1 disease progression in Rakai, Uganda.

METHODS

We did a single site, parallel, randomised, controlled trial of HIV-1, HSV-2 dually infected adults with CD4 cell counts of 300-400 cells per μL. We excluded individuals who had an AIDS-defining illness or active genital ulcer disease, and those that were taking antiretroviral therapy. Participants were randomly assigned (1:1) with computer-generated random numbers in blocks of four to receive either aciclovir 400 mg orally twice daily or placebo; participants were followed up for 24 months. All study staff and participants were masked to treatment, except for the two statisticians. The primary outcome was CD4 cell count less than 250 cells per μL or initiation of antiretroviral therapy for WHO stage 4 disease. Our intention-to-treat analysis used Cox proportional hazards models, adjusting for baseline log(10) viral load, CD4 cell count, sex, and age to assess the risk of disease progression. We also investigated the effect of suppressive HSV-2 treatment stratified by baseline HIV viral load with a Cox proportional hazards model. This trial is registered with ClinicalTrials.gov, number NCT00405821.

FINDINGS

440 participants were randomly assigned, 220 to each group. 110 participants in the placebo group and 95 participants in the treatment group reached the primary endpoint (adjusted hazard ratio [HR] 0·75, 95% CI 0·58-0·99; p=0·040). 24 participants in the placebo group and 22 in the treatment group were censored, but all contributed data for the final analysis. In a subanalysis stratified by baseline HIV viral load, participants with a baseline viral load of 50,000 copies mL or more in the treatment group had a reduced HIV disease progression compared with those in the placebo group (0·62, 0·43-0·96; p=0·03). No significant difference in HIV disease progression existed between participants in the treatment group and those in the placebo group who had baseline HIV viral loads of less than 50,000 copies per mL (0·90, 0·54-1·5; p=0·688). No safety issues related to aciclovir treatment were identified.

INTERPRETATION

Aciclovir reduces the rate of disease progression, with the greatest effect in individuals with a high baseline viral load. Suppressive aciclovir might be warranted for individuals dually infected with HSV-2 and HIV-1 with viral loads of 50,000 copies per mL or more before initiation of antiretroviral treatment.

FUNDING

National Institute of Allergy and Infectious Diseases, National Cancer Institute (National Institutes of Health, USA).

Infectious co-factors in HIV-1 transmission herpes simplex virus type-2 and HIV-1: new insights and interventions

Over the last thirty years, epidemiologic and molecular studies indicate a strong and synergist relationship between the dual epidemics of herpes simplex type 2 (HSV-2) and HIV-1 infection. While prospective studies show that HSV-2 infection increases the risk for HIV-1 acquisition by 2- to 3-fold, HSV-2 suppression with standard prophylactic doses of HSV-2 therapy did not prevent HIV-1 acquisition. Reconciling these discrepancies requires understanding recent HSV-2 pathogenesis research, which indicates HSV-2 infection is not a latent infection with infrequent recurrence but a near constant state of reactivation and viral shedding which is not completely suppressed by standard antivirals. Because current antivirals do not prevent or fully suppress HSV-2 replication, priorities are HSV-2 vaccine development and antivirals that reach high concentrations in the genital mucosa and suppress the persistent genital inflammation associated with genital herpes reactivation in order to reduce the increased susceptibility to HIV-1 infection associated with HSV-2. HIV-1 and HSV-2 synergy is also seen among co-infected individuals who exhibit higher HIV-1 viral load compared to HSV-2 uninfected individuals. Standard HSV-2 therapy modestly lowers HIV-1 viral load and is associated with slower HIV-1 disease progression. A promising area of research is higher doses of HSV-2 suppressive therapy achieving a greater reduction in plasma HIV-1 RNA, which could translate to greater reductions in HIV-1 disease progression and infectiousness. However, many questions remain to be answered including potential effectiveness and cost-effectiveness of higher dose HSV-2 suppressive therapy. Mathematical models of HSV-2 and HIV-1 at a population level would be useful tools to estimate the potential impact and cost-effectiveness of higher dose HSV-2 suppressive therapy.

Exploiting the anti-HIV-1 activity of acyclovir: suppression of primary and drug-resistant HIV isolates and potentiation of the activity by ribavirin

Multiple clinical trials have demonstrated that herpes simplex virus 2 (HSV-2) suppressive therapy using acyclovir (ACV) or valacyclovir in HIV-1/HSV-2-infected persons increased the patient's survival and decreased the HIV-1 load. It has been shown that the incorporation of ACV-monophosphate into the nascent DNA chain instead of dGMP results in the termination of viral DNA elongation and directly inhibits laboratory strains of HIV-1. We evaluated here the anti-HIV activity of ACV against primary HIV-1 isolates of different clades and coreceptor specificity and against viral isolates resistant to currently used drugs, including zidovudine, lamivudine, nevirapine, a combination of nucleoside reverse transcriptase inhibitors (NRTIs), a fusion inhibitor, and two protease inhibitors. We found that, at clinically relevant concentrations, ACV inhibits the replication of these isolates in human tissues infected ex vivo. Moreover, addition of ribavirin, an antiviral capable of depleting the pool of intracellular dGTP, potentiated the ACV-mediated HIV-1 suppression. These data warrant further clinical investigations of the benefits of using inexpensive and safe ACV alone or in combination with other drugs against HIV-1, especially to complement or delay highly active antiretroviral therapy (HAART) initiation in low-resource settings.