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Background Mycoplasma genitalium (MG) infection is a public health concern due to antimicrobial resistance (AMR). Data are limited on repeat MG infection and AMR among US Air Force service members with HIV. Methods US Air Force service members seeking HIV care were screened for MG infection during the surveillance period (16 May 2016–16 March 2020). Baseline and repeat MG prevalence rates were estimated. An extended Cox proportional hazards regression model evaluated characteristics associated with repeat MG infection. MG-positive rectal samples were tested for macrolide or fluoroquinolone resistance. Results Among 299 male patients from a total of 308 patients followed during the surveillance period, baseline prevalence of MG infection was 19.7% (n = 59); among the 101 patients who screened positive for MG at any time during the surveillance period, repeat MG was 35% (n = 36). Characteristics independently associated with increased risk of repeat infection were sexually transmitted infection history vs none (adjusted hazard ratio [aHR], 2.33; 95% CI, 1.26–4.31), a sexually transmitted infection coinfection vs no positive test result in the medical records (aHR, 5.13; 95% CI, 2.78–9.49), and a new HIV diagnosis (<1 vs ≥1 year; aHR, 2.63; 95% CI, 1.45–3.73). AMR in MG-positive rectal specimens was 88% (43/49) indicating macrolide resistance, 18% (10/56) quinolone resistance, and 18% (10/56) both. Conclusions Macrolide and fluoroquinolone resistance mutations were common. Testing for co-occurring MG infection and AMR mutations may be warranted in guiding treatment for sexually transmitted infections such as chlamydia or gonorrhea detected at HIV diagnosis. [ABSTRACT FROM AUTHOR]

Infusion of the broadly neutralizing antibody VRC01 has been evaluated in individuals chronically infected with HIV-1. Here, we studied how VRC01 infusions affected viral rebound after cessation of antiretroviral therapy (ART) in 18 acutely treated and durably suppressed individuals. Viral rebound occurred in all individuals, yet VRC01 infusions modestly delayed rebound and participants who showed a faster decay of VRC01 in serum rebounded more rapidly. Participants with strains most sensitive to VRC01 or with VRC01 epitope motifs similar to known VRC01- susceptible strains rebounded later. Upon rebound, HIV-1 sequences were indistinguishable from those sampled at diagnosis. Across the cohort, participant-derived Env showed different sensitivity to VRC01 neutralization (including 2 resistant viruses), yet neutralization sensitivity was similar at diagnosis and after rebound, indicating the lack of selection for VRC01 resistance during treatment interruption. Our results showed that viremia rebounded despite the absence of HIV-1 adaptation to VRC01 and an average VRC01 trough of 221 micro]g/mL. Although VRC01 levels were insufficient to prevent a resurgent infection, knowledge that they did not mediate Env mutations in acute-like viruses is relevant for antibody-based strategies in acute infection., Introduction Analytic treatment interruption (ATI) studies can help evaluate strategies to mediate long-term remission in HIV-1-infected persons. An ATI study tested the impact of the administration of the broadly neutralizing [...]

Introduction: Thailand plays a substantial role in global HIV-1 transmission of CRF01_AE. Worldwide, men who have sex with men (MSM) are at elevated risk for HIV-1 infection. Hence, understanding HIV-1 diversity in a primarily Thai MSM cohort with acute infection, and its connections to the broader HIV-1 transmission network in Asia is crucial for research and development of HIV-1 vaccines, treatment and cure. Methods: Subtypes and diversity of infecting viruses from individuals sampled from 2009 to 2015 within the RV254/SEARCH 010 cohort were assessed by multiregion hybridization assay (MHAbce), multiregion subtype-specific PCR assay (MSSPbce) and full-length single-genome sequencing (SGS). Phylogenetic analysis was performed by maximum likelihood. Pairwise genetic distances of envelope gp160 sequences obtained from the cohort and from Asia (Los Alamos National Laboratory HIV Database) were calculated to identify potential transmission networks. Results: MHAbce/MSSPbce results identified 81.6% CRF01AE infecting strains in RV254. CRF01AE/B recombinants and sub-type B were found at 7.3% and 2.8% respectively. Western subtype B strains outnumbered Thai B' strains. Phylogenetic analysis revealed one C, one CRF01_AE/CRF02_AG recombinant and one CRF01_AE/B/C recombinant. Asian network analysis identified one hundred and twenty-three clusters, including five clusters of RV254 participants. None of the RV254 sequences clustered with non-RV254 sequences. The largest international cluster involved 15 CRF01AE strains from China and Vietnam. The remaining clusters were mostly intracountry connections, of which 31.7% included Thai nodes and 43.1% included Chinese nodes. Conclusion: While the majority of strains in Thailand are CRF01AE and subtype B, emergence of unique recombinant forms (URFs) are found in a moderate fraction of new HIV-1 infections. Approaches to vaccine design and immunotherapeutics will need to monitor and consider the expanding proportion of recombinants and the increasing genetic diversity in the region. Identified HIV-1 transmission networks indicate ongoing spread of HIV-1 among MSM. As HIV-1 epidemics continue to expand in other Asian countries, transmission network analyses can inform strategies for prevention, intervention, treatment and cure. Keywords: HIV-1 molecular epidemiology; Thailand; Asia transmission network; MSM; acute infection; recombinants; vaccine; intervention, Additional Supporting Information may be found online in the Supporting information tab for this article. 1 INTRODUCTION Over 30 years have passed since the first case of HIV-1 was reported [...]

Subtype B HIV-1 has been the primary driver of the HIV-1 epidemic in the United States (U.S.) for over forty years and is also a prominent subtype in the Americas, Europe, Australia, the Middle East and North Africa. In this study, the neutralization profiles of contemporary subtype B Envs from the U.S. were assessed to characterize changes in neutralization sensitivities over time. We generated a panel of 30 contemporary pseudoviruses (PSVs) and demonstrated continued diversification of subtype B Env from the 1980s up to 2018. Neutralization sensitivities of the contemporary subtype B PSVs were characterized using 31 neutralizing antibodies (NAbs) and were compared with strains from earlier in the HIV-1 pandemic. A significant reduction in Env neutralization sensitivity was observed for 27 out of 31 NAbs for the contemporary as compared to earlier-decade subtype B PSVs. A decline in neutralization sensitivity was observed across all Env domains; the NAbs that were most potent early in the pandemic suffered the greatest decline in potency over time. A meta-analysis demonstrated this trend across multiple subtypes. As HIV-1 Env diversification continues, changes in Env antigenicity and neutralization sensitivity should continue to be evaluated to inform the development of improved vaccine and antibody products to prevent and treat HIV-1. Author summary: HIV-1 has evolved and diversified over the last forty years of the pandemic. These changes have shifted viral properties in such a way that the effectiveness of current therapeutic HIV-specific broadly neutralizing antibodies may be reduced over time. Understanding these changes will allow for the development of improved vaccine and antibody products. In this study, we generated a panel of 30 HIV-1 strains from the United States from samples collected between 2017 and 2018. We characterized the sensitivity of these contemporary HIV-1 strains using 31 antibodies that can inhibit, or neutralize, infection and compared the results to those of viruses from earlier in the pandemic. Our results show that antibodies that were effective against HIV-1 strains from earlier in the pandemic are not as effective against current HIV-1 strains. This trend in reduced sensitivity over time is occurring globally, as similar results were observed in Thailand and Africa. These results will inform the development of more effective antibodies and vaccines to elicit them. [ABSTRACT FROM AUTHOR]

Host restriction factors play key roles in innate antiviral defense, but it remains poorly understood which of them restricts HIV-1 in vivo. Here, we used single-cell transcriptomic analysis to identify host factors associated with HIV-1 control during acute infection by correlating host gene expression with viral RNA abundance within individual cells. Wide sequencing of cells from one participant with the highest plasma viral load revealed that intracellular viral RNA transcription correlates inversely with expression of the gene PTMA, which encodes prothymosin α. This association was genome-wide significant (Padjusted < 0.05) and was validated in 28 additional participants from Thailand and the Americas with HIV-1 CRF01_AE and subtype B infections, respectively. Overexpression of prothymosin α in vitro confirmed that this cellular factor inhibits HIV-1 transcription and infectious virus production. Our results identify prothymosin α as a host factor that restricts HIV-1 infection in vivo, which has implications for viral transmission and cure strategies. Editor's summary: Identifying factors that restrict human immunodeficiency virus (HIV)–1 replication in vivo may inform potential cure strategies for people living with HIV-1. Here, Geretz et al. analyzed transcripts from both the host and virus within the same single cells to identify host transcripts associated with lower HIV-1 RNA. Using samples from a person living with HIV-1, the authors identified prothymosin α as one such host restriction factor, which they validated in 28 additional participants. Further, overexpression of prothymosin α was sufficient to restrict HIV-1 replication in vitro. These data demonstrate that prothymosin α is a host restriction factor and suggest that it may represent a target for HIV-1 cure strategies. —Courtney Malo [ABSTRACT FROM AUTHOR]

: Introduction: Men who have sex with men (MSM), and transgender women (TGW), face specific obstacles to retention in care, particularly in settings with stigmatization such as sub‐Saharan Africa. We evaluated the impacts of HIV status and other factors on loss‐to‐follow‐up (LTFU) and visit adherence among MSM and TGW in Abuja and Lagos, Nigeria. Methods: TRUST/RV368 is an open cohort that provides comprehensive and integrated prevention and treatment services for HIV and sexually transmitted infections (STIs) at community venues supportive of sexual and gender minorities. Recruitment began in March 2013 and participants were followed every three months for up to 18 months. LTFU was defined as not presenting for an expected visit in the past 180 days. Visit adherence was calculated as a rate of completed visits adjusted by the number of three‐month intervals elapsed since enrolment. HIV and other factors predictive of LTFU and visit adherence were evaluated using Cox proportional hazards and Poisson regression models, respectively. Results: A total of 1447 participants who completed enrolment evaluations over two visits as of November 2018 were included in these analyses. Their median age was 24 years (interquartile range [IQR]: 21 to 28) and 53% (n = 766) were living with HIV. LTFU occurred in 56% (n = 808) and visit adherence was 0.62 (95% confidence interval: 0.61 to 0.64) visits per three‐month interval. Participants at risk and living with HIV had median follow‐up times of 12 months (IQR: 6 to 22), and 21 months (IQR: 12 to 30), respectively (p < 0.01). After controlling for other factors, LTFU was less common among participants living with HIV or other STIs and more common among those who did not own a cell phone, sold sex and had never undergone HIV testing prior to enrolment. These factors had parallel associations with visit adherence. Conclusions: Retention was suboptimal in Nigerian clinics designed to serve MSM and TGW. Particularly high LTFU and low visit adherence among participants at risk for HIV could complicate deployment of HIV prevention interventions. Marketing the benefits of testing, improving access to cell phones and nurturing more trust with clients may improve retention among marginalized communities in Nigeria., INTRODUCTION Retention of people at risk for and living with HIV (PLWH) in evidence‐based programmes has its challenges in countries across sub‐Saharan Africa where loss to follow‐up (LTFU) estimates range [...]

Eliciting broadly neutralizing antibodies (bnAbs) is a cornerstone of HIV-1 vaccine strategies. Comparing HIV-1 envelope (env) sequences from the first weeks of infection to the breadth of antibody responses observed several years after infection can help define viral features critical to vaccine design. We investigated the relationship between HIV-1 env genetics and the development of neutralization breadth in 70 individuals enrolled in a prospective acute HIV-1 cohort. Half of the individuals who developed bnAbs were infected with multiple HIV-1 founder variants, whereas all individuals with limited neutralization breadth had been infected with single HIV-1 founders. Accordingly, at HIV-1 diagnosis, env diversity was significantly higher in participants who later developed bnAbs compared to those with limited breadth (p = 0.012). This association between founder multiplicity and the subsequent development of neutralization breadth was also observed in 56 placebo recipients in the RV144 vaccine efficacy trial. In addition, we found no evidence that neutralization breath was heritable when analyzing env sequences from the 126 participants. These results demonstrate that the presence of slightly different HIV-1 variants in acute infection could promote the induction of bnAbs, suggesting a novel vaccine strategy, whereby an initial immunization with a cocktail of minimally distant antigens would be able to initiate bnAb development towards breadth. Author summary: Vaccines against viral pathogens protect through the induction of broadly neutralizing antibodies (bnAbs). No HIV-1 vaccine has successfully elicited bnAbs, and a successful HIV-1 vaccine will need to accelerate the process of development of a broadly neutralizing response that typically takes a couple of years to develop in natural infection. We studied diversity in the HIV-1 envelope gene from initial infection to several years out in 126 individuals from two cohorts. We showed that the development of bnAbs at 2–3 years was not due to transmissible viral genetics, but rather associated with diversity during the first month of infection. We propose that designing a vaccine that mimics an infection with multiple, minimally distant founder variants may successfully elicit the development of bnAbs and provide effective prophylaxis against HIV-1. [ABSTRACT FROM AUTHOR]

The scale of the HIV-1 epidemic underscores the need for a vaccine. The multitude of circulating HIV-1 strains together with HIV-1's high evolvability hints that HIV-1 could adapt to a future vaccine. Here, we wanted to investigate the effect of vaccination on the evolution of the virus post-breakthrough infection. We analyzed 2,635 HIV-1 env sequences sampled up to a year post-diagnosis from 110 vaccine and placebo participants who became infected in the RV144 vaccine efficacy trial. We showed that the Env signature sites that were previously identified to distinguish vaccine and placebo participants were maintained over time. In addition, fewer sites were under diversifying selection in the vaccine group than in the placebo group. These results indicate that HIV-1 would possibly adapt to a vaccine upon its roll-out. [ABSTRACT FROM AUTHOR]

While large datasets of HIV-1 sequences are increasingly being generated, many studies rely on a single gene or fragment of the genome and few comparative studies across genes have been done. We performed genome-based and gene-specific Bayesian phylogenetic analyses to investigate how certain factors impact estimates of the infection dates in an acute HIV-1 infection cohort, RV217. In this cohort, HIV-1 diagnosis corresponded to the first RNA positive test and occurred a median of four days after the last negative test, allowing us to compare timing estimates using BEAST to a narrow window of infection. We analyzed HIV-1 sequences sampled one week, one month and six months after HIV-1 diagnosis in 39 individuals. We found that shared diversity and temporal signal was limited in acute infection, and insufficient to allow timing inferences in the shortest HIV-1 genes, thus dated phylogenies were primarily analyzed for env, gag, pol and near full-length genomes. There was no one best fitting model across participants and genes, though relaxed molecular clocks (73% of best fitting models) and the Bayesian skyline (49%) tended to be favored. For infections with single founders, the infection date was estimated to be around one week pre-diagnosis for env (IQR: 3–9 days) and gag (IQR: 5–9 days), whilst the genome placed it at a median of 10 days (IQR: 4–19). Multiply-founded infections proved problematic to date. Our ability to compare timing inferences to precise estimates of HIV-1 infection (within a week) highlights that molecular dating methods can be applied to within-host datasets from early infection. Nonetheless, our results also suggest caution when using uniform clock and population models or short genes with limited information content. Author summary: Molecular dating using phylogenetics allows us to estimate the date of an infection from time-stamped within-host sequences alone. There are large datasets of HIV-1 sequences, but genome and gene analyses are not often performed in parallel and rarely with the possibility to compare results against a known narrow window of infection. We showed that all but the longest genes are near-clonal in acute infection, with little information for dating purposes. For infections with single founders, we estimated the eclipse phase—the time between HIV-1 exposure and the first positive diagnostic test—to last between one and two weeks using env, gag, pol and near full-length genomes. This approach could be used to narrow the date of suspected infection in ongoing clinical trials for the prevention of HIV-1 infection. [ABSTRACT FROM AUTHOR]

The RV144 vaccine efficacy clinical trial showed a reduction in HIV-1 infections by 31%. Vaccine efficacy was associated with stronger binding antibody responses to the HIV Envelope (Env) V1V2 region, with decreased efficacy as responses wane. High levels of Ab-dependent cellular cytotoxicity (ADCC) together with low plasma levels of Env-specific IgA also correlated with decreased infection risk. We investigated whether B cell priming from RV144 vaccination impacted functional antibody responses to HIV-1 following infection. Antibody responses were assessed in 37 vaccine and 63 placebo recipients at 6, 12, and 36 months following HIV diagnosis. The magnitude, specificity, dynamics, subclass recognition and distribution of the binding antibody response following infection were different in RV144 vaccine recipients compared to placebo recipients. Vaccine recipients demonstrated increased IgG1 binding specifically to V1V2, as well as increased IgG2 and IgG4 but decreased IgG3 to HIV-1 Env. No difference in IgA binding to HIV-1 Env was detected between the vaccine and placebo recipients following infection. RV144 vaccination limited the development of broadly neutralizing antibodies post-infection, but enhanced Fc-mediated effector functions indicating B cell priming by RV144 vaccination impacted downstream antibody function. However, these functional responses were not associated with clinical markers of disease progression. These data reveal that RV144 vaccination primed B cells towards specific binding and functional antibody responses following HIV-1 infection. Author summary: The RV144 vaccine efficacy trial showed a reduction in HIV-1 infections that associated with binding antibody responses to the Envelope (Env) V1V2 loops but precise mechanisms remain unclear. To evaluate the effect of vaccine priming, we performed a systems serology analysis in 37 vaccine and 63 placebo recipients 6, 12 and 36 months after HIV-1 breakthrough infections. Vaccinees were characterized by strong V1V2-specific antibody responses synergized with V1V2-specific ADCP responses, whereas placebo recipients had stronger IgG3 and gp120-specific responses. The strongest distinguishing feature for vaccinees was IgG4 responses. RV144 vaccination enhanced Fc-mediated effector functions but limited the development of broadly neutralizing antibodies post-infection, which were found in eight placebo recipients but no vaccinee. These data show that RV144 vaccination primed B cells towards specific binding and functional antibody responses, with differences between groups still manifest three years after infection, i.e. on average five years after vaccination. These long-term consequences highlight that imprinting certain functions (while deterring other responses) could offer benefits even for leaky vaccines. [ABSTRACT FROM AUTHOR]

We analyzed human immunodeficiency virus envelope diversity in 98 acute infections. The within-host genetic diversity, divergence from transmitted/founder (T/F) strain, and the observed frequency of multiple T/F infections increased with Fiebig stage. These data identify rapid viral dynamics during acute infection with implications for clinical trials conducted in this setting. [ABSTRACT FROM AUTHOR]

Most HIV-1 infected individuals do not know their infection dates. Precise infection timing is crucial information for studies that document transmission networks or drug levels at infection. To improve infection timing, we used the prospective RV217 cohort where the window when plasma viremia becomes detectable is narrow: the last negative visit occurred a median of four days before the first detectable HIV-1 viremia with an RNA test, referred below as diagnosis. We sequenced 1,280 HIV-1 genomes from 39 participants at a median of 4, 32 and 170 days post-diagnosis. HIV-1 infections were dated by using sequence-based methods and a viral load regression method. Bayesian coalescent and viral load regression estimated that infections occurred a median of 6 days prior to diagnosis (IQR: 9–3 and 11–4 days prior, respectively). Poisson-Fitter, which analyzes the distribution of hamming distances among sequences, estimated a median of 7 days prior to diagnosis (IQR: 15–4 days) based on sequences sampled 4 days post-diagnosis, but it did not yield plausible results using sequences sampled at 32 days. Fourteen participants reported a high-risk exposure event at a median of 8 days prior to diagnosis (IQR: 12 to 6 days prior). These different methods concurred that HIV-1 infection occurred about a week before detectable viremia, corresponding to 20 days (IQR: 34–15 days) before peak viral load. Together, our methods comparison helps define a framework for future dating studies in early HIV-1 infection. Author summary: HIV-1 infected individuals rarely know when they became infected but knowing when an infection occurred provides critical information regarding HIV-1 pathogenesis and epidemiology. Using a unique cohort in which infection was known to have occurred in a narrow interval, we investigated methods to estimate the timing of infections. Several methods suggested that HIV-1 infection typically occurs a median of one week before the infection can be detected by HIV-1 RNA testing. Going forward, we provide a strategy that can be used to elucidate the origin of an acute/early infection. [ABSTRACT FROM AUTHOR]

HIV-1 strain diversity in Bulgaria is extensive and includes contributions from nearly all major subtypes and the Circulating Recombinant Forms (CRF): 01_AE, 02_AG, and 05_DF. Prior to this study, HIV-1 sequence information from Bulgaria has been based solely on the pro-RT gene, which represent less than 15% of the viral genome. To further characterize HIV-1 in Bulgaria, assess participant risk behaviors, and strengthen knowledge of circulating strains in the region, the study “Genetic Subtypes of HIV-1 in Bulgaria (RV240)” was conducted. This study employed the real time-PCR based Multi-region Hybridization Assay (MHA) B/non-B and HIV-1 sequencing to survey 215 of the approximately 1100 known HIV-1 infected Bulgarian adults (2008–2009) and determine if they were infected with subtype B HIV-1. The results indicated a subtype B prevalence of 40% and demonstrate the application of the MHA B/non-B in an area containing broad HIV-1 strain diversity. Within the assessed risk behaviors, the proportion of subtype B infection was greatest in men who have sex with men and lowest among those with drug use risk factors. During this study, 15 near full-length genomes and 22 envelope sequences were isolated from study participants. Phylogenetic analysis shows the presence of subtypes A1, B, C, F1, and G, CRF01_AE, CRF02_AG, CRF05_DF, and one unique recombinant form (URF). These sequences also show the presence of two strain groups containing participants with similar risk factors. Previous studies in African and Asian cohorts have shown that co-circulation of multiple subtypes can lead to viral recombination within super-infected individuals and the emergence of new URFs. The low prevalence of URFs in the presence of high subtype diversity in this study, may be the result of successful infection prevention and control programs. Continued epidemiological monitoring and support of infection prevention programs will help maintain control of the HIV-1 epidemic in Bulgaria. [ABSTRACT FROM AUTHOR]

Although the HVTN 505 DNA/recombinant adenovirus type 5 vector HIV-1 vaccine trial showed no overall efficacy, analysis of breakthrough HIV-1 sequences in participants can help determine whether vaccine-induced immune responses impacted viruses that caused infection. We analyzed 480 HIV-1 genomes sampled from 27 vaccine and 20 placebo recipients and found that intra-host HIV-1 diversity was significantly lower in vaccine recipients (P ≤ 0.04, Q-values ≤ 0.09) in Gag, Pol, Vif and envelope glycoprotein gp120 (Env-gp120). Furthermore, Env-gp120 sequences from vaccine recipients were significantly more distant from the subtype B vaccine insert than sequences from placebo recipients (P = 0.01, Q-value = 0.12). These vaccine effects were associated with signatures mapping to CD4 binding site and CD4-induced monoclonal antibody footprints. These results suggest either (i) no vaccine efficacy to block acquisition of any viral genotype but vaccine-accelerated Env evolution post-acquisition; or (ii) vaccine efficacy against HIV-1s with Env sequences closest to the vaccine insert combined with increased acquisition due to other factors, potentially including the vaccine vector. [ABSTRACT FROM AUTHOR]

In order to inform the rational design of HIV-1 preventive and cure interventions it is critical to understand the events occurring during acute HIV-1 infection (AHI). Using viral deep sequencing on six participants from the early capture acute infection RV217 cohort, we have studied HIV-1 evolution in plasma collected twice weekly during the first weeks following the advent of viremia. The analysis of infections established by multiple transmitted/founder (T/F) viruses revealed novel viral profiles that included: a) the low-level persistence of minor T/F variants, b) the rapid replacement of the major T/F by a minor T/F, and c) an initial expansion of the minor T/F followed by a quick collapse of the same minor T/F to low frequency. In most participants, cytotoxic T-lymphocyte (CTL) escape was first detected at the end of peak viremia downslope, proceeded at higher rates than previously measured in HIV-1 infection, and usually occurred through the exploration of multiple mutational pathways within an epitope. The rapid emergence of CTL escape variants suggests a strong and early CTL response. Minor T/F viral strains can contribute to rapid and varied profiles of HIV-1 quasispecies evolution during AHI. Overall, our results demonstrate that early, deep, and frequent sampling is needed to investigate viral/host interaction during AHI, which could help identify prerequisites for prevention and cure of HIV-1 infection. [ABSTRACT FROM AUTHOR]

In preparation for vaccine trials, HIV-1 genetic diversity was surveyed between 2002 and 2006 through the Cohort Development study in the form of a retrospective and prospective observational study in and around the town of Mbeya in Tanzania's Southwest Highlands. This study describes the molecular epidemiology of HIV-1 strains obtained from 97 out of 106 incident HIV-1 infections identified in three subpopulations of participants (one rural, two urban) from the Mbeya area. Near full-genome or half-genome sequencing showed a subtype distribution of 40% C, 17% A1, 1% D, and 42% inter-subtype recombinants. Compared to viral subtyping results previously obtained from the retrospective phase of this study, the overall proportion of incident viral strains did not change greatly during the study course, suggesting maturity of the epidemic. A comparison to a current Phase I-II vaccine being tested in Africa shows ∼17% amino acid sequence difference between the gp120 of the vaccine and subtype C incident strains. Phylogenetic and recombinant breakpoint analysis of the incident strains revealed the emergence of CRF41_CD and many unique recombinants, as well as the presence of six local transmission networks most of which were confined to the rural subpopulation. In the context of vaccine cohort selection, these results suggest distinct infection transmission dynamics within these three geographically close subpopulations. The diversity and genetic sequences of the HIV-1 strains obtained during this study will greatly contribute to the planning, immunogen selection, and analysis of vaccine-induced immune responses observed during HIV-1 vaccine trials in Tanzania and neighboring countries. [ABSTRACT FROM AUTHOR]

Characterization of HIV-1 subtype diversity in regions where vaccine trials are conducted is critical for vaccine development and testing. This study describes the molecular epidemiology of HIV-1 within a tea-plantation community cohort in Kericho, Kenya. Sixty-three incident infections were ascertained in the HIV and Malaria Cohort Study conducted in Kericho from 2003 to 2006. HIV-1 strains from 58 of those individuals were full genome characterized and compared to two previous Kenyan studies describing 41 prevalent infections from a blood bank survey (1999–2000) and 21 infections from a higher-risk cohort containing a mix of incident and prevalent infections (2006). Among the 58 strains from the community cohort, 43.1% were pure subtypes (36.2% A1, 5.2% C, and 1.7% G) and 56.9% were inter-subtype recombinants (29.3% A1D, 8.6% A1CD, 6.9% A1A2D, 5.2% A1C, 3.4% A1A2CD, and 3.4% A2D). This diversity and the resulting genetic distance between the observed strains will need to be addressed when vaccine immunogens are chosen. In consideration of current vaccine development efforts, the strains from these three studies were compared to five candidate vaccines (each of which are viral vectored, carrying inserts corresponding to parts of gag, pol, and envelope), which have been developed for possible use in sub-Saharan Africa. The sequence comparison between the observed strains and the candidate vaccines indicates that in the presence of diverse recombinants, a bivalent vaccine is more likely to provide T-cell epitope coverage than monovalent vaccines even when the inserts of the bivalent vaccine are not subtype-matched to the local epidemic. [ABSTRACT FROM AUTHOR]

The RV144 clinical trial showed the partial efficacy of a vaccine regimen with an estimated vaccine efficacy (VE) of 31% for protecting low-risk Thai volunteers against acquisition of HIV-1. The impact of vaccine-induced immune responses can be investigated through sieve analysis of HIV-1 breakthrough infections (infected vaccine and placebo recipients). A V1/V2-targeted comparison of the genomes of HIV-1 breakthrough viruses identified two V2 amino acid sites that differed between the vaccine and placebo groups. Here we extended the V1/V2 analysis to the entire HIV-1 genome using an array of methods based on individual sites, k-mers and genes/proteins. We identified 56 amino acid sites or “signatures” and 119 k-mers that differed between the vaccine and placebo groups. Of those, 19 sites and 38 k-mers were located in the regions comprising the RV144 vaccine (Env-gp120, Gag, and Pro). The nine signature sites in Env-gp120 were significantly enriched for known antibody-associated sites (p = 0.0021). In particular, site 317 in the third variable loop (V3) overlapped with a hotspot of antibody recognition, and sites 369 and 424 were linked to CD4 binding site neutralization. The identified signature sites significantly covaried with other sites across the genome (mean = 32.1) more than did non-signature sites (mean = 0.9) (p < 0.0001), suggesting functional and/or structural relevance of the signature sites. Since signature sites were not preferentially restricted to the vaccine immunogens and because most of the associations were insignificant following correction for multiple testing, we predict that few of the genetic differences are strongly linked to the RV144 vaccine-induced immune pressure. In addition to presenting results of the first complete-genome analysis of the breakthrough infections in the RV144 trial, this work describes a set of statistical methods and tools applicable to analysis of breakthrough infection genomes in general vaccine efficacy trials for diverse pathogens. [ABSTRACT FROM AUTHOR]

The modest protection afforded by the RV144 vaccine offers an opportunity to evaluate its mechanisms of protection. Differences between HIV-1 breakthrough viruses from vaccine and placebo recipients can be attributed to the RV144 vaccine as this was a randomized and double-blinded trial. CD8 and CD4 T cell epitope repertoires were predicted in HIV-1 proteomes from 110 RV144 participants. Predicted Gag epitope repertoires were smaller in vaccine than in placebo recipients (p = 0.019). After comparing participant-derived epitopes to corresponding epitopes in the RV144 vaccine, the proportion of epitopes that could be matched differed depending on the protein conservation (only 36% of epitopes in Env vs 84–91% in Gag/Pol/Nef for CD8 predicted epitopes) or on vaccine insert subtype (55% against CRF01_AE vs 7% against subtype B). To compare predicted epitopes to the vaccine, we analyzed predicted binding affinity and evolutionary distance measurements. Comparisons between the vaccine and placebo arm did not reveal robust evidence for a T cell driven sieve effect, although some differences were noted in Env-V2 (0.022≤p-value≤0.231). The paucity of CD8 T cell responses identified following RV144 vaccination, with no evidence for V2 specificity, considered together both with the association of decreased infection risk in RV 144 participants with V-specific antibody responses and a V2 sieve effect, lead us to hypothesize that this sieve effect was not T cell specific. Overall, our results did not reveal a strong differential impact of vaccine-induced T cell responses among breakthrough infections in RV144 participants. [ABSTRACT FROM AUTHOR]

The advent of next generation sequencing technologies is providing new insight into HIV-1 diversity and evolution, which has created the need for bioinformatics tools that could be applied to the characterization of viral quasispecies. Here we present Nautilus, a bioinformatics package for the analysis of HIV-1 targeted deep sequencing data. The DeepHaplo module determines the nucleotide base frequency and read depth at each position and computes the haplotype frequencies based on the linkage among polymorphisms in the same next generation sequence read. The Motifs module computes the frequency of the variants in the setting of their sequence context and mapping orientation, which allows for the validation of polymorphisms and haplotypes when strand bias is suspected. Both modules are accessed through a user-friendly GUI, which runs on Mac OS X (version 10.7.4 or later), and are based on Python, JAVA, and R scripts. Nautilus is available from . [ABSTRACT FROM AUTHOR]

The U.S. military represents a unique population within the human immunodeficiency virus 1 (HIV-1) pandemic. The last comprehensive study of HIV-1 in members of the U.S. Navy and Marine Corps (Sea Services) was completed in 2000, before large-scale combat operations were taking place. Here, we present molecular characterization of HIV-1 from 40 Sea Services personnel who were identified during their seroconversion window and initially classified as HIV-1 negative during screening. Protease/reverse transcriptase ( pro/ rt) and envelope ( env) sequences were obtained from each member of the cohort. Phylogenetic analyses were carried out on these regions to determine relatedness within the cohort and calculate the most recent common ancestor for the related sequences. We identified 39 individuals infected with subtype B and one infected with CRF01_AE. Comparison of the pairwise genetic distance of Sea Service sequences and reference sequences in the env and pro/ rt regions showed that five samples were part of molecular clusters, a group of two and a group of three, confirmed by single genome amplification. Real-time molecular monitoring of new HIV-1 acquisitions in the Sea Services may have a role in facilitating public health interventions at sites where related HIV-1 infections are identified. [ABSTRACT FROM AUTHOR]