HIV genotyping is a critical tool for antiviral drug resistance testing that has revolutionized HIV care and advanced HIVrelated research. Routine antiretroviral (ARV) drug resistance testing is useful in choosing an optimal treatment regimen and monitoring its efficiency in clinical practice (1-12). HIV genotyping has been used successfully in research on HIV transmission clusters and HIV transmission dynamics (13-35).Initial broadly used ARV regimens included combinations of nucleoside reverse transcriptase (RT) inhibitors (NRTIs) and nonnucleoside reverse transcriptase inhibitors (NNRTIs). To monitor the emergence of drug resistance mutations associated with NRTIs and NNRTIs, HIV genotyping targeted viral sequences spanning an approximately 1,000-to 1,300-bp region of the HIV-1 genome encoding viral protease and partial RT, using viral RNA as a template for amplification. While the RNA-based approach works well in antiretroviral therapy (ART)-naive individuals, it is less successful if levels of viral replication are low, such as in individuals on ART. The sequence length of traditional RNAbased HIV genotyping for drug resistance is relatively short and does not cover the HIV-1 region encoding viral integrase or the viral envelope, hindering analysis of drug resistance mutations associated with integrase strand transfer inhibitors or entry inhibitors. The global scale up of ARV treatment and successful introduction of integrase strand transfer inhibitors and entry inhibitors into clinical trials and clinical practice necessitate modification of traditional methods of HIV genotyping.Two commercial genotyping assays, ViroSeq HIV-1 from Abbott Molecular and TruGene HIV-1 from Siemens Molecular Diagnostics, have been widely used for analysis of HIV-1-associated drug resistance. Both genotyping kits were extensively tested and validated (36)(37)(38)(39)(40)(41)(42)(43)(44)(45). While the ViroSeq HIV-1 kit is still on the market, Siemens discontinued selling and supporting the TruGene HIV-1 kit in 2014. The ViroSeq HIV-1 kit covers the entire protease-coding region and the RT region encoding the first 320 amino acids. The TruGene HIV-1 sequences span the protease (amino acids 4 to 99)-and RT (amino acids 40 to 240)-coding regions. The CDC supplies WHO-designated and CDC-supported President's Emergency Plan for AIDS Relief (PEPFAR) Genotyping Laboratories with the ATCC HIV-1 Drug Resistance Genotyping kit (46) for drug resistance testing. Many experienced genotyping laboratories have developed their own in-house amplification and sequencing protocols (11,(47)(48)(49)(50)(51)(52)(53)(54)(55)(56), including identification of minor viral variants that are normally missed by commercial genotyping kits (57-61). All of these approaches generally include smaller and more restricted regions for testing HIV-1 drug resistance.Recently, the protocol developed by Gall et al. (62)

: Among 3596 HIV-positive participants enrolled in the Botswana Combination Prevention Project who self-reported no prior antiretroviral (ARV) therapy use and were tested for viral load (n = 951; 27% of all participants), 136 (14%) had HIV-1 RNA less than 400 copies/ml. ARV drugs were detected in 52 (39%) of 134 participants tested. Adjusting for undisclosed ARV use increased the overall estimate of virally suppressed individuals on ARV therapy by 1.4% from 70.2 to 71.6%.

Alcohol is the most widely abused substance in Namibia and is associated with poor adherence and retention in care among people on antiretroviral therapy (ART). Electronic screening and brief interventions (eSBI) are effective in reducing alcohol consumption in various contexts. We used a mixed methods approach to develop, implement, and evaluate the introduction of an eSBI in two ART clinics in Namibia. Of the 787 participants, 45% reported some alcohol use in the past 12 months and 25% reported hazardous drinking levels. Hazardous drinkers were more likely to be male, separated/widowed/divorced, have a monthly household income > $1000 NAD, and report less than excellent ART adherence. Based on qualitative feedback from participants and providers, ART patients using the eSBI for the first time found it to be a positive and beneficial experience. However, we identified several programmatic considerations that could improve the experience and yield in future implementation studies.

A critical global health need exists for a Zika vaccine capable of mitigating the effects of future Zika epidemics. In this study we evaluated the antibody responses and efficacy of an aluminum hydroxide adjuvanted purified inactivated Zika vaccine (PIZV) against challenge with Zika virus (ZIKV) strain PRVABC59. Indian rhesus macaques received two doses of PIZV at varying concentrations ranging from 0.016 µg − 10 µg and were subsequently challenged with ZIKV six weeks or one year following the second immunization. piZV induced a dose-dependent immune response that was boosted by a second immunization. Complete protection against ZIKV infection was achieved with the higher PIZV doses of 0.4 µg, 2 µg, and 10 µg at 6 weeks and with 10 ug PIZV at 1 year following vaccination. Partial protection was achieved with the lower PIZV doses of 0.016 µg and 0.08 µg. Based on these data, a neutralizing antibody response above 3.02 log 10 EC50 was determined as a correlate of protection in macaques. PIZV elicited a dose-dependent neutralizing antibody response which is protective for at least 1 year following vaccination.To further evaluate immunogenicity and efficacy of PIZV, we conducted three ZIKV challenge studies in rhesus macaques. In the first study, we established a dose of PRVABC59 challenge virus. In the second study, we determined the immunogenicity and efficacy of a wide range of PIZV dose levels at 42 days after two PIZV vaccinations, to establish a potential antibody correlate of protection. In the third study, we assessed the persistence of immunity and efficacy 1 year following administration of the second PIZV dose, to evaluate neutralizing antibody kinetics and long-term protection.

Background Phylogenetic mapping of HIV-1 lineages circulating across defined geographical locations is promising for better understanding HIV transmission networks to design optimal prevention interventions. Methods We obtained near full-length HIV-1 genome sequences from people living with HIV (PLWH), including participants on antiretroviral treatment in the Botswana Combination Prevention Project, conducted in 30 Botswana communities in 2013–2018. Phylogenetic relationships among viral sequences were estimated by maximum likelihood. Results We obtained 6078 near full-length HIV-1C genome sequences from 6075 PLWH. We identified 984 phylogenetically distinct HIV-1 lineages (molecular HIV clusters) circulating in Botswana by mid-2018, with 2–27 members per cluster. Of these, dyads accounted for 62%, approximately 32% (n = 316) were found in single communities, and 68% (n = 668) were spread across multiple communities. Men in clusters were approximately 3 years older than women (median age 42 years, vs 39 years; P < .0001). In 65% of clusters, men were older than women, while in 35% of clusters women were older than men. The majority of identified viral lineages were spread across multiple communities. Conclusions A large number of circulating phylogenetically distinct HIV-1C lineages (molecular HIV clusters) suggests highly diversified HIV transmission networks across Botswana communities by 2018.

Zika virus is a Flavivirus, transmitted via Aedes mosquitos, that causes a range of symptoms including Zika congenital syndrome. Zika has posed a challenging situation for health, public and economic sectors of affected countries. To quantitate Zika virus neutralizing antibody titers in serum samples, we developed a high throughput plate based Zika virus reporter virus particle (RVP) assay that uses an infective, non-replicating particle encoding Zika virus surface proteins and capsid (CprME) and a reporter gene (Renilla luciferase). This is the first characterization of a Zika virus RVP assay in 384-well format using a Dengue replicon Renilla reporter construct. Serially diluted test sera were incubated with RVPs, followed by incubation with Vero cells. RVPs that have not been neutralized by antibodies in the test sera entered the cells and expressed Renilla luciferase. Quantitative measurements of neutralizing activity were determined using a plate-based assay and commercially available substrate. The principle of limiting the infection to a single round increases the precision of the assay measurements. RVP log10EC50 titers correlated closely with titers determined using a plaque reduction neutralization test (PRNT) (R2>95%). The plate-based Zika virus RVP assay also demonstrated high levels of precision, reproducibility and throughput. The assay employs identical reagents for human, rhesus macaque and mouse serum matrices. Spiking studies indicated that the assay performs equally well in different species, producing comparable titers irrespective of the serum species. The assay is conducted in 384-well plates and can be automated to simultaneously achieve high throughput and high reproducibility.

An effective dengue vaccine should ideally induce broadly neutralizing antibody (nAb) responses against all four dengue virus (DENV) serotypes. We characterized the specificity and breadth of the nAb response to TAK-003, a live attenuated tetravalent dengue vaccine, in serum samples from phase 2 and 3 clinical trials. Microneutralization tests using post-vaccination serum showed comparable neutralization against diverse DENV-1−4 genotypes. Reporter virus particle neutralization assays post- depletion of anti-DENV-2 nAbs demonstrated that the nAb response to DENV-1, -3 and -4 comprises both type-specific (TS) and cross-reactive (CR) nAbs. Therefore, TAK-003 induces broad tetravalent TS and CR nAb responses.

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