O estudo acompanha a rotina de um ensaio clínico de vacinas experimentais anti-HIV/AIDS desenvolvido no Projeto Praça Onze, da UFRJ, em colaboração com a rede mundial de pesquisas de vacinas anti-HIV/AIDS, HVTN (HIV Vaccine Trials Network) e apoio financeiro dos NIH (National Institutes of Health), dos EUA. Focaliza os processos de recrutamento, seleção e seguimento dos voluntários, articulando os aspectos mais gerais às particularidades e demandas locais deste estudo realizado no Rio de Janeiro, Brasil. Do ponto de vista teórico-conceitual utiliza recursos oriundos das ciências sociais - história, sociologia da ciência e da corrente interacionista da sociologia. O estudo mostra que, como todo ensaio clínico, o experimento do Projeto Praça Onze é uma atividade coletiva, sustentada sobre múltiplos atores e instâncias, com diversas racionalidades, o que gera uma permanente tensão. Estuda a tensão que se coloca, principalmente entre a expectativa dos profissionais envolvidos (aconselhadores, recrutadores, médicos, enfermeiros, farmacêuticos, gerentes e coordenadores de estudos) e a experiência vivenciada pelos voluntários, assim como as possíveis negociações propostas durante o desenvolvimento do protocolo, a partir do contexto sociopolítico onde o mesmo está inserido. Os profissionais, apesar de suas especificidades, articulam-se para incorporar do universo dos colegas suas linguagens e seus modos de agir, num processo de hibridização dos conhecimentos e práticas. Os voluntários do ensaio, por sua vez, submetem-se, por um lado a uma rotina de disciplina e compromisso, que implica na entrega de seu corpo à medicina, implícita nesse papel. Por outro, apropriam-se da lógica do ensaio clínico para, em sua ótica, transformar-se em um coadjuvante no descobrimento de uma nova biotecnologia, que neste caso, se coloca como uma questão de vida ou morte, para ele e para uma ampla comunidade de infectados pelo HIV. Para o voluntário a entrega do corpo à ciência faz parte da construção de uma bioidentidade e de uma biopolítica contemporânea, onde não se pode desconsiderar a constante inter-relação entre ciência, sociedade, técnica e política. / Study follows routine of a clinical trial on experimental anti-HIV/AIDS vaccines performed at the Praça Onze Project of UFRJ (Rio de Janeiro Federal University), in collaboration with the HIV Vaccine Trials Network and supported by NIHs (National Institutes of Health) in the USA. It focuses on the process of recruting, selecting and doing the follow-up of trial volunteers and on the articulation of more general aspects to local demands and particularities of a study when carried out in Rio de Janeiro, Brazil. From the theoreticalconceptual standpoint, it uses resources originated from Social Sciences such as History and Sociology of Science, as well as from the interactionist current of Sociology. Study shows how, as in any clinical trial, the Praça Onze Project experiment is a collective activity sustained by multiple actors and diverse rationales which give rise to tension. The study focus mostly the tension between professionals (counselors, recruters, physicians, nurses, study managers and coordinators) expectation and the experiences undergone by volunteers, as the negotiations occurred during the protocol development phase. Professionals, in spite of their specificities, articulate themselves so as to incorporate the vocabulary and behavior found in the universe shared with their peers, this being a process of knowledge and practice hybridization. From the volunteers standpoint, on one side, there is a submission to the discipline and commitment routine such process requires, offering their bodies to Medical Science. On the other side, there is an appropriation of the logic behind a clinical trial, with a self-perception of becoming someone playing a supporting role in the discovery of a new form of biotechnology; in this case, a life and death issue for them and for a collective of HIV infected people. For the volunteers, giving their bodies to science is part of the construction of a contemporary bioidentity and biopolitic, where science, society, technology and politics are interrelated.

O estudo acompanha a rotina de um ensaio clínico de vacinas experimentais anti-HIV/AIDS desenvolvido no Projeto Praça Onze, da UFRJ, em colaboração com a rede mundial de pesquisas de vacinas anti-HIV/AIDS, HVTN (HIV Vaccine Trials Network) e apoio financeiro dos NIH (National Institutes of Health), dos EUA. Focaliza os processos de recrutamento, seleção e seguimento dos voluntários, articulando os aspectos mais gerais às particularidades e demandas locais deste estudo realizado no Rio de Janeiro, Brasil. Do ponto de vista teórico-conceitual utiliza recursos oriundos das ciências sociais - história, sociologia da ciência e da corrente interacionista da sociologia. O estudo mostra que, como todo ensaio clínico, o experimento do Projeto Praça Onze é uma atividade coletiva, sustentada sobre múltiplos atores e instâncias, com diversas racionalidades, o que gera uma permanente tensão. Estuda a tensão que se coloca, principalmente entre a expectativa dos profissionais envolvidos (aconselhadores, recrutadores, médicos, enfermeiros, farmacêuticos, gerentes e coordenadores de estudos) e a experiência vivenciada pelos voluntários, assim como as possíveis negociações propostas durante o desenvolvimento do protocolo, a partir do contexto sociopolítico onde o mesmo está inserido. Os profissionais, apesar de suas especificidades, articulam-se para incorporar do universo dos colegas suas linguagens e seus modos de agir, num processo de hibridização dos conhecimentos e práticas. Os voluntários do ensaio, por sua vez, submetem-se, por um lado a uma rotina de disciplina e compromisso, que implica na entrega de seu corpo à medicina, implícita nesse papel. Por outro, apropriam-se da lógica do ensaio clínico para, em sua ótica, transformar-se em um coadjuvante no descobrimento de uma nova biotecnologia, que neste caso, se coloca como uma questão de vida ou morte, para ele e para uma ampla comunidade de infectados pelo HIV. Para o voluntário a entrega do corpo à ciência faz parte da construção de uma bioidentidade e de uma biopolítica contemporânea, onde não se pode desconsiderar a constante inter-relação entre ciência, sociedade, técnica e política. / Study follows routine of a clinical trial on experimental anti-HIV/AIDS vaccines performed at the Praça Onze Project of UFRJ (Rio de Janeiro Federal University), in collaboration with the HIV Vaccine Trials Network and supported by NIHs (National Institutes of Health) in the USA. It focuses on the process of recruting, selecting and doing the follow-up of trial volunteers and on the articulation of more general aspects to local demands and particularities of a study when carried out in Rio de Janeiro, Brazil. From the theoreticalconceptual standpoint, it uses resources originated from Social Sciences such as History and Sociology of Science, as well as from the interactionist current of Sociology. Study shows how, as in any clinical trial, the Praça Onze Project experiment is a collective activity sustained by multiple actors and diverse rationales which give rise to tension. The study focus mostly the tension between professionals (counselors, recruters, physicians, nurses, study managers and coordinators) expectation and the experiences undergone by volunteers, as the negotiations occurred during the protocol development phase. Professionals, in spite of their specificities, articulate themselves so as to incorporate the vocabulary and behavior found in the universe shared with their peers, this being a process of knowledge and practice hybridization. From the volunteers standpoint, on one side, there is a submission to the discipline and commitment routine such process requires, offering their bodies to Medical Science. On the other side, there is an appropriation of the logic behind a clinical trial, with a self-perception of becoming someone playing a supporting role in the discovery of a new form of biotechnology; in this case, a life and death issue for them and for a collective of HIV infected people. For the volunteers, giving their bodies to science is part of the construction of a contemporary bioidentity and biopolitic, where science, society, technology and politics are interrelated.

A pandemia de AIDS é um dos principais problemas de saúde pública no mundo e demanda o desenvolvimento de uma vacina eficaz. Uma abordagem vacinal ideal, baseada em resposta celular contra o HIV-1, deveria induzir uma resposta imune mediada tanto por células T CD4+ quanto CD8+. A diversidade genética do HIV-1 é uma grande preocupação para o desenvolvimento de uma vacina e sequências consenso têm sido utilizadas a fim de contornar a barreira imposta por essa diversidade. A escolha apropriada dos antígenos a comporem as construções vacinas também é relevante, visto que proteínas como Gag e Vif têm se mostrado bastante imunogênicas, enquanto alguns trabalhos têm demonstrado que Env possui características imunossupressoras e que respostas celulares contra esse antígeno podem ser danosas aos indivíduos vacinados. Nosso grupo demonstrou que uma vacina de DNA (HIVBr18) codificando 18 peptídeos para linfócitos T CD4+, promíscuos (capazes de se ligarem a múltiplas moléculas HLA-DR) e conservados na sequência consenso do subtipo B do HIV-1 foi capaz de induzir uma resposta celular ampla, polifuncional e de longa duração em camundongos BALB/c e transgênicos para moléculas HLA. Neste trabalho identificamos 34 peptídeos potencialmente reconhecidos por linfócitos T CD4+, promíscuos e conservados na sequência consenso dos consensos do grupo M do HIV-1. Uma vacina de DNA (HIVBr27) codificando 27 dos 34 peptídeos (exceto os 7 peptídeos de Env identificados) induziu uma resposta mais ampla e de maior magnitude que a vacina HIVBr18 em camundongos BALB/c. Além disso, a vacina HIVBr27 induziu maior frequência de linfócitos T CD4+ e CD8+ polifuncionais, capazes de proliferar e produzir as citocinas IFN-gama e TNF-alfa. Desenvolvemos também uma vacina de DNA (HIVenv7) codificando os 7 peptídeos de Env do HIV-1 identificados. A co-imunização de HIVenv7+HIVBr27 reduziu a amplitude da resposta celular contra peptídeos codificados pela vacina HIVBr27. Além disso, a co-imunização reduziu a magnitude da resposta e a frequência de linfócitos T CD4+ e CD8+ polifuncionais contra o pool de 27 peptídeos codificados por essa vacina. A vacina HIVBr27, desenhada para induzir uma resposta de linfócitos T CD4+ ampla e intensa contra peptídeos promíscuos e conservados da sequência consenso dos consensos do grupo M do HIV-1, é mais imunogênica e mais completa que a vacina HIVBr18, tendo potencial de conferir, em grande cobertura populacional, imunidade contra os diversos subtipos circulantes do vírus. O fenômeno observado na co-imunização com HIVenv7 sugere que a inclusão do envelope em imunógenos contra o HIV-1 possa ser prejudicial. Por outro lado, isto faz desse plasmídeo um alvo promissor para terapias imunológicas que visem indução de imunossupressão / The AIDS pandemic is a worldwide major public health problem and requires the development of an effective vaccine. An ideal vaccine approach based on cellular immune responses against HIV-1 should induce an immune response mediated by both CD4+ and CD8+ T cells. HIV-1 genetic diversity is a major concern for developing a vaccine and consensus sequences have been used to circumvent the barrier posed by this diversity. The appropriate choice of antigens to compose the vaccines is also relevant, since proteins such as Gag and Vif have been shown to be immunogenic, while some studies have shown that Env has immunosuppressive characteristics and cellular responses against this antigen can be harmful to vaccinated individuals. Our group has demonstrated that a DNA vaccine (HIVBr18) encoding promiscuous multiple HLA-DR binding, conserved B-subtype HIV-1 CD4+ T cell epitopes was able to induce a broad, polyfunctional and long lasting T cell response in BALB/c and HLA transgenic mice. In this work we identified 34 promiscuous and conserved sequences within the group M HIV-1 consensus of the consensus sequence, potentially recognized by CD4+ T cells. A DNA vaccine (HIVBr27) encoding 27 of the 34 peptides (except the 7 Env identified peptides) induced a broader and higher magnitude T cell response than HIVBr18 vaccine in BALB/c mice. Moreover, the vaccine HIVBr27 induced a higher frequency of polyfunctional CD4+ and CD8+ T cells, able to proliferate and produce the cytokines IFN-gama and TNF-alfa. We also developed a DNA vaccine (HIVenv7) encoding the 7 HIV-1 Env identified peptides. Co-immunization with HIVenv7+HIVBr27 reduced the breadth of the cellular immune response against the HIVBr27 encoded peptides. Besides, co-imunization reduced the magnitude of the response and the frequency of polyfunctional CD4+ and CD8+ T cells against the pool of 27 peptides encoded by this vaccine. The HIVBr27 vaccine, designed to induce a broad and intense CD4+ T cell response against promiscuous and conserved peptides within the group M HIV-1 consensus of the consensus sequence, is more immunogenic and more complete than the vaccine HIVBr18, having the potential to provide, with wide population coverage, immunity against various circulating subtypes of the virus. The phenomenon observed in the co-immunization with HIVenv7 suggests that the inclusion of the envelope in immunogens against HIV-1 may be harmful. On the other hand, these results suggest that HIVenv7 is a promising target for immune therapies aimed at inducing immunosuppression

Desde o início da pandemia de HIV/aids, a imunoterapia vem sendo utilizada como alternativa terapêutica numa tentativa de estimular uma resposta do sistema imunológico contra o agente agressor. Esta abordagem tem sido considerada promissora para obtenção do controle da infecção em longo prazo. A administração de células apresentadoras de antígeno, em especial células dendríticas, é fundamentada pelos conceitos de imunoterapia passiva e de terapia celular ativa (vacina terapêutica) além da perspectiva da eliminação dos chamados reservatórios virais, unindo assim estas diversas estratégias de intervenção. Dentre os diferentes antígenos do HIV utilizados para pulsar as células dendríticas, alguns dos melhores resultados foram obtidos com a inativação química do vírus, preservando a integridade da estrutura da sua superfície.Há alguns anos nosso grupo vem trabalhando com terapia celular baseada em células dendríticas derivadas de monócitos autólogos, pulsadas com HIV inativado quimicamente, seguindo o protocolo descrito por Lu e colaboradores em 2004. Aqui, nós apresentamos os resultados de um ensaio clínico de fase I/II que teve como objetivos avaliar a tolerância, segurança e impacto imunovirológico, de diferentes formulações do produto em pacientes cronicamente infectados pelo HIV, sem uso de antirretrovirais. Os participantes foram alocados em três braços para receber composições distintas: 3x107 células dendríticas sem pulso adicional de HIV inativado (Braço A), 3x106 células dendríticas com pulso adicional de HIV inativado (Braço B) ou 3x107 células dendríticas com pulso adicional de HIV inativado (Braço C). O número de participantes no braço A evoluiu com uma considerável diminuição ao longo do período de observação do estudo, prejudicando as avaliações. As análises dos outros braços mostraram que as preparações foram seguras, não se observando eventos adversos relacionados à intervenção. Os resultados sugeriram um aumento na carga viral plasmática associados a uma redução das sub-populações de linfócitos TCD4+ e TCD8+ nos pacientes do braço C além de uma redução na quantidade de linfócitos T reguladores nos indivíduos do braço B / Since the beginning of the HIV / aids pandemic, immunotherapy is being used as an alternative therapy in attempt to stimulate an immune response against the pathogenic agent. This approach has been considered as promising for achieving the control of infection in the long term. Administration of antigen presenting cells, particularly dendritic cells is based on the concepts of passive immunotherapy and active cellular therapy (therapeutic vaccine), with the perspective of eliminating the so-called viral reservoirs, thus joining different intervention strategies. From different antigens tested for loading DCs, some of the best results were obtained with chemically inactivated virus, which preserves its surface proteins.Our group has been working with cellular therapy based on dendritic cells derived from autologous monocytes pulsed with chemicallyinactivatedHIV, following the protocol described by Lu et al in 2004.Here, we present the results of a phase I / II clinical trial aimed to evaluate tolerance, safety and immunovirological impact of different product formulations in chronically HIV-infected individuals, naïve for antiretroviral treatment.Participants were allocated to receive: 3x107 un-pulsed DCs (Arm A), 3x106 HIV-pulsed DCs (Arm B) or 3x107 HIV-pulsed DCs (Arm C). The number of participants in the arm A evolved with a considerable decrease over the study, so any considerations about effect of DCs without antigen overload were difficult to carry out. Outcomes in other arms showedthat they were safe, with no adverse events related to the products. The results suggested an increase in plasma viral load and decline in CD4+ and CD8+ T cells subpopulations after intervention in arm C. Additionally, we observed a decrease in percentage of regulatory T cells in arm B patients

Thesis (MSc. (Physiology)) -- University of Limpopo, 2016 / Relevance: An increase in the number of HIV positive patients receiving HAART raises important concerns about the metabolic impact of these regimens. The treatment effectively reduces viral load and increase CD4+ count; unfortunately it seems to disrupt carbohydrate and lipid metabolic pathways thereby increasing the risk for CDL by placing an already chronically ill HIV population at risk of more chronic diseases. As a developing country, accessibility to safer regimens of HAART is limited thus patients exposed to toxicities from long term exposure to sub-optimal regimens are even at greater risk. The aim of this study was to assess the long term effects of HAART on biochemical parameters and body composition as an indication of carbohydrate and lipid metabolism. Methods: A prospective cohort of 87 patients receiving HAART for 12 months or more was conducted at baseline and follow-up. Venous blood was collected after an overnight fast. An automated enzymatic colorimetric test was used to analyse plasma glucose and serum TC, HDL-C and TG. The LDL-C levels were calculated from TC and HDL-C. Leptin levels were analysed using human leptin radioimmunoassay kit. Insulin was analysed using an automated access ultrasensitive insulin assay. Anthropometric measurements were taken for the determination of body fat distribution and BMI. All statistical analyses were performed using SPSS version 23. Results: Total cholesterol, LDL-C, and waist circumference significantly decreased from baseline to follow-up (p<0.05). Triglycerides and LDL-C levels were significantly affected by durations between 24–47 and 49–72 months respectively. There were no significant changes in the mean levels of leptin observed within the two lines of regime. Mean leptin levels were 11.36±8.52 ng/ml and 9.67±6.42 ng/ml at baseline and follow-up respectively. Furthermore, the duration of HAART significantly affected BMI and WC at 49–72 months. Patients that met the criteria for diagnosis of DM were only found in PI containing regimens at 6.3% and 5.9% baseline and follow-up respectively. In the first line regimen, the prevalence of DM was only found at follow-up. Conclusion: The present study demonstrated that longer duration between months 49–72 has significant negative effects on the glucose and lipid metabolism of HIV positive patients. The study also highlighted that patients on combinations containing PIs and NRTIs such as stavudine and zidovudine are at higher risk of developing metabolic diseases. / University of Limpopo

In 2008 the Nobel Prize in Physiology or Medicine was awarded to the co-discoverers of the Human Immunodeficiency Virus Type 1 (HIV-1), the causative agent of Acquired Immunodeficiency Syndrome (AIDS). This award acknowledged the enormous worldwide impact of the HIV-1/AIDS pandemic and the importance of research aimed at halting its spread. Since the syndrome was first recognized, 25 million people have succumbed to AIDS and over 33 million are currently infected with HIV-1 (www.unaids.org). The most effective strategy for ending the pandemic is the creation of a prophylactic vaccine. Yet, to date, all efforts at HIV-1 vaccine design have met with very limited success. The consistent failures of vaccine candidates stem in large part from the unprecedented diversity of HIV-1. Among the novel theories of vaccine design put forward to address this diversity is the targeted vaccine approach. This proposal is based on the finding that mucosal transmission of HIV-1, the most prevalent form, occurs across a selective bottleneck such that typically only a single (or a few) variants of the viral swarm present in a donor are passed to the recipient. While the mechanisms controlling the selection are largely unknown, the targeted vaccine approach postulates that once they are identified, we can utilize this understanding to design vaccines specifically targeted to the characteristics shared by the rare, mucosally transmissible HIV-1 variants. The studies described in this work were conducted to improve our understanding of the factors influencing viral variant selection during mother-to-child-transmission of HIV-1, a route of mucosal transmission which has globally become the leading cause of child infection. A unique panel was generated, consisting of nearly 300 HIV-1 envelope genes cloned from infected mother-infant pairs. Extensive characterization of the genotypes, phenotypes and phylogeny of these clones was then done to identify attributes differentiating early infant from maternal variants. Low genetic diversity of HIV-1 envelope variants was detected in early infant samples, suggesting a bottleneck and active selection of variants for transmission. Transmitted variants did not differ from non-transmitted variants in CD4 and CCR5 use. Infant isolates replicated poorly in macrophages; a cell subtype hypothesized to be important in the establishment of infection. The sensitivity of infant envelope variants to neutralization by a panel of monoclonal antibodies, heterologous and autologous plasmas and HIV-1 entry inhibitors varied. Most intriguingly, envelopes cloned from infants infected during delivery exhibited a faster entry phenotype than maternal isolates. Together, these findings provide further insight into viral variant selection during mother-to-child transmission. Identification of properties shared by mucosally transmitted viral variants may allow them to be selectively targeted, resulting in improved methods for preventing HIV-1 transmission.

Thesis (PhD)--Stellenbosch University, 2015 / ENGLISH ABSTRACT : In 2010, young people aged 15–24 years accounted for 42% of new HIV infections globally. In 2009, about five million (10%) of the total South African population was estimated to be aged 15–19 years. Current South African national sero-prevalence data estimate the prevalence of HIV to be 5.6% and 0.7% among adolescent girls and boys aged 15–19 years, respectively. HIV infections are mainly transmitted via sexual transmission. Adolescent sexuality is multi-faceted and influenced at multiple levels. In preparing to enroll adolescents in future biomedical HIV prevention trials, particularly prophylactic HIV vaccine trials, it is critical to provide counseling services appropriate to their needs. At the time of writing, there was no developed psychosocial intervention in South Africa for use among adolescent vaccine trial participants. Thus, the aim of the present study is to adapt and pilot-test a psychosocial intervention, namely, the Centers for Disease Control and Prevention (CDC) risk reduction counseling intervention of Project Respect, an intervention tasked at being developmentally and contextually appropriate among potential adolescent participants in HIV biomedical trials in the future. To achieve this overall aim, I qualitatively explored adolescent sexuality and risk factors for HIV among a diverse sample of participants aged 16–18 from Soweto. Thereafter, I developed a composite HIV risk scale in order to measure the variance in HIV risk among the sample of adolescents studied. The study followed a two-phased, mixed method research design and was informed by ecological systems theory and integrative model of behavioral prediction. The aim of Phase 1, split into phases 1a and b, was to conduct focus group discussions (FGDs) and to undertake a cross-sectional survey, respectively, to determine psychological (for example, self-esteem and depression), behavioral (specifically, sexual behavior) and social (specifically, social support, parent-adolescent communication) contexts that placed adolescents at risk for HIV infection. Phase 1a was qualitative, with data collected via nine FGDs: three involved parents of adolescents, four involved adolescents aged 16–18 years and two counselors. Nine key themes related to adolescent sexuality and risks for HIV acquisition were identified, namely: (1) dating during adolescence; (2) adolescent girls dating older men; (3) condom use amongst adolescents; (4) teenage pregnancies; (5) views about homosexuality; (6) parent-adolescent communication about sexual health; (7) the role of the media; (8) discipline and perceived government influence; and (9) group sex events. Phase 1b was quantitative and the data were collected via a cross-sectional survey to investigate the variance of risk for HIV. For Phase 1b, the sample consisted of 506 adolescents with a mean age of 17 years (interquartile range [IQR]: 16–18). More than half the participants were female (59%, n = 298). I used a three-step hierarchical multiple regression model to investigate the variance in risk for HIV. In step 3, the only significant predictors were “ever threatened to have sex” and “ever forced to have sex”, the combination of which explained 14% (R2 = 0.14; F (12, 236) = 3.14, p = 0.00). Depression and parentadolescent communication were added to steps 2 and 3, respectively, with both variables insignificant in these models. In Phase 2, I adapted and pilot tested the CDC risk reduction counseling intervention. The intervention was intended to be developmentally and contextually appropriate among adolescents from Soweto aged 16–18 years, viewed as potential participants in future HIV biomedical trials. Participants in Phase 2 were aged 16–18 years; the sample was mainly female (52%, n = 11) and most (91%, n = 19) were secondary school learners in grades 8 to 12. Participants provided feedback about their experiences of the adapted counseling intervention through in-depth interviews. I identified three main themes in this regard, namely: benefits of HIV testing services, reasons for seeking counseling and HIV testing services, and participants’ evaluation of the study visits and counseling sessions. The adapted CDC risk reduction counseling intervention was found to be acceptable with favorable outcomes for those adolescents who participated in the piloting phase. This study adds to the literature on risks for HIV among adolescents in Soweto, South Africa, by considering multiple levels of influence. Reaching a more complete understanding of ecological factors contributing to sexual risk behaviors among adolescents in the pilot-study enabled the development of a tailored counseling intervention. The findings showed the adapted CDC risk reduction counseling intervention to be feasible and acceptable among adolescents likely to be participants and eligible to participate in future HIV biomedical prevention trials. Thus, this study provides a much needed risk reduction counseling intervention that can be used among adolescents, an age group likely to participate in future HIV vaccine prevention research. / AFRIKAANSE OPSOMMING : In 2010 het jongmense tussen die ouderdomme van 15 en 24 jaar 42% van nuwe MIV-infeksies wêreldwyd uitgemaak. In 2009 was omtrent 5 miljoen mense (10%) van die Suid-Afrikaanse bevolking tussen 15 en 19 jaar oud. Volgens data oor die huidige Suid-Afrikaanse nasionale sero-voorkoms, word die voorkoms van MIV onderskeidelik op 5.6% en 0.7% onder tienermeisies en -seuns tussen die ouderdomme van 15 tot 19 jaar beraam. MIV-infeksies word hoofsaaklik deur seks oorgedra. Adolessente seksualiteit het baie fasette en word op verskeie vlakke beïnvloed. Ter voorbereiding van die werwing van adolessente vir toekomstige biomediese proewe, veral proewe oor profilaktiese MIVentstowwe, is dit van kritiese belang dat beradingsdienste verskaf word wat geskik is vir hul behoeftes. Op die tydstip wat hierdie tesis geskryf is, het daar nog geen psigososiale intervensie in Suid-Afrika bestaan vir gebruik onder adolessente deelnemers aan entstofproewe nie. Daarom is die doel van hierdie studie om ʼn psigososiale intervensie ‒ die Centers for Disease Control and Prevention (CDC) se Projek Respek, ʼn beradingsintervensie vir die vermindering van risiko ‒ aan te pas en met ʼn loodsprojek te toets. Hierdie intervensie is geskik vir die ontwikkelings- en kontekstuele vlak van adolessente deelnemers aan toekomstige MIV- biomediese proewe. Ten einde hierdie oorkoepelende doelwit te bereik, het ek adolessente seksualiteit en die risikofaktore vir MIV onder ʼn diverse steekproef deelnemers tussen die ouderdomme van 16 en 18 jaar van Soweto kwalitatief ondersoek. Daarna het ek ʼn saamgestelde MIV-risikoskaal ontwikkel om die variansie van MIV-risiko onder die groep adolessente te meet. Die studie se navorsingsontwerp het uit twee fases en gemengde metodes bestaan, en is gebaseer op ekologiesestelsel-teorie en die integrerende gedragsvoorspellingsmodel. Die doel van fase 1, wat in fases 1a en 1b verdeel is, was om onderskeidelik fokusgroepbesprekings te hou en om ʼn deursnitopname te doen om die sielkundige kontekste (byvoorbeeld elemente van selfbeeld en depressie), gedragskontekste (spesifiek seksuele gedrag) en sosiale kontekste (spesifiek sosiale ondersteuning en ouer-adolessent-kommunikasie) te bepaal waarin adolessente die risiko loop om MIV-infeksie op te doen. Fase 1a was kwalitatief en data is deur middel van nege fokusgroepbesprekings ingesamel: drie met die ouers van adolessente, vier met adolessente tussen 16 en 18 jaar oud en twee met beraders. Nege sleuteltemas is geïdentifiseer wat verband hou met adolessente seksualiteit en risiko’s om MIV op te doen: (1) verhoudings tydens adolessensie, (2) tienermeisies wat verhoudings met ouer mans het, (3) die gebruik van kondome onder adolessente, (4) tienerswangerskappe, (5) sienings oor homoseksualiteit, (6) ouer-adolessent-kommunikasie oor seksuele gesondheid, (7) die rol van die media, (8) dissipline en die ervaarde regeringsinvloed en (9) groepseksgeleenthede. Fase 1b was kwantitatief en data is deur middel van ’n deursnitopname ingesamel om die variansie van risiko vir MIV te ondersoek. Vir Fase 1b het die steekproef bestaan uit 506 adolessente met ’n gemiddelde ouderdom van 17 jaar (interkwartielwydte [IKW]: 16–18). Meer as die helfte van die deelnemers was vroulik (59%, n = 298). Ek het ’n hiërargiese meervoudige regressiemodel met drie stappe gebruik om die variansie van risiko vir MIV te ondersoek. Die enigste beduidende voorspellers in stap 3 was “ooit gedreig om seks te hê” en “ooit geforseer om seks te hê”. Die kombinasie hiervan het 14% (R2 = 0.14; F (12, 236) = 3.14, p = 0.00) verklaar. Depressie en oueradolessent- kommunikasie is onderskeidelik in stappe 2 en 3 bygevoeg, en albei veranderlikes was onbeduidend in hierdie modelle. In Fase 2 het ek die CDC se intervensie vir die verlaging van risiko aangepas en met ’n loodsprojek getoets. Die intervensie was bedoel om geskik te wees vir die ontwikkelings- en kontekstuele vlakke van 16- tot 18-jarige adolessente van Soweto wat beskou is as potensiële deelnemers aan toekomstige MIV- biomediese proewe. Deelnemers in Fase 2 was 16 tot 18 jaar oud, die steekproef was hoofsaaklik vroulik (52%, n = 11) en die meeste van die deelnemers (91%, n = 19) was in grade 8 tot 12 op hoërskool. Deelnemers het tydens indringende onderhoude terugvoering oor hulle ervarings van die aangepaste beradingsintervensie verskaf. Ek het drie hooftemas in hierdie verband geïdentifiseer, wat die volgende insluit: voordele van MIV-toetsingsdienste, redes waarom berading en MIV-toetsingsdienste verlang word, en die deelnemers se evaluering van die studiebesoeke en beradingsessies. Daar is bevind dat die aangepaste beradingsintervensie van die CDC aanvaarbaar was en gunstige uitkomste gelewer het vir die adolessente wat aan die loodsfase deelgeneem het. Hierdie studie dra by tot die literatuur oor MIV-risiko’s vir adolessente in Soweto, Suid-Afrika, deur meervoudige invloedsvlakke te oorweeg. Die feit dat ’n meer volledige begrip tydens die loodsondersoek verkry is van die interaksie van die ekologiese faktore wat tot seksuele risikogedrag onder adolessente bydra, het die ontwikkeling van ʼn doelgemaakte intervensie deur berading moontlik gemaak. Die bevindings het getoon dat die aangepaste beradingsintervensie van die CDC lewensvatbaar en aanvaarbaar is vir gebruik onder adolessente wat waarskynlik geskikte deelnemers aan toekomstige biomediese proewe oor MIV-voorkoming kan wees. Hierdie studie verskaf dus ʼn noodsaaklike beradingsintervensie om die MIV-risiko onder adolessente ‒ ʼn ouderdomsgroep wat waarskynlik aan toekomstige biomediese navorsing oor MIV-voorkoming sal deelneem ‒ te verminder.

In the history of public health vaccines have proven to be among the most effective disease prevention tools. It is clear that in the fight against HIV that new and powerful preventive technology such as a vaccine is badly needed. Ethically, however the processes of developing a vaccine against HIV have been distinctly different from that of any previous pharmaceutical products. HIV vaccine trials can be ethically complex for a number of reasons. In 2004 the HIV I AIDS Vaccine Ethics Group undertook a research initiative that aimed to collect data from various South African stake holders of HIV vaccine trials to ascertain what they perceived as the ethical challenges related to HIV vaccine trials. A quantitative content analysis on the data from 31 semistructured interviews revealed that the ethical issue listed spontaneously by most of the respondents was that of informed consent. Further probing and discussion on informed consent identified a number of sub issues which the respondents thought would pose important challenges to HIV vaccine trials in the South African context. This study undertook to do a more in-depth qualitative analysis of the data to ascertain whether the challenges and concerns the stakeholders have are consistent with or different to those already identified in the literature and ethical guidelines on informed consent in medical research. What variables may be impacting on the position stakeholders take was also of interest. Results indicated that many concerns relating to the substantive and procedural elements of informed consent were consistent with those debated in the literature. These issues related to first person consent, the voluntariness of participants' consent, practicing cultural sensitivity, dealing with language issues, promoting and assessing understanding of material disclosed, issues around the vulnerability of .. participants, children and adolescents' capacity to consent and the role of the media. More specific to the South African context, stakeholders were concerned about the legal framework under which the trials take place, the general lack of education and training about HIV vaccine trials, a lack of communication and coordination between stakeholder groups, and the historical influences of apartheid on black South African participants' capacity to consent. The main variables that appeared to impact on the position stakeholders took related to the role the stakeholders play within the trials, the philosophical position underpinning their ethical viewpoints, stakeholders' understanding of vulnerability and capacity to consent, and how they view the universality or relativity of ethical issues. / Thesis (M.A.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.

In recent years, heterologous prime-boost vaccination constructs have emerged as a promising strategy to generate broad and protective immunity against a variety of pathogens. The utility of DNA vaccination in priming the immune system, in particular, has improved the immunogenicity of vaccines against difficult pathogens such as HIV-1. In addition, many vaccine formulations include an adjuvant to augment immune responses. However, the mechanisms and profiles of many adjuvants remain largely unknown, particularly in the context of such combination immunization approaches. My thesis research studied the effects of several adjuvants, QS-21, aluminum hydroxide, MPL, and ISCOMATRIX™ adjuvant in the context of a previously described pentavalent HIV-1 Env DNA prime-protein boost vaccine, DP6-001. In a murine model, we quantified HIV antigen-specific humoral and T cell responses, as well as pro-inflammatory serum cytokine and chemokines, both shortly after immunization and at the termination of studies. Our data indicates that each candidate adjuvant generates a unique pattern of biomarkers as well as improved immunogenicity in the context of the DP6-001 DNA prime-protein boost vaccine. Additionally, we examined the impact of several innate signaling pathways on the adaptive immunity raised by DP6-001 and adjuvants, as well as on the unique serum cytokine profiles. These studies provide valuable information in selection of an adjuvant for inclusion in future prime-boost strategies, with the goal of enhancing immunogenicity while minimizing reactogenicity. Furthermore, these studies provided insight about the utility of different current adjuvants in a prime-boost formulation, and the unique immune environment induced by DNA priming.

The best known correlate of protection provided by vaccines is the presence of pathogen specific antibodies after immunization. However, against the Human Immunodeficiency Virus-1 (HIV-1) the mere presence of antibodies specific for the viral Envelope (Env) protein is not sufficient to provide protection. This necessitates in depth study of the humoral responses elicited during infection and by vaccination. While a significant amount of effort has been invested in studying the evolution of antibody responses to viral infection, only limited progress in understanding antibody responses elicited through vaccination has been made. In the studies described here, I attempt to rectify this deficiency by investigating how the quality of a humoral response is altered with the use of different immunization regimens, in particular a DNA prime-protein boost regimen, or with the use of different model HIV-1 Env gp120 immunogens. In a New Zealand White (NZW) rabbit model, we demonstrate that the broader neutralizing activity elicited with the DNA prime-protein boost regimen may be the result of the elicitation of a higher avidity antibody response and a unique profile of antibody specificities. Specifically, use of a DNA prime-protein boost regimen elicits antibodies targeted to the CD4 binding domain of the HIV-1 Env, a specificity that was not frequently observed when only protein based immunizations were administered. We extended this analysis to sera from healthy human volunteers who participated in early phase HIV vaccine trials utilizing either a protein alone immunization regimen, a canarypox prime-protein boost immunization regimen, or a DNA prime-protein boost immunization regimen. Evaluation of sera from these trials demonstrated that the use of a DNA prime-protein boost regimen results in an antibody response with greater neutralization breadth characterized by an increased frequency and titer of antibodies targeted toward the CD4 binding site (CD4bs). In addition to this, the antibody response elicited by the DNA prime-protein boost regimen also exhibited the capability to mediate antibody dependent cell-mediated cytotoxicity (ADCC) activity as well as activation of the complement system. Additionally, in an attempt to better understand the capabilities of antibodies elicited by a DNA prime-protein boost regimen, we generated gp120 specific monoclonal antibodies (mAbs) from a single DNA primed-protein boosted NZW rabbit. Analysis of mAbs produced from this animal revealed that use of this immunization regimen elicits an antibody repertoire with diverse epitope specificity and cross reactivity. Furthermore, these select mAbs are capable of neutralizing heterologous HIV isolates. Further application of mAb generation in rabbits may provide a valuable tool to study immunogenicity of different vaccines and immunization regimens. Concurrently, while demonstrating that a DNA prime-protein boost regimen elicits a higher quality antibody response than that observed with other leading techniques, we also demonstrated that immunogen selection can play a vital role in the quality of the resulting antibody response. By immunizing with two closely related but phenotypically distinct model gp120 immunogens, known as B33 and LN40, we demonstrated that disparate gp120s have different intrinsic abilities to raise a heterologous neutralizing antibody response. Additionally, we showed that residues found within and flanking the b12 and CD4 binding sites play critical roles in modulating neutralizing activity of sera from animals immunized with LN40 gp120, indicating that the broader neutralizing activity seen with this immunogen may be due to differential elicitation of antibodies to this domain.