Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 74
Filtrar
1.
Nat Immunol ; 24(7): 1161-1172, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37322179

RESUMO

Despite the success of COVID-19 vaccines, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern have emerged that can cause breakthrough infections. Although protection against severe disease has been largely preserved, the immunological mediators of protection in humans remain undefined. We performed a substudy on the ChAdOx1 nCoV-19 (AZD1222) vaccinees enrolled in a South African clinical trial. At peak immunogenicity, before infection, no differences were observed in immunoglobulin (Ig)G1-binding antibody titers; however, the vaccine induced different Fc-receptor-binding antibodies across groups. Vaccinees who resisted COVID-19 exclusively mounted FcγR3B-binding antibodies. In contrast, enhanced IgA and IgG3, linked to enriched FcγR2B binding, was observed in individuals who experienced breakthrough. Antibodies unable to bind to FcγR3B led to immune complex clearance and resulted in inflammatory cascades. Differential antibody binding to FcγR3B was linked to Fc-glycosylation differences in SARS-CoV-2-specific antibodies. These data potentially point to specific FcγR3B-mediated antibody functional profiles as critical markers of immunity against COVID-19.


Assuntos
COVID-19 , Vacinas , Humanos , ChAdOx1 nCoV-19 , Vacinas contra COVID-19/efeitos adversos , COVID-19/prevenção & controle , SARS-CoV-2 , Anticorpos Antivirais , Imunoglobulina G , Receptores Fc/genética , Anticorpos Neutralizantes , Vacinação
2.
N Engl J Med ; 384(20): 1899-1909, 2021 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-33951374

RESUMO

BACKGROUND: The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants threatens progress toward control of the coronavirus disease 2019 (Covid-19) pandemic. In a phase 1-2 trial involving healthy adults, the NVX-CoV2373 nanoparticle vaccine had an acceptable safety profile and was associated with strong neutralizing-antibody and antigen-specific polyfunctional CD4+ T-cell responses. Evaluation of vaccine efficacy was needed in a setting of ongoing SARS-CoV-2 transmission. METHODS: In this phase 2a-b trial in South Africa, we randomly assigned human immunodeficiency virus (HIV)-negative adults between the ages of 18 and 84 years or medically stable HIV-positive participants between the ages of 18 and 64 years in a 1:1 ratio to receive two doses of either the NVX-CoV2373 vaccine (5 µg of recombinant spike protein with 50 µg of Matrix-M1 adjuvant) or placebo. The primary end points were safety and vaccine efficacy against laboratory-confirmed symptomatic Covid-19 at 7 days or more after the second dose among participants without previous SARS-CoV-2 infection. RESULTS: Of 6324 participants who underwent screening, 4387 received at least one injection of vaccine or placebo. Approximately 30% of the participants were seropositive for SARS-CoV-2 at baseline. Among 2684 baseline seronegative participants (94% HIV-negative and 6% HIV-positive), predominantly mild-to-moderate Covid-19 developed in 15 participants in the vaccine group and in 29 in the placebo group (vaccine efficacy, 49.4%; 95% confidence interval [CI], 6.1 to 72.8). Vaccine efficacy among HIV-negative participants was 60.1% (95% CI, 19.9 to 80.1). Of 41 sequenced isolates, 38 (92.7%) were the B.1.351 variant. Post hoc vaccine efficacy against B.1.351 was 51.0% (95% CI, -0.6 to 76.2) among the HIV-negative participants. Preliminary local and systemic reactogenicity events were more common in the vaccine group; serious adverse events were rare in both groups. CONCLUSIONS: The NVX-CoV2373 vaccine was efficacious in preventing Covid-19, with higher vaccine efficacy observed among HIV-negative participants. Most infections were caused by the B.1.351 variant. (Funded by Novavax and the Bill and Melinda Gates Foundation; ClinicalTrials.gov number, NCT04533399.).


Assuntos
Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , Imunogenicidade da Vacina , SARS-CoV-2 , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Neutralizantes/sangue , COVID-19/epidemiologia , COVID-19/imunologia , COVID-19/virologia , Teste Sorológico para COVID-19 , Vacinas contra COVID-19/efeitos adversos , Método Duplo-Cego , Soronegatividade para HIV , Soropositividade para HIV , Humanos , Pessoa de Meia-Idade , SARS-CoV-2/isolamento & purificação , África do Sul , Adulto Jovem
3.
N Engl J Med ; 384(20): 1885-1898, 2021 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-33725432

RESUMO

BACKGROUND: Assessment of the safety and efficacy of vaccines against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in different populations is essential, as is investigation of the efficacy of the vaccines against emerging SARS-CoV-2 variants of concern, including the B.1.351 (501Y.V2) variant first identified in South Africa. METHODS: We conducted a multicenter, double-blind, randomized, controlled trial to assess the safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) in people not infected with the human immunodeficiency virus (HIV) in South Africa. Participants 18 to less than 65 years of age were assigned in a 1:1 ratio to receive two doses of vaccine containing 5×1010 viral particles or placebo (0.9% sodium chloride solution) 21 to 35 days apart. Serum samples obtained from 25 participants after the second dose were tested by pseudovirus and live-virus neutralization assays against the original D614G virus and the B.1.351 variant. The primary end points were safety and efficacy of the vaccine against laboratory-confirmed symptomatic coronavirus 2019 illness (Covid-19) more than 14 days after the second dose. RESULTS: Between June 24 and November 9, 2020, we enrolled 2026 HIV-negative adults (median age, 30 years); 1010 and 1011 participants received at least one dose of placebo or vaccine, respectively. Both the pseudovirus and the live-virus neutralization assays showed greater resistance to the B.1.351 variant in serum samples obtained from vaccine recipients than in samples from placebo recipients. In the primary end-point analysis, mild-to-moderate Covid-19 developed in 23 of 717 placebo recipients (3.2%) and in 19 of 750 vaccine recipients (2.5%), for an efficacy of 21.9% (95% confidence interval [CI], -49.9 to 59.8). Among the 42 participants with Covid-19, 39 cases (95.1% of 41 with sequencing data) were caused by the B.1.351 variant; vaccine efficacy against this variant, analyzed as a secondary end point, was 10.4% (95% CI, -76.8 to 54.8). The incidence of serious adverse events was balanced between the vaccine and placebo groups. CONCLUSIONS: A two-dose regimen of the ChAdOx1 nCoV-19 vaccine did not show protection against mild-to-moderate Covid-19 due to the B.1.351 variant. (Funded by the Bill and Melinda Gates Foundation and others; ClinicalTrials.gov number, NCT04444674; Pan African Clinical Trials Registry number, PACTR202006922165132).


Assuntos
Anticorpos Neutralizantes/sangue , Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , Imunogenicidade da Vacina , SARS-CoV-2 , Adenoviridae , Adolescente , Adulto , Anticorpos Neutralizantes/fisiologia , COVID-19/epidemiologia , COVID-19/imunologia , Teste Sorológico para COVID-19 , Vacinas contra COVID-19/administração & dosagem , Vacinas contra COVID-19/efeitos adversos , ChAdOx1 nCoV-19 , Método Duplo-Cego , Humanos , Pessoa de Meia-Idade , África do Sul , Linfócitos T/fisiologia , Falha de Tratamento , Potência de Vacina , Adulto Jovem
4.
AIDS Behav ; 28(6): 1999-2014, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38427124

RESUMO

HIV Pre-exposure Prophylaxis (PrEP) uptake among transgender (TG) people and gay men and other men who have sex with men (MSM) remains low, despite South Africa being the first African country to approve PrEP. This mixed-methods study used a two-phase explanatory sequential design: (1) quantitative analysis of cross-sectional surveys followed by (2) qualitative in-depth interviews. This study explored facilitators and barriers to PrEP uptake to identify strategies to increase utilization in these key populations. We conducted 202 cross-sectional surveys and 20 in-depth interviews between July 2021 and March 2022 in Soshanguve, Tshwane, Gauteng. Quantitative data were analyzed using univariate logistic regression; thematic analysis was performed for qualitative data. Findings show high willingness to use PrEP but low PrEP uptake. We outline strategies to facilitate PrEP use: (1) demystify daily PrEP by deploying community-engaged PrEP education campaigns; (2) capitalize on existing peer networks; and (3) expand accessible and culturally responsive PrEP service delivery models. We provide feasible recommendations to close the PrEP uptake gap in these key populations in South Africa.


Assuntos
Fármacos Anti-HIV , Infecções por HIV , Homossexualidade Masculina , Profilaxia Pré-Exposição , Pessoas Transgênero , Humanos , Masculino , África do Sul , Pessoas Transgênero/psicologia , Pessoas Transgênero/estatística & dados numéricos , Infecções por HIV/prevenção & controle , Estudos Transversais , Adulto , Homossexualidade Masculina/estatística & dados numéricos , Homossexualidade Masculina/psicologia , Fármacos Anti-HIV/uso terapêutico , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Pesquisa Qualitativa , Feminino , Adulto Jovem , Entrevistas como Assunto , Pessoa de Meia-Idade , Conhecimentos, Atitudes e Prática em Saúde , Minorias Sexuais e de Gênero/psicologia
5.
N Engl J Med ; 383(5): 426-439, 2020 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-32726529

RESUMO

BACKGROUND: Respiratory syncytial virus (RSV) is the dominant cause of severe lower respiratory tract infection in infants, with the most severe cases concentrated among younger infants. METHODS: Healthy pregnant women, at 28 weeks 0 days through 36 weeks 0 days of gestation, with an expected delivery date near the start of the RSV season, were randomly assigned in an overall ratio of approximately 2:1 to receive a single intramuscular dose of RSV fusion (F) protein nanoparticle vaccine or placebo. Infants were followed for 180 days to assess outcomes related to lower respiratory tract infection and for 364 days to assess safety. The primary end point was RSV-associated, medically significant lower respiratory tract infection up to 90 days of life, and the primary analysis of vaccine efficacy against the primary end point was performed in the per-protocol population of infants (prespecified criterion for success, lower bound of the 97.52% confidence interval [CI] of ≥30%). RESULTS: A total of 4636 women underwent randomization, and there were 4579 live births. During the first 90 days of life, the percentage of infants with RSV-associated, medically significant lower respiratory tract infection was 1.5% in the vaccine group and 2.4% in the placebo group (vaccine efficacy, 39.4%; 97.52% CI, -1.0 to 63.7; 95% CI, 5.3 to 61.2). The corresponding percentages for RSV-associated lower respiratory tract infection with severe hypoxemia were 0.5% and 1.0% (vaccine efficacy, 48.3%; 95% CI, -8.2 to 75.3), and the percentages for hospitalization for RSV-associated lower respiratory tract infection were 2.1% and 3.7% (vaccine efficacy, 44.4%; 95% CI, 19.6 to 61.5). Local injection-site reactions among the women were more common with vaccine than with placebo (40.7% vs. 9.9%), but the percentages of participants who had other adverse events were similar in the two groups. CONCLUSIONS: RSV F protein nanoparticle vaccination in pregnant women did not meet the prespecified success criterion for efficacy against RSV-associated, medically significant lower respiratory tract infection in infants up to 90 days of life. The suggestion of a possible benefit with respect to other end-point events involving RSV-associated respiratory disease in infants warrants further study. (Funded by Novavax and the Bill and Melinda Gates Foundation; ClinicalTrials.gov NCT02624947.).


Assuntos
Infecções por Vírus Respiratório Sincicial/prevenção & controle , Vacinas contra Vírus Sincicial Respiratório/imunologia , Vírus Sincicial Respiratório Humano , Infecções Respiratórias/prevenção & controle , Adolescente , Adulto , Ensaio de Imunoadsorção Enzimática , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Hipóxia/etiologia , Imunoglobulina G/sangue , Lactente , Recém-Nascido , Doenças do Recém-Nascido/prevenção & controle , Injeções Intramusculares , Nanopartículas , Distribuição de Poisson , Gravidez , Terceiro Trimestre da Gravidez , Infecções por Vírus Respiratório Sincicial/complicações , Infecções por Vírus Respiratório Sincicial/epidemiologia , Vírus Sincicial Respiratório Humano/imunologia , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/virologia , Vacinação , Proteínas Virais de Fusão/imunologia , Adulto Jovem
6.
AIDS Behav ; 27(12): 4124-4130, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37439915

RESUMO

Adolescent girls and young women (AGYW) account for 25% of new HIV infections in South Africa. Pre-exposure prophylaxis (PrEP) is approved by the South African Government, but the factors that promote PrEP uptake among AGYW are not well understood. This study examines multilevel factors associated with PrEP uptake among AGYW in six clinic catchment areas in Tshwane (Pretoria), South Africa. After consent/assent, PrEP-eligible AGYW (n = 448) completed a questionnaire assessing factors at the individual, network/interpersonal, and community levels and were prescribed PrEP in study clinics, if interested. A multivariable model, adjusting for clustering, assessed factors associated with PrEP uptake over a 9-month period. At the individual level, multiple partners in the past 3 months (OR = 0.47), perceived risk of HIV (OR = 0.71), and PrEP-related shame (OR = 0.63) were correlated with lower odds of PrEP uptake (ps ≤ 0.05). The findings highlight modifiable factors that should be addressed to support PrEP uptake efforts.


Assuntos
Fármacos Anti-HIV , Infecções por HIV , Profilaxia Pré-Exposição , Humanos , Feminino , Adolescente , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Infecções por HIV/tratamento farmacológico , África do Sul/epidemiologia , Fármacos Anti-HIV/uso terapêutico , Análise por Conglomerados
7.
BMC Womens Health ; 23(1): 58, 2023 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-36765358

RESUMO

BACKGROUND: Input from end-users during preclinical phases can support market fit for new HIV prevention technologies. With several long-acting pre-exposure prophylaxis (PrEP) implants in development, we aimed to understand young women's preferences for PrEP implants to inform optimal design. METHODS: We developed a discrete choice experiment and surveyed 800 young women in Harare, Zimbabwe and Tshwane, South Africa between September-November 2020. Women aged 18-30 years who were nulliparous, postpartum, or exchanged sex for money, goods or shelter in prior year were eligible; quotas were set for each subgroup. The DCE asked participants to choose between two hypothetical implants for HIV prevention in a series of nine questions. Implants were described by: size, number of rods and insertion sites, duration (6-months, 1-year, 2-years), flexibility, and biodegradability. Random-parameters logit models estimated preference weights. RESULTS: Median age was 24 years (interquartile range 21-27). By design, 36% had used contraceptive implants. Duration of protection was most important feature, with strong preference for a 2-year over 6-month implant. In Zimbabwe, the number of rods/insertion sites was second most important and half as important as duration. Nonetheless, to achieve an implant lasting 2-years, 74% were estimated to accept two rods, one in each arm. In South Africa, preference was for longer, flexible implants that required removal, although each of these attributes were one-third as important as duration. On average, biodegradability and size did not influence Zimbabwean women's choices. Contraceptive implant experience and parity did not influence relative importance of attributes. CONCLUSIONS: While duration of protection was a prominent attribute shaping women's choices for PrEP implants, other characteristics related to discreetness were relevant. Optimizing for longest dosing while also ensuring minimal detection of implant placement seemed most attractive to potential users.


Assuntos
Infecções por HIV , Gravidez , Humanos , Feminino , Adulto Jovem , Adulto , Infecções por HIV/prevenção & controle , Zimbábue , África do Sul , Inquéritos e Questionários , Anticoncepcionais
8.
AIDS Care ; 34(4): 478-485, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34180277

RESUMO

Current guidelines recommend starting antiretroviral therapy (ART) as soon as possible after HIV diagnosis to reduce morbidity, mortality and onward HIV transmission. We examined factors influencing ART initiation by women who seroconverted during the Evidence for Contraceptive Options and HIV Outcomes (ECHO) Trial. ECHO, conducted between 2015 and 2018, enrolled HIV-negative, sexually active women, aged 16-35 years, from four African countries. Follow-up was 12-18 months, with quarterly HIV testing. Women with incident HIV infection received extensive counselling by trial staff and referral to local facilities for HIV care. Of 304 women with ≥90 days follow-up time since HIV diagnosis, 186(61.2%) initiated ART within 90 days, 69(22.7%) initiated after 90 days, and 49(16.1%) had not initiated by the end of the study. There were no statistically significant differences in characteristics among women who initiated ART ≤90 days versus those who did not. Frequent reasons for delayed or non-initiation of ART included not feeling ready to start ART and being newly diagnosed. In a large clinical trial, ART initiation was modest within 90 days of HIV diagnosis and grew to 84% with longer observation. Despite extensive counselling on the importance of early ART initiation, personal barriers delayed some women from starting ART.


Assuntos
Fármacos Anti-HIV , Infecções por HIV , Adolescente , Adulto , África Subsaariana , Fármacos Anti-HIV/uso terapêutico , Anticoncepcionais/uso terapêutico , Aconselhamento , Feminino , Infecções por HIV/diagnóstico , Infecções por HIV/tratamento farmacológico , Humanos , Adulto Jovem
9.
Clin Trials ; 19(1): 81-85, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34875906

RESUMO

BACKGROUND: Ensuring protocol visit compliance and maintaining high participant retention remain critical elements of clinical trials. In the HVTN 702 HIV vaccine trial, Setshaba Research Centre in Soshanguve, Tshwane, South Africa, experienced challenges in communicating with participants to remind them about their study visits. In order to improve participants adhering to their study visits, and study retention, we aimed to identify challenges in mobile communication, and to establish preferences in communication methods and interest in receiving study information via cellphones. METHODS: We conducted a paper-based survey among HVTN 702 HIV vaccine trial participants at Setshaba Research Centre. The survey comprised of dichotomous and scale questions and was completed voluntarily and anonymously. The questions included those on their primary form of communication (calling, SMS and WhatsApp), the best time of day for the site to communicate with them, whether they were interested in receiving regular general study information updates via their cellular phone, how often they changed their cellular phones and/or network, whether they experienced any challenges with their cellular phones and what these challenges were, if any. All participants scheduled to visit the clinic from February to May 2019 were invited to participate. Thus, 90 of 380 (24%) participants enrolled by May 2019 were surveyed. RESULTS: The majority (68%) of participants were 26-35 years old and almost three-quarters (73%) were female. Almost all participants (99%) had a personal cellphone. Half of the participants experienced some challenge related to cellphones, these being poor network signal at home (12%), battery running flat frequently (11%), sharing their phone (9%), lack of data (9%), challenges with use of applications (6%) and their cellphones being unreliable (3%). Annually, 20% of participants made a single or multiple network changes. Communication preferences were calls by site staff (80%), SMS (16%) and WhatsApp (3%). Most preferred to be contacted in the morning (49%) or afternoon (31%). Site contact was rated as 'very helpful' (87%), and 97% were interested in receiving regular general study information updates via their cellphone. CONCLUSION: Despite participants owning cellphones, there are still technical challenges, for example, network signals, battery-charging and applications. The majority of participants preferred being called rather than communicating by text messages or WhatsApp. Future studies need to include addressing participant challenges in maintaining contact and training of participants on use of cellphone applications to optimise communication. Noting the preferred time of day for participants to be called might improve the likelihood of making contact with them. The willingness to receive updates will aid in keeping participant interest high and enhance retention.


Assuntos
Ensaios Clínicos como Assunto , Comunicação , Vacinas contra a AIDS , Adulto , Telefone Celular , Feminino , Humanos , Masculino , Telefone , Envio de Mensagens de Texto
10.
BMC Public Health ; 22(1): 1916, 2022 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-36242000

RESUMO

BACKGROUND: Globally, an urgent need exists to expand access to HIV prevention among adolescent girls and young women (AGYW), but the need is particularly acute in sub-Saharan Africa. Oral pre-exposure prophylaxis (PrEP) offers an effective HIV prevention method. In many countries, however, accessing PrEP necessitates that AGYW visit their local health clinic, where they may face access challenges. Some countries have implemented youth-friendly services to reduce certain challenges in local health clinics, but barriers to access persist, including clinic stigma. However, evidence of clinic stigma toward AGYW, particularly with respect to PrEP service delivery, is still limited. This mixed methods study explores stigma toward AGYW seeking clinic services, in particular PrEP, from the perspective of both clinic staff (clinical and nonclinical) and AGYW who seek services at clinic sites in Tshwane province, South Africa. METHODS: Six focus group discussions were conducted with AGYW (43 total participants) and four with clinic staff (42 total participants) and triangulated with survey data with AGYW (n = 449) and clinic staff (n = 130). Thematic analysis was applied to the qualitative data and descriptive statistics were conducted with the survey data. RESULTS: Four common themes emerged across the qualitative and quantitative data and with both AGYW and clinic staff, although with varying degrees of resonance between these two groups. These themes included (1) clinic manifestations of stigma toward AGYW, (2) concerns about providing PrEP services for AGYW, (3) healthcare providers' identity as mothers, and (4) privacy and breaches of confidentiality. An additional theme identified mainly in the AGYW data pertained to stigma and access to healthcare. CONCLUSION: Evidence is needed to inform strategies for addressing clinic stigma toward AGYW, with the goal of removing barriers to PrEP services for this group. While awareness has increased and progress has been achieved around the provision of comprehensive, youth-friendly sexual and reproductive health services, these programs need to be adapted for the specific concerns of young people seeking PrEP services. Our findings point to the four key areas noted above where programs seeking to address stigma toward AGYW in clinics can tailor their programming.


Assuntos
Fármacos Anti-HIV , Infecções por HIV , Profilaxia Pré-Exposição , Adolescente , Fármacos Anti-HIV/uso terapêutico , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/prevenção & controle , Humanos , Estigma Social , África do Sul
11.
Sex Transm Infect ; 97(4): 249-255, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33208512

RESUMO

OBJECTIVES: Reproductive aged women are at risk of pregnancy and sexually transmitted infections (STI). Understanding drivers of STI acquisition, including any association with widely used contraceptives, could help us to reduce STI prevalence and comorbidities. We compared the risk of STI among women randomised to three contraceptive methods. METHODS: We conducted a secondary analysis to assess the risk of chlamydia and gonorrhoea in a clinical trial evaluating HIV risk among 7829 women aged 16-35 randomised to intramuscular depot medroxyprogesterone acetate (DMPA-IM), a copper intrauterine device (IUD) or a levonorgestrel (LNG) implant. We estimated chlamydia and gonorrhoea prevalences by contraceptive group and prevalence ratios (PR) using log-binomial regression. RESULTS: At baseline, chlamydia and gonorrhoea prevalences were 18% and 5%, respectively. Final visit chlamydia prevalence did not differ significantly between DMPA-IM and copper IUD groups or between copper IUD and LNG implant groups. The DMPA-IM group had significantly lower risk of chlamydia compared with the LNG implant group (PR 0.83, 95% CI 0.72 to 0.95). Final visit gonorrhoea prevalence differed significantly only between the DMPA-IM and the copper IUD groups (PR 0.67, 95% CI 0.52 to 0.87). CONCLUSIONS: The findings suggest that chlamydia and gonorrhoea risk may vary with contraceptive method use. Further investigation is warranted to better understand the mechanisms of chlamydia and gonorrhoea susceptibility in the context of contraceptive use.


Assuntos
Infecções por Chlamydia/epidemiologia , Anticoncepção/métodos , Anticoncepcionais Femininos/administração & dosagem , Gonorreia/epidemiologia , Dispositivos Intrauterinos de Cobre , Levanogestrel/administração & dosagem , Acetato de Medroxiprogesterona/administração & dosagem , Adolescente , Adulto , África/epidemiologia , Preparações de Ação Retardada , Suscetibilidade a Doenças , Implantes de Medicamento , Feminino , Humanos , Prevalência , Adulto Jovem
12.
BMC Public Health ; 20(1): 1403, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32933510

RESUMO

BACKGROUND: Despite increased prevention efforts, HIV remains the leading cause of death among adolescent girls and young women in South Africa. Although research indicates important determinants of HIV acquisition at the individual and interpersonal levels, structural-level stigma and discrimination continue to be critical barriers to reaching and retaining this key population for HIV prevention and sexual and reproductive health services. Innovative and multilevel interventions are needed that can address the intersectional structural and gender issues that young women face, including stigma, alcohol and drug use, gender-based violence, and other risk factors when seeking health services. Oral pre-exposure prophylaxis (PrEP) taken daily has been found to be an effective biomedical HIV prevention tool. Testing a comprehensive gender-focused biobehavioral HIV prevention intervention that is inclusive of social ecological determinants, such as stigma and discrimination reduction in clinics, is critical for reducing HIV among adolescent girls and young women. METHODS: This project involves both a Community Collaborative Board and a Youth Advisory Board in helping to adapt the Young Women's Health CoOp intervention and the Health Policy Project (HPP) Stigma and Discrimination (S&D) reduction training curriculum to the setting and population. This study uses a two-by-two factorial design with stratified randomization of 12 clinics, each with distinct catchment areas. The Young Women's Health CoOp addresses substance use, sexual risk, violence prevention and sexual negotiation, condom demonstration, and problem solving with the following additions: knowledge of PrEP, the importance of PrEP adherence, and sexual and reproductive health. Adolescent girls and young women will be assessed with behavioral and biological measures at baseline, 3-, 6- and 9-month follow-up. The S&D reduction training is provided for all staff in the clinics randomized to this condition. Clinic staff will be surveyed at baseline, 4- and 8-month follow-up. We will recruit 900 AGYW from communities in the 12 clinic catchment areas. DISCUSSION: The study findings, if efficacious across the outcomes, will be incorporated into the gender-focused HIV prevention intervention toolkit and disseminated to inform multilevel prevention approaches. TRIAL REGISTRATION: ClinicalTrials.gov. Identifier: NCT04048551 (Recruiting). Registered: August 7, 2019 (Retrospectively registered).


Assuntos
Infecções por HIV , Preparações Farmacêuticas , Profilaxia Pré-Exposição , Adolescente , Feminino , Infecções por HIV/prevenção & controle , Humanos , Comportamento Sexual , África do Sul
13.
Sex Transm Infect ; 95(1): 5-12, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30018088

RESUMO

OBJECTIVES: Vaginal dysbiosis and STIs are important drivers of the HIV epidemic and reproductive complications. These conditions remain prevalent, partly because most cases are asymptomatic. We have shown that inflammatory cytokines interleukin (IL)-1α, IL-1ß and interferon-γ-induced protein (IP)-10 are biomarkers for detecting asymptomatic STIs and vaginal dysbiosis (bacterial vaginosis (BV) or intermediate microbiota). This study aimed to validate the performance of these biomarkers in African women recruited regardless of symptoms. METHODS: IL-1α, IL-1ß and IP-10 were measured in menstrual cup secretions, endocervical, lateral vaginal wall and vulvovaginal swabs from 550 women from Pretoria, Soweto and Cape Town, South Africa and Bondo, Kenya using Luminex and ELISA. STIs were assessed by PCR, BV by Nugent scoring and vaginal microbiota by 16S rRNA sequencing. RESULTS: Across four study populations and four types of genital specimens, the performance of IL-1α, IL-1ß and IP-10 for identification of women with STIs, BV or intermediate microbiota was consistent. Of the genital samples assessed, biomarkers measured in lateral vaginal wall swabs performed best, correctly classifying 76%(95% CI 70% to 81%) of women according to STI, BV or intermediate microbiota status (sensitivity 77%, specificity 71%) and were more accurate than clinical symptoms (sensitivity 41%, specificity 57%) (p=0.0003). Women incorrectly classified as STI/BV positive using the biomarkers had more abundant dysbiosis-associated bacteria, including Prevotella bivia and Gardnerella sp, detected by 16S rRNA sequencing, but not Nugent scoring. Including vaginal pH with the cytokine biomarkers improved the accuracy of the test (82% (95% CI 75% to 88%) correctly classified), although pH alone had poor specificity (61%). CONCLUSIONS: An inexpensive, point-of-care screening test including IL-1α, IL-1ß and IP-10 (and potentially pH) could be used in resource-limited settings to identify women with asymptomatic STIs and dysbiosis. These women could then be referred for aetiological testing, followed by specific treatment.


Assuntos
Infecções Assintomáticas , Quimiocina CXCL10/imunologia , Disbiose/imunologia , Interleucina-1alfa/imunologia , Interleucina-1beta/imunologia , Infecções Sexualmente Transmissíveis/imunologia , Vagina/imunologia , Vaginose Bacteriana/imunologia , Adolescente , Adulto , Doenças Assintomáticas , Biomarcadores , Secreções Corporais/química , Quimiocina CXCL10/metabolismo , Citocinas/imunologia , Citocinas/metabolismo , Disbiose/diagnóstico , Disbiose/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Gardnerella/genética , Humanos , Concentração de Íons de Hidrogênio , Inflamação , Interleucina-1alfa/metabolismo , Interleucina-1beta/metabolismo , Quênia , Programas de Rastreamento , Sistemas Automatizados de Assistência Junto ao Leito , Reação em Cadeia da Polimerase , Prevotella/genética , RNA Ribossômico 16S/análise , Infecções Sexualmente Transmissíveis/diagnóstico , Infecções Sexualmente Transmissíveis/metabolismo , África do Sul , Vagina/química , Vagina/metabolismo , Vagina/microbiologia , Vaginose Bacteriana/diagnóstico , Vaginose Bacteriana/metabolismo , Adulto Jovem
14.
AIDS Behav ; 22(8): 2662-2673, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29560570

RESUMO

End-user input is critical to inform development of multipurpose prevention technology (MPT) products that prevent HIV and pregnancy. The TRIO Study, conducted in Kenya and South Africa, enrolled 277 HIV-negative women aged 18-30 in a randomized cross-over study to use each placebo MPT (daily oral tablets, monthly injections, and monthly vaginal ring) for one month. At the end of each month, participants rated how much they liked using the product on a 5-point Likert scale (5 = liked very much). We compared mean ratings using paired t-tests and examined sociodemographic-, attribute-, and behavior-related characteristics associated with ratings using multivariable linear regression and data from in-depth interviews. After use, mean ratings were significantly higher for injections [4.3 (SD = 1.0)] compared with tablets [3.0 (SD = 1.3)] and rings [3.3 (SD = 1.4)] (p < 0.001); mean ratings for rings were significantly higher than for tablets (p = 0.013). Mean ratings of a hypothetical active MPT increased for all products after the one-month period of use, with the greatest increase for rings, the least familiar product. In multivariable analysis, acceptability of key product attributes (e.g., product look) were associated with a significant increase of ≥ 1 point in the mean rating across all three products (p ≤ 0.001). Perceived ability to use the product without partner knowledge was associated with a higher mean rating for rings (b = 0.50; p = 0.006). The acceptability of product attributes contributed significantly to the rating of all products, highlighting the value of choice in pregnancy and HIV prevention to accommodate diverse users.


Assuntos
Administração Oral , Anticoncepção/métodos , Anticoncepcionais/administração & dosagem , Dispositivos Anticoncepcionais Femininos , Infecções por HIV/prevenção & controle , Injeções , Profilaxia Pré-Exposição/métodos , Adolescente , Adulto , Estudos Cross-Over , Feminino , Humanos , Quênia , Modelos Lineares , Análise Multivariada , Aceitação pelo Paciente de Cuidados de Saúde , Satisfação do Paciente , Placebos , Parceiros Sexuais , África do Sul , Adulto Jovem
15.
AIDS Behav ; 22(1): 133-145, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29052018

RESUMO

A multipurpose prevention technology (MPT) that combines HIV and pregnancy prevention is a promising women's health intervention, particularly for young women. However, little is known about the drivers of acceptability and product choice for MPTs in this population. This paper explores approval ratings and stated choice across three different MPT delivery forms among potential end-users. The Trio Study was a mixed-methods study in women ages 18-30 that examined acceptability of three MPT delivery forms: oral tablets, injections, and vaginal ring. Approval ratings and stated choice among the products was collected at baseline. Factors influencing stated product choice were explored using multivariable multinomial logistic regression. The majority (62%) of women in Trio stated they would choose injections, 27% would choose tablets and 11% would choose the ring. Significant predictors of choice included past experience with similar contraceptive delivery forms, age, and citing frequency of use as important. Ring choice was higher for older (25-30) women than for younger (18-24) women (aRR = 3.1; p < 0.05). These results highlight the importance of familiarity in MPT product choice of potential for variations in MPT preference by age.


Assuntos
Fármacos Anti-HIV/administração & dosagem , Comportamento de Escolha , Controle de Doenças Transmissíveis/métodos , Anticoncepção/métodos , Infecções por HIV/prevenção & controle , Infecções por HIV/psicologia , Administração Intravaginal , Administração Intravenosa , Administração Oral , Adolescente , Adulto , Comportamento do Consumidor , Anticoncepção/psicologia , Feminino , Humanos , Quênia , Gravidez , África do Sul , Saúde da Mulher , Adulto Jovem
17.
AIDS Behav ; 20(11): 2565-2577, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-26204987

RESUMO

A randomized, placebo-controlled, efficacy trial of Carraguard was unable to demonstrate a reduction in women's risk of HIV infection, which may have been due, in part, to low adherence (gel used in 42 % of vaginal sex acts, on average). A secondary analysis was undertaken to understand baseline factors associated with high adherence (gel used in ≥85 % of sex acts). Women who reported ≥1 vaginal sex act, returned ≥1 opened applicator, and had ≥1 conclusive post-enrollment HIV test (N = 5990) were included. Adherence was estimated as the ratio of average weekly applicator insertions (based on a dye stain assay indicating vaginal insertion)/average weekly sex acts (by self-report). Multivariate logistic regression modeling indicated that coital frequency, site, contraception, and partner age difference had a significant impact on adherence. Women reporting >1 and ≤2 vaginal sex acts per week, on average, were half as likely to be adherent as those reporting 1 vaginal sex act per week or less [adjusted odds ratio (AOR): 0.48; 95 % CI 0.38-0.61]; women from the Western Cape had one-third the odds of being adherent compared to women from KZN (AOR: 0.31; 95 % CI 0.23-0.41); compared to women using injectable contraception, women using any other or no method were more likely to be adherent (AOR: 1.30; 95 % CI 1.04-1.63); and women who had a larger age gap from their partners were more likely to be adherent (AOR: 1.03; 95 % CI 1.01-1.05; p = 0.001). Despite low adherence, overall, 13 % of participants achieved nearly perfect adherence, indicating a potential niche for a coitally dependent microbicide. More research is needed on the impact of sexual patterns and HIV risk perception on product acceptability and adherence to improve counseling in ongoing trials and when products are eventually introduced.


Assuntos
Anti-Infecciosos/administração & dosagem , Infecções por HIV/prevenção & controle , Adesão à Medicação , Comportamento Sexual , Cremes, Espumas e Géis Vaginais/administração & dosagem , Adolescente , Adulto , Anti-Infecciosos/efeitos adversos , Coito , Feminino , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Humanos , Incidência , Modelos Logísticos , Pessoa de Meia-Idade , Análise Multivariada , África do Sul/epidemiologia , Cremes, Espumas e Géis Vaginais/efeitos adversos , Adulto Jovem
18.
Cult Health Sex ; 18(9): 1081-91, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27093238

RESUMO

Oral pre-exposure prophylaxis (PrEP) using the antiretroviral drug emtricitabine/tenofovir disoproxil fumarate (Truvada) has been shown to dramatically reduce the risk of HIV acquisition for women at higher risk of infection if taken daily. Understanding when and why women would intentionally stop using an efficacious oral PrEP drug within the context of their 'normal' daily lives is essential for delivering effective PrEP risk-reduction counselling. As part of a larger study, we conducted 60 qualitative interviews with women at higher risk of HIV in Bondo, Kenya, and Pretoria, South Africa. Participants charted their sexual contacts over the previous six months, indicated whether they would have taken PrEP if available and discussed whether and why they would have suspended PrEP use. Nearly all participants said they would have used PrEP in the previous six months; half indicated they would have suspended PrEP use at some point. Participants' reasons for an extended break from PrEP were related to partnership dynamics (e.g., perceived low risk of a stable partner) and phases of life (e.g., trying to conceive). Life events (e.g., holidays and travel) could prompt shorter breaks in PrEP use. These circumstances may or may not correspond to actual contexts of lower risk, highlighting the importance of tailored PrEP risk-reduction counselling.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/prevenção & controle , Adesão à Medicação , Profilaxia Pré-Exposição/métodos , Adulto , Feminino , Humanos , Quênia , Pesquisa Qualitativa , Comportamento de Redução do Risco , Sexo Seguro , Comportamento Sexual , Parceiros Sexuais , África do Sul , Viagem
19.
N Engl J Med ; 367(5): 411-22, 2012 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-22784040

RESUMO

BACKGROUND: Preexposure prophylaxis with antiretroviral drugs has been effective in the prevention of human immunodeficiency virus (HIV) infection in some trials but not in others. METHODS: In this randomized, double-blind, placebo-controlled trial, we assigned 2120 HIV-negative women in Kenya, South Africa, and Tanzania to receive either a combination of tenofovir disoproxil fumarate and emtricitabine (TDF-FTC) or placebo once daily. The primary objective was to assess the effectiveness of TDF-FTC in preventing HIV acquisition and to evaluate safety. RESULTS: HIV infections occurred in 33 women in the TDF-FTC group (incidence rate, 4.7 per 100 person-years) and in 35 in the placebo group (incidence rate, 5.0 per 100 person-years), for an estimated hazard ratio in the TDF-FTC group of 0.94 (95% confidence interval, 0.59 to 1.52; P=0.81). The proportions of women with nausea, vomiting, or elevated alanine aminotransferase levels were significantly higher in the TDF-FTC group (P=0.04, P<0.001, and P=0.03, respectively). Rates of drug discontinuation because of hepatic or renal abnormalities were higher in the TDF-FTC group (4.7%) than in the placebo group (3.0%, P=0.051). Less than 40% of the HIV-uninfected women in the TDF-FTC group had evidence of recent pill use at visits that were matched to the HIV-infection window for women with seroconversion. The study was stopped early, on April 18, 2011, because of lack of efficacy. CONCLUSIONS: Prophylaxis with TDF-FTC did not significantly reduce the rate of HIV infection and was associated with increased rates of side effects, as compared with placebo. Despite substantial counseling efforts, drug adherence appeared to be low. (Supported by the U.S. Agency for International Development and others; FEM-PrEP ClinicalTrials.gov number, NCT00625404.).


Assuntos
Adenina/análogos & derivados , Antirretrovirais/uso terapêutico , Desoxicitidina/análogos & derivados , Infecções por HIV/prevenção & controle , HIV-1 , Organofosfonatos/uso terapêutico , Adenina/efeitos adversos , Adenina/uso terapêutico , Adolescente , Adulto , Alanina Transaminase/sangue , Antirretrovirais/efeitos adversos , Estudos de Casos e Controles , Desoxicitidina/efeitos adversos , Desoxicitidina/uso terapêutico , Método Duplo-Cego , Combinação de Medicamentos , Farmacorresistência Viral , Emtricitabina , Feminino , Infecções por HIV/epidemiologia , Soropositividade para HIV , HIV-1/genética , HIV-1/isolamento & purificação , Humanos , Incidência , Estimativa de Kaplan-Meier , Adesão à Medicação , Organofosfonatos/efeitos adversos , RNA Viral/sangue , Assunção de Riscos , Comportamento Sexual/estatística & dados numéricos , Tenofovir , Falha de Tratamento , Carga Viral , Adulto Jovem
20.
Cult Health Sex ; 17(8): 1004-20, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25913101

RESUMO

Gender norms that privilege men's sexual power and pleasure, and distrust of condom use in intimate relationships, leave women vulnerable to HIV and other sexually transmitted infections. Vaginal microbicides allow women to exert a degree of control over their sexual health, through responsibility for product insertion as well as the possibility of covert use. In practice, however, the uptake of new HIV-prevention products is heavily influenced by partnership dynamics. This paper presents a secondary analysis of data from two qualitative sub-studies conducted during a Phase 3 microbicide efficacy trial in South Africa. Using transcripts from in-depth interviews and focus group discussions with 278 female trial participants and 27 male partners, we investigated the extent to which women disclosed microbicide use to their partners, and the level and types of male engagement with microbicide use. Most women chose to communicate with their partners about the trial, but the timing and content of associated discussions differed according to their motivation for disclosure. Men provided their partners with both moral and practical support, but reported a desire for greater involvement in decision-making surrounding microbicide uptake and use. The findings inform recommendations for constructive male participation in future trials and, ultimately, introduction of a marketed product.


Assuntos
Anti-Infecciosos/administração & dosagem , Infecções por HIV/prevenção & controle , Infecções por HIV/psicologia , Profilaxia Pré-Exposição/métodos , Parceiros Sexuais/psicologia , Administração Intravaginal , Adulto , Transmissão de Doença Infecciosa/prevenção & controle , Feminino , Grupos Focais , Humanos , Masculino , Comportamento Sexual/psicologia , África do Sul , Cremes, Espumas e Géis Vaginais/administração & dosagem , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa