Sexually transmitted infections, bacterial vaginosis and genital inflammation as risk factors of HIV acquisition in adolescent girls and young women in South Africa

Background: In South Africa, young women are at increased risk of HIV infection, predominantly through heterosexual contact. Socio-behavioural and biological factors most likely play an important role at increasing risk. BV, STIs and genital yeast infections are known to influence HIV risk, although few studies have been conducted in African adolescent girls and young women (AGYW). Understanding the role of behavioural and biological risk factors in this key population is essential to inform on new prevention strategies. Aims: (1) To define the prevalence of sexual risk behaviour, bacterial vaginosis (BV), sexually transmitted infections (STIs), and genital fungal infections in South African AGYW; (2) to assess the relationship between symptoms and an etiological STI diagnosis; (3) to evaluate the influence of electronic and paper-based data collection methods on reported demographics and sexual risk behavior; (4) to examine the impact of non-infectious and infectious causes on genital inflammatory cytokine profiles; and (5) to investigate the use of cytokine biomarkers to identify young women with asymptomatic vaginal dysbiosis and STIs. Approach: To address these aims, the multi-center Women's Initiative in Sexual Health (WISH) study was conducted as a longitudinal observational trial that included HIV-negative, South African AGYW between the ages of 16-22 (EDCTP Strategic Primer 2013-2015), of which 149 from Masiphumelele, Cape Town were enrolled longitudinally for three visits and the 149 from Soweto, Johannesburg were seen cross-sectionally. Genital samples were collected to test for STIs (including Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, Mycoplasma genitalium, herpes simplex virus (HSV)-1 and -2, Haemophilus ducreyi, Treponema pallidum and Lymphogranuloma venerum), BV (Nugent scoring) and yeast infections, to assess vaginal pH, and to measure prostate specific antigen (PSA) as a marker for the presence of semen. Multi-locus sequence typing (MLST) was performed on samples positive for C. trachomatis. In addition, 44 inflammatory, adaptive, regulatory cytokines, chemokines and growth factors were measured in genital secretions byLuminexR. Concentrations of sex hormones (estrogen, progesterone and luteinizing hormone), HSV-serology and cotinine (smoking) were measured in blood plasma. A HIV test was done at screening and each visit. Only HIV negative women were enrolled in the study Results: The prevalence of BV (Nugent 7-10) in South African AGYW were similarly high in Masiphumelele and Soweto (48% and 45%, respectively), as was intermediate microbiota (12% and 16%, respectively). In addition, 40% of South African AGYW were infected with any STI. C. trachomatis and N. gonorrhoeae were more prevalent in Masiphumelele compared to Soweto (42% vs. 18% for C. trachomatis and 11% vs. 5% for N. gonorrhoeae, respectively), while the prevalence of the other STIs tested for, including T. vaginalis, M. genitalium and HSV-2, was similar at both sites. Two-thirds (67%) of AGYW had HPV infection while 10% had a fungal infection. The indicators of risky behavior (including partner's HIV status being unknown [57%], having unprotected vaginal sex in the last three months [40%], and being in HIV discordant relationships [20%]) were high in this population, and tended to be more prevalent in Soweto than Masiphumelele. It was striking that only 24% of women with a diagnosed STI or BV were symptomatic, underlining the inadequacy of syndromic management in this population. The most sensitive symptom in this cohort was dysuria, which had 50% sensitivity in diagnosing a STI, and the least sensitive was abnormal vaginal discharge with a sensitivity of 22%. Having multiple, concurrent conditions (multiple STIs or a STI and BV) did not increase the symptom frequency or severity. In Chapter 3, two methods were compared to obtain demographic and sexual risk behaviour data – an electronic tablet device and a paper-based questionnaire. This was done to explore the presence of reporting bias and to improve the frequency of it in the cohort. There were no obvious differences seen in the reporting of risk between the two arms. It was striking that geographical differences in risk reporting were observed, with AGYW from Soweto reporting a higher frequency of HIV discordant relationships and intergenerational relationships than women from Masiphumelele, independently of the data collection method used. As genital inflammatory cytokines are known to influence HIV risk, physiological and pathological factors that may influence the genital cytokine profiles of AGYW were examined in Chapter 4 and 5. A change of vaginal pH appeared to play a crucial role, as it was associated with a significant increase in half (22/44) of the cytokines measured in AGYW with no STIs, no yeast infections and a Nugent score ≤3. Further, in these adolescents that one would consider healthy, a pronounced effect was seen with hormonal contraception choice, with Net-En significantly increasing the median concentrations of 31/44 cytokines, and DMPA upregulating 27/44 cytokine concentrations. Recent sex (being PSA positive) did not influence genital inflammation. Next, the impact of BV, viral STIs (HPV and HSV-2) and yeast infections on genital inflammation in adolescents was investigated. BV was the most inflammatory condition seen with 34/44 cytokines being upregulated. Interestingly, BV was also associated with downregulation of chemokines at both sites, including GRO-α, IP-10 and MIG. BV alone was more inflammatory than coinfection of BV with C. trachomatis, BV with another STI, or BV, C. trachomatis and another STI. In this cohort, HPV and HSV-2 shedding did not influence genital inflammation. In Chapter 5, the influence of bacterial and parasitic STIs (including C. trachomatis, N. gonorrhoeae, T. vaginalis and M. genitalium) on the genital inflammatory profile was explored. C. trachomatis and T. vaginalis were equally inflammatory, with 23/44 cytokines being elevated. M. genitalium infections had a very little impact with only GM-CSF being significantly downregulated in Masiphumelele, while N. gonorrhoea infection did not influence the genital inflammatory milieu. Geographical variation in genital cytokine responses were observed in adolescents infected with T. vaginalis, which was moderately inflammatory in AGYW from Masiphumelele but not in AGYW from Soweto. With C. trachomatis infection, however, there was a more pronounced inflammatory response seen in adolescents from Soweto (where 23/44 genital cytokines were significantly increased) than those from Masiphumelele (no cytokines were changed), compared to adolescents with no STIs, no yeast infections and a Nugent score ≤3. Using MLST, further differences were associated with C. trachomatis infection: sequence type (ST) 3 was the most inflammatory C. trachomatis ST detected with 14/44 cytokines upregulated; ST137 caused no significant changes in cytokine markers, and ST100b was the least inflammatory with four cytokines being down regulated. Exploring the relationship between years of sexual experience and C. trachomatis infection showed low levels of inflammation in women with only with <2 year of sexual experience (only MIG was upregulated), while C. trachomatis infection in AGYW with ≥2 years sexual experience was associated with an increase in 19/44 cytokines. Finally, in Chapter 6 the cytokine biomarkers IL-1α, IL-1β and IP-10 were evaluated in the classification of asymptomatic STIs, BV and intermediate microbiota. These biomarkers correctly classified 76% of women using their SoftcupR samples, 76% of women using lateral vaginal wall swabs and 73% using vulvovaginal swab. The addition of pH to the biomarkers model improved the classification (82%) and sensitivity (87%) of results, but reduced specificity (64%). The validation of these biomarkers could lead to the development of a point-of-care test that could be used to triage women into risk categories independently of symptoms. Conclusion: The results show a high prevalence of risky behavior, STIs and BV in this vulnerable population, with poor correlation between clinical symptoms and diagnosis of STIs or BV, with most cases in adolescents being asymptomatic. Injectable hormonal contraceptive use led to increased genital inflammation in adolescents. Despite the lack of symptoms, most cases of BV and STIs were associated with significantly elevated concentrations of genital cytokines in the genital mucosa of these at-risk adolescents compared to their uninfected counterparts, with variation in levels of inflammation seen by geographic location, type of infection, and years of sexual experience. These results supported the use of biomarkers as a potential method to identify at risk women. Overall, these findings highlight the urgent need to include adolescents in the design and testing of new HIV prevention strategies and the importance of active identification and management of any infection or dysbiosis in this key at risk population

Congenital cytomegalovirus in Sub-Saharan Africa—a narrative review with practice recommendations

Cytomegalovirus (CMV) is the most common cause of congenital infection internationally, occurring in 0.67% of births, and increasingly recognised as a major public health burden due to the potential for long-term neurodevelopmental and hearing impairment. This burden includes estimates of 10% of childhood cerebral palsy and up to 25% of childhood deafness. In Sub-Saharan Africa, where CMV-seroprevalence is almost ubiquitous, prevalence of congenital CMV (cCMV) is higher than the global average, and yet there is a dearth of research and initiatives to improve recognition, diagnosis and treatment. This narrative review outlines the epidemiology and clinical presentation of cCMV, discusses issues of case identification and treatment in Sub-Saharan Africa, and recommends a framework of strategies to address these challenges. Considering the significant burden of cCMV disease in this setting, it is undoubtably time we embark upon improving diagnosis and care for these infants

SARS-CoV-2 antibodies in adolescents living with perinatally acquired HIV

Data on children and adolescents with HIV and coronavirus disease 2019 (COVID-19) co-infection are limited. Clinical and antibody data related to COVID-19 infection in adolescents living with perinatally acquired HIV (ALPHIV) and originally enrolled in the Children with HIV Early Antiretroviral Therapy (CHER) study were collected. We present a descriptive analysis of 53 ALPHIV who were tested for anti-SARS-CoV-2 antibodies. Just over half (53%) of the adolescents tested had positive anti-SARS-CoV-2 antibodies with only one participant describing a prior history of possible symptomatic infection. Contribution: The study contributes to the understanding of SARS-CoV-2 infection and vaccination practices in HIV-positive adolescents

Machine learning outperformed logistic regression classification even with limit sample size: A model to predict pediatric HIV mortality and clinical progression to AIDS

Logistic regression (LR) is the most common prediction model in medicine. In recent years, supervised machine learning (ML) methods have gained popularity. However, there are many concerns about ML utility for small sample sizes. In this study, we aim to compare the performance of 7 algorithms in the prediction of 1-year mortality and clinical progression to AIDS in a small cohort of infants living with HIV from South Africa and Mozambique. The data set (n = 100) was randomly split into 70% training and 30% validation set. Seven algorithms (LR, Random Forest (RF), Support Vector Machine (SVM), K-Nearest Neighbor (KNN), Naive Bayes (NB), Artificial Neural Network (ANN), and Elastic Net) were compared. The variables included as predictors were the same across the models including sociodemographic, virologic, immunologic, and maternal status features. For each of the models, a parameter tuning was performed to select the best-performing hyperparameters using 5 times repeated 10-fold cross-validation. A confusion-matrix was built to assess their accuracy, sensitivity, and specificity. RF ranked as the best algorithm in terms of accuracy (82,8%), sensitivity (78%), and AUC (0,73). Regarding specificity and sensitivity, RF showed better performance than the other algorithms in the external validation and the highest AUC. LR showed lower performance compared with RF, SVM, or KNN. The outcome of children living with perinatally acquired HIV can be predicted with considerable accuracy using ML algorithms. Better models would benefit less specialized staff in limited resources countries to improve prompt referral in case of high-risk clinical progression

ChAdOx1 nCoV-19 (AZD1222) vaccine-induced Fc receptor binding tracks with differential susceptibility to COVID-19

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

Efficacy of primary series AZD1222 (ChAdOx1 nCoV-19) vaccination against SARS-CoV-2 variants of concern: Final analysis of a randomized, placebo-controlled, phase 1b/2 study in South African adults (COV005)

COVID-19 vaccine efficacy (VE) has been observed to vary against antigenically distinct SARS-CoV-2 variants of concern (VoC). Here we report the final analysis of VE and safety from COV005: a phase 1b/2, multicenter, double-blind, randomized, placebo-controlled study of primary series AZD1222 (ChAdOx1 nCoV-19) vaccination in South African adults aged 18-65 years. South Africa's first, second, and third waves of SARS-CoV-2 infections were respectively driven by the ancestral SARS-CoV-2 virus (wild type, WT), and SARS-CoV-2 Beta and Delta VoCs. VE against asymptomatic and symptomatic infection was 90.6% for WT, 6.7% for Beta and 77.1% for Delta. No cases of severe COVID-19 were documented ahead of unblinding. Safety was consistent with the interim analysis, with no new safety concerns identified. Notably, South Africa's Delta wave occurred ≥ 9 months after primary series vaccination, suggesting that primary series AZD1222 vaccination offers a good durability of protection, potentially due to an anamnestic response. Clinical trial identifier: CT.gov NCT04444674

Correction to: Microbial function and genital inflammation in young South African women at high risk of HIV infection

Correction to: Microbiome 8, 165 (2020) https://doi.org/10.1186/s40168-020-00932-

Potential for maternally administered vaccine for infant group B streptococcus

BACKGROUND : Natural history studies have correlated serotype-specific anti–capsular polysaccharide (CPS) IgG in newborns with a reduced risk of group B streptococcal disease. A hexavalent CPS–cross-reactive material 197 glycoconjugate vaccine (GBS6) is being developed as a maternal vaccine to prevent invasive group B streptococcus in young infants. METHODS : In an ongoing phase 2, placebo-controlled trial involving pregnant women, we assessed the safety and immunogenicity of a single dose of various GBS6 formulations and analyzed maternally transferred anti-CPS antibodies. In a parallel seroepidemiologic study that was conducted in the same population, we assessed serotype-specific anti-CPS IgG concentrations that were associated with a reduced risk of invasive disease among newborns through 89 days of age to define putative protective thresholds. RESULTS : Naturally acquired anti-CPS IgG concentrations were associated with a reduced risk of disease among infants in the seroepidemiologic study. IgG thresholds that were determined to be associated with 75 to 95% reductions in the risk of disease were 0.184 to 0.827 μg per milliliter. No GBS6-associated safety signals were observed among the mothers or infants. The incidence of adverse events and of serious adverse events were similar across the trial groups for both mothers and infants; more local reactions were observed in the groups that received GBS6 containing aluminum phosphate. Among the infants, the most common serious adverse events were minor congenital anomalies (umbilical hernia and congenital dermal melanocytosis). GBS6 induced maternal antibody responses to all serotypes, with maternal-to-infant antibody ratios of approximately 0.4 to 1.3, depending on the dose. The percentage of infants with anti-CPS IgG concentrations above 0.184 μg per milliliter varied according to serotype and formulation, with 57 to 97% of the infants having a seroresponse to the most immunogenic formulation. CONCLUSIONS : GBS6 elicited anti-CPS antibodies against group B streptococcus in pregnant women that were transferred to infants at levels associated with a reduced risk of invasive group B streptococcal disease.Pfizer and the Bill and Melinda Gates Foundation.http://www.nejm.orghj2024Medical MicrobiologySDG-03:Good heatlh and well-bein

Efficacy of primary series AZD1222 (ChAdOx1 nCoV-19) vaccination against SARS-CoV-2 variants of concern: Final analysis of a randomized, placebo-controlled, phase 1b/2 study in South African adults (COV005)

DATA AVAILABILITY : Data will be made available on request.COVID-19 vaccine efficacy (VE) has been observed to vary against antigenically distinct SARS-CoV-2 variants of concern (VoC). Here we report the final analysis of VE and safety from COV005: a phase 1b/2, multicenter, double-blind, randomized, placebo-controlled study of primary series AZD1222 (ChAdOx1 nCoV-19) vaccination in South African adults aged 18–65 years. South Africa’s first, second, and third waves of SARS-CoV-2 infections were respectively driven by the ancestral SARS-CoV-2 virus (wild type, WT), and SARS-CoV-2 Beta and Delta VoCs. VE against asymptomatic and symptomatic infection was 90.6% for WT, 6.7% for Beta and 77.1% for Delta. No cases of severe COVID-19 were documented ahead of unblinding. Safety was consistent with the interim analysis, with no new safety concerns identified. Notably, South Africa’s Delta wave occurred ≥ 9 months after primary series vaccination, suggesting that primary series AZD1222 vaccination offers a good durability of protection, potentially due to an anamnestic response. Clinical trial identifier: CT.gov NCT04444674.The UK Research and Innovation (for Vaccine supply), the Bill and Melinda Gates Foundation, and the South African Medical Research Council.http://www.elsevier.com/locate/vaccinehj2024Medical MicrobiologySDG-03:Good heatlh and well-bein

Safety and immunogenicity of the ChAdOx1 nCoV-19 (AZD1222) vaccine against SARS-CoV-2 in people living with and without HIV in South Africa: an interim analysis of a randomised, double-blind, placebo-controlled, phase 1B/2A trial.

BACKGROUND: People living with HIV are at an increased risk of fatal outcome when admitted to hospital for severe COVID-19 compared with HIV-negative individuals. We aimed to assess safety and immunogenicity of the ChAdOx1 nCoV-19 (AZD1222) vaccine in people with HIV and HIV-negative individuals in South Africa. METHODS: In this ongoing, double-blind, placebo-controlled, phase 1B/2A trial (COV005), people with HIV and HIV-negative participants aged 18-65 years were enrolled at seven South African locations and were randomly allocated (1:1) with full allocation concealment to receive a prime-boost regimen of ChAdOx1 nCoV-19, with two doses given 28 days apart. Eligibility criteria for people with HIV included being on antiretroviral therapy for at least 3 months, with a plasma HIV viral load of less than 1000 copies per mL. In this interim analysis, safety and reactogenicity was assessed in all individuals who received at least one dose of ChAdOx1 nCov 19 between enrolment and Jan 15, 2021. Primary immunogenicity analyses included participants who received two doses of trial intervention and were SARS-CoV-2 seronegative at baseline. This trial is registered with ClinicalTrials.gov, NCT04444674, and the Pan African Clinicals Trials Registry, PACTR202006922165132. FINDINGS: Between June 24 and Nov 12, 2020, 104 people with HIV and 70 HIV-negative individuals were enrolled. 102 people with HIV (52 vaccine; 50 placebo) and 56 HIV-negative participants (28 vaccine; 28 placebo) received the priming dose, 100 people with HIV (51 vaccine; 49 placebo) and 46 HIV-negative participants (24 vaccine; 22 placebo) received two doses (priming and booster). In participants seronegative for SARS-CoV-2 at baseline, there were 164 adverse events in those with HIV (86 vaccine; 78 placebo) and 237 in HIV-negative participants (95 vaccine; 142 placebo). Of seven serious adverse events, one severe fever in a HIV-negative participant was definitely related to trial intervention and one severely elevated alanine aminotranferase in a participant with HIV was unlikely related; five others were deemed unrelated. One person with HIV died (unlikely related). People with HIV and HIV-negative participants showed vaccine-induced serum IgG responses against wild-type Wuhan-1 Asp614Gly (also known as D614G). For participants seronegative for SARS-CoV-2 antigens at baseline, full-length spike geometric mean concentration (GMC) at day 28 was 163·7 binding antibody units (BAU)/mL (95% CI 89·9-298·1) for people with HIV (n=36) and 112·3 BAU/mL (61·7-204·4) for HIV-negative participants (n=23), with a rising day 42 GMC booster response in both groups. Baseline SARS-CoV-2 seropositive people with HIV demonstrated higher antibody responses after each vaccine dose than did people with HIV who were seronegative at baseline. High-level binding antibody cross-reactivity for the full-length spike and receptor-binding domain of the beta variant (B.1.351) was seen regardless of HIV status. In people with HIV who developed high titre responses, predominantly those who were receptor-binding domain seropositive at enrolment, neutralising activity against beta was retained. INTERPRETATION: ChAdOx1 nCoV-19 was well tolerated, showing favourable safety and immunogenicity in people with HIV, including heightened immunogenicity in SARS-CoV-2 baseline-seropositive participants. People with HIV showed cross-reactive binding antibodies to the beta variant and Asp614Gly wild-type, and high responders retained neutralisation against beta. FUNDING: The Bill & Melinda Gates Foundation, South African Medical Research Council, UK Research and Innovation, UK National Institute for Health Research, and the South African Medical Research Council