Correction: Impact of Maternal HIV Seroconversion during Pregnancy on Early Mother to Child Transmission of HIV (MTCT) Measured at 4-8 Weeks Postpartum in South Africa 2011-2012: A National Population-Based Evaluation

Physiologically Based Pharmacokinetic Modeling in Neonates: Current Status and Future Perspectives

Rational drug use in special populations is a clinical problem that doctors and pharma-cists must consider seriously. Neonates are the most physiologically immature and vulnerable to drug dosing. There is a pronounced difference in the anatomical and physiological profiles be-tween neonates and older people, affecting the absorption, distribution, metabolism, and excretion of drugs in vivo, ultimately leading to changes in drug concentration. Thus, dose adjustments in neonates are necessary to achieve adequate therapeutic concentrations and avoid drug toxicity. Over the past few decades, modeling and simulation techniques, especially physiologically based pharmacokinetic (PBPK) modeling, have been increasingly used in pediatric drug development and clinical therapy. This rigorously designed and verified model can effectively compensate for the deficiencies of clinical trials in neonates, provide a valuable reference for clinical research design, and even replace some clinical trials to predict drug plasma concentrations in newborns. This review introduces previous findings regarding age-dependent physiological changes and pathological factors affecting neonatal pharmacokinetics, along with their research means. The application of PBPK modeling in neonatal pharmacokinetic studies of various medications is also reviewed. Based on this, we propose future perspectives on neonatal PBPK modeling and hope for its broader application.

Acceptability of a Combination Adherence Strategy to Support HIV Antiretroviral Therapy and Pre-exposure Prophylaxis Adherence During Pregnancy and Breastfeeding in Malawi

In two parallel pilot studies, we implemented a combination adherence intervention of patient-centered counselling and adherence supporter training, tailored to support HIV treatment (i.e., antiretroviral therapy) or prevention (i.e., pre-exposure prophylaxis, or PrEP) during pregnancy and breastfeeding. Using a mixed-methods approach, we evaluated the intervention's acceptability. We investigated engagement, satisfaction, and discussion content via survey to all 151 participants assigned to the intervention arm (51 women living with HIV, 100 PrEP-eligible women without HIV). We also conducted serial in-depth interviews with a subgroup (n = 40) at enrollment, three months, and six months. In the quantitative analysis, the vast majority reported high satisfaction with intervention components and expressed desire to receive it in the future, if made available. These findings were supported in the qualitative analysis, with favorable comments about counselor engagement, intervention content and types of support received from adherence supporters. Overall, these results demonstrate high acceptability and provide support for HIV status-neutral interventions for antiretroviral adherence.

Influences on PrEP Uptake and Adherence Among South African Women During Periconception and Pregnancy: A Qualitative Analysis

Pre-exposure prophylaxis (PrEP) is highly effective for HIV prevention, yet PrEP delivery to women in periconception and pregnancy has lagged. We report qualitative research from a study evaluating PrEP use as part of safer conception care for 330 South African women. Fifty-two semi-structured interviews were conducted with 25 study participants to identify influences on PrEP adherence. Influences were: (1) changing proximity to male partners; (2) COVID-19 lockdown; (3) mobile lifestyle; (4) PrEP-related stigma; (5) disclosure of PrEP use; and (6) pregnancy and motherhood. Data also revealed important contextual information shaping adherence influences for women, including: (a) not living with partners, (b) partners as drivers of pregnancy intention, and (c) feeling at high risk for HIV. Disclosure of PrEP use, addressing stigma, strategies for traveling with pills, and counseling on prevention effective adherence are promising components of PrEP-inclusive HIV prevention interventions for South African women who are pregnant or planning pregnancy.

Prevalence, incidence and seroconversion of HIV and Syphilis infections among pregnant women of South Africa

Background

Pregnant women in South Africa suffer from HIV and syphilis infections resulting in negative pregnancy outcomes. Little is known about the prevalence, incidence, seroconversion, and associated risk factors for those attending a midwife run obstetric unit.

Methods

A retrospective cohort study was undertaken among pregnant women attending antenatal clinic from January to December 2018. Logistic regression was conducted to determine the risk factors for HIV and syphilis.

Results

The prevalence of HIV and syphilis were 44.3% (95% confidence interval [CI]; 41.6:46.7) and 3.8% (95% CI; 3.1:4.1), respectively. The seroconversion and incidence for HIV were 4.0% (95% CI; 3.6:4.6) and 17.1 per 100 person-years, and for syphilis 2.6% (95% CI; 2.3:2.8) and 10.9 per 100 person-years, respectively. Significant predictors for HIV prevalence were ages: ages < 20 years, Odds ratio (OR) = 0.11 (p < 0.05), ages 20–24 years, OR = 0.19 (p < 0.05) and ages 25–29 years, OR = 0.38 (p < 0.05); gestational age: second trimester, OR = 0.68 (p < 0.05) and non-reactive syphilis, OR = 0.45 (p < 0.05). Age was the predictor for HIV incidence or seroconversion (age < 20 year, OR = 0.12, p = 0.01). Predictors for syphilis were ages < 20 years, OR = 0.11 (p < 0.05), ages 20–24 years and HIV status. Gestational age > 27 weeks were nine times (OR = 9.2, p = 0.03) more likely to seroconvert to syphilis.

Conclusions

The present study found high rates of seroprevalence, seroconversion and incidence of HIV and syphilis among pregnant women.

Recent HIV infection among pregnant women in the 2017 antenatal sentinel cross-sectional survey, South Africa: Assay-based incidence measurement

Introduction

New HIV infection during pre-conception and pregnancy is a significant contributor of mother–to–child transmission of HIV in South Africa. This study estimated HIV incidence (defined as new infection within the last one year from the time of the survey which included both new infections occurred during pregnancy or just before pregnancy) among pregnant women and described the characteristics of recently infected pregnant women at national level.

Methods

Between 1 October and 15 November 2017, we conducted a national cross–sectional survey among pregnant women aged 15–49 years old attending antenatal care at 1,595 public facilities. Blood specimens were collected from pregnant women and tested for HIV in a centralised laboratory. Plasma viral load and Limiting Antigen Avidity Enzyme Immunosorbent Assay (LAg) tests were further performed on HIV positive specimens to differentiate between recent and long–term infections. Recent infection was defined as infection that occurred within one year from the date of collection of blood specimen for the survey. Data on age, age of partner, and marital status were collected through interviews. Women whose specimens were classified as recent by LAg assay and with viral loads >1,000 copies/mL were considered as recently infected. The calculated proportion of HIV positive women with recent infection was adjusted for assay–specific parameters to estimate annual incidence. Survey multinomial logistic regression was used to examine factors associated with being recently infected using HIV negative women as a reference group. Age–disparate relationship was defined as having a partner 5 or more years older.

Results

Of 10,049 HIV positive participants with LAg and viral load data, 1.4% (136) were identified as recently infected. The annual HIV incidence was 1.5% (95% confidence interval (CI): 1.2–1.7). In multivariable analyses, being single (adjusted odds ratio, aOR: 3.4, 95% CI: 1.8–6.2) or cohabiting (aOR: 3.8, 95% CI: 1.8–7.7), compared to being married as well as being in an age–disparate relationship among young women (aOR: 3.1, 95% CI: 2.0–4.7; reference group: young women (15–24years) whose partners were not 5 years or more older) were associated with higher odds of recent infection.

Conclusions

Compared to previous studies among pregnant women, the incidence estimated in this study was substantially lower. However, the UNAIDS target to reduce incidence by 75% by 2020 (which is equivalent to reducing incidence to <1%) has not been met. The implementation of HIV prevention and treatment interventions should be intensified, targeting young women engaged in age–disparate relationship and unmarried women to fast track progress towards the UNAIDS target.

Safety, Tolerability, and Pharmacokinetics of the Broadly Neutralizing Human Immunodeficiency Virus (HIV)-1 Monoclonal Antibody VRC01 in HIV-Exposed Newborn Infants

BACKGROUND

Although mother-to-child human immunodeficiency virus (HIV) transmission has dramatically decreased with maternal antiretroviral therapy, breast milk transmission accounts for most of the 180 000 new infant HIV infections annually. Broadly neutralizing antibodies (bNAb) may further reduce transmission.

METHODS

A Phase 1 safety and pharmacokinetic study was conducted: a single subcutaneous (SC) dose of 20 or 40 mg/kg (Dose Groups 1 and 2, respectively) of the bNAb VRC01 was administered to HIV-exposed infants soon after birth. Breastfeeding infants (Dose Group 3) received 40 mg/kg SC VRC01 after birth and then 20 mg/kg/dose SC monthly. All infants received appropriate antiretroviral prophylaxis.

RESULTS

Forty infants were enrolled (21 in the United States, 19 in Africa). Subcutaneous VRC01 was safe and well tolerated with only mild-to-moderate local reactions, primarily erythema, which rapidly resolved. For multiple-dose infants, local reactions decreased with subsequent injections. VRC01 was rapidly absorbed after administration, with peak concentrations 1-6 days postdose. The 40 mg/kg dose resulted in 13 of 14 infants achieving the serum 50 micrograms (mcg)/mL target at day 28. Dose Group 3 infants maintained concentrations greater than 50 mcg/mL throughout breastfeeding.

CONCLUSIONS

Subcutaneous VRC01 as single or multiple doses is safe and well tolerated in very young infants and is suitable for further study to prevent HIV transmission in infants.

Risk perception and sex behaviour in pregnancy and breastfeeding in high HIV prevalence settings: Programmatic implications for PrEP delivery

HIV acquisition during pregnancy and breastfeeding significantly contributes toward paediatric HIV infection; however, little is known about risk behaviours in HIV-uninfected pregnant and postpartum women. We conducted twenty-six in-depth-interviews between July and December 2016 using a semi-structured interview guide among HIV-uninfected pregnant and recently postpartum women at-risk of HIV acquisition (defined as reporting ≥1 of the following: partner's serostatus unknown or HIV-infected, recent condomless sex in pregnancy, and/or alcohol use during pregnancy) who attended primary healthcare services. Our study contextualizes factors related to risky sexual behaviours during pregnancy and postpartum periods and assesses knowledge and hypothetical acceptability of pre-exposure prophylaxis (PrEP) in pregnancy. Translated and transcribed data were coded and analysed by three researchers using a thematic analysis approach. In interviews with HIV-uninfected pregnant/postpartum women at-risk of HIV acquisition, we identified common themes associated with sexual risk behaviours during pregnancy, including: lack of control over decisions in sex and condom use in pregnancy, low perceived risk (e.g. beliefs that their partner has the same HIV-negative serostatus), and socio-cultural beliefs around condom use during pregnancy (e.g. contact with sperm is essential for baby's development). PrEP knowledge was low among HIV-uninfected pregnant and breastfeeding women, and potential acceptability was good, though primary concerns were around the potential impact on the infant. While mothers presented a clear desire to protect themselves from HIV acquisition once pregnant, they also reported lack of control, and socio-cultural beliefs, like sex is good for the baby, that increased their risk of seroconversion. Mothers had limited PrEP awareness but reported hypothetical willingness to use PrEP because of concerns over HIV acquisition and onward mother to child transmission.