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"Cotton, Mark F"
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The Recombinant Bacille Calmette–Guérin Vaccine VPM1002: Ready for Clinical Efficacy Testing
by
Nieuwenhuizen, Natalie E.
,
Shaligram, Umesh
,
Kulkarni, Prasad S.
in
Acidification
,
Antigen presentation
,
Apoptosis
2017
The only licensed vaccine against tuberculosis (TB), bacille Calmette-Guérin (BCG), protects against severe extrapulmonary forms of TB but is virtually ineffective against the most prevalent form of the disease, pulmonary TB. BCG was genetically modified at the Max Planck Institute for Infection Biology to improve its immunogenicity by replacing the urease C encoding gene with the listeriolysin encoding gene from
. Listeriolysin perturbates the phagosomal membrane at acidic pH. Urease C is involved in neutralization of the phagosome harboring BCG. Its depletion allows for rapid phagosome acidification and promotes phagolysosome fusion. As a result, BCGΔ
::
(VPM1002) promotes apoptosis and autophagy and facilitates release of mycobacterial antigens into the cytosol. In preclinical studies, VPM1002 has been far more efficacious and safer than BCG. The vaccine was licensed to Vakzine Projekt Management and later sublicensed to the Serum Institute of India Pvt. Ltd., the largest vaccine producer in the world. The vaccine has passed phase I clinical trials in Germany and South Africa, demonstrating its safety and immunogenicity in young adults. It was also successfully tested in a phase IIa randomized clinical trial in healthy South African newborns and is currently undergoing a phase IIb study in HIV exposed and unexposed newborns. A phase II/III clinical trial will commence in India in 2017 to assess efficacy against recurrence of TB. The target indications for VPM1002 are newborn immunization to prevent TB as well as post-exposure immunization in adults to prevent TB recurrence. In addition, a Phase I trial in non-muscle invasive bladder cancer patients has been completed, and phase II trials are ongoing. This review describes the development of VPM1002 from the drawing board to its clinical assessment.
Journal Article
Pattern of Infectious Morbidity in HIV-Exposed Uninfected Infants and Children
by
Singer, Joel
,
Slogrove, Amy L.
,
Bettinger, Julie A.
in
Acquired immune deficiency syndrome
,
AIDS
,
Babies
2016
Almost 30% of children in Southern Africa are HIV exposed but uninfected (HEU) and experience exposures that could increase vulnerability to infectious diseases compared to HIV unexposed (HU) children. The mechanisms of HEU infant vulnerability remain ill-defined. This review seeks to appraise the existing clinical evidence of the pattern of HEU infant infectious morbidity to aid understanding of the potential mechanism of susceptibility.
A systematic search was conducted of scientific literature databases and conference proceedings up to December 2015 for studies comparing adequately defined HEU (in whom HIV-infection had been excluded through age-appropriate testing) and HU infants for all-cause mortality, all-cause hospitalization, or an infection-related morbidity. The systematic review was complemented by a narrative review of additional studies detailing the pattern of infectious morbidity experienced by HEU children without comparison to HU children or without conclusive exclusion of HIV-infection in HIV-exposed infants.
Only 3 of 22 eligible identified studies were designed to primarily compare HEU and HU infants for infectious morbidity. Fourteen were conducted prior to 2009 in the context of limited antiretroviral interventions. Three patterns emerge: (1) causes of morbidity and mortality in HEU infants are consistent with the common causes of childhood morbidity and mortality (pneumonia, diarrheal disease, and bacterial sepsis) but occur with greater severity in HEU infants resulting in higher mortality, more frequent hospitalization, and more severe manifestations of disease; (2) the greatest relative difference between HEU and HU infants in morbidity and mortality occurs beyond the neonatal period, during mid-infancy, having waned by the second year of life; and (3) HEU infants are at greater risk than HU infants for invasive streptococcal infections specifically Group B Streptococcus and Streptococcus pneumonia.
To definitively understand HEU infant infectious morbidity risk, substantially larger prospective studies with appropriate HU infant comparison groups are necessary. HEU children would benefit from collaboration among researchers to achieve the quality of evidence required to improve HEU infant outcomes globally. HEU infant health and well-being, beyond avoiding HIV-infection, deserves a more prominent position in the local and international HIV research agendas.
Journal Article
Early Antiretroviral Therapy and Mortality among HIV-Infected Infants
by
Babiker, Abdel G
,
Steyn, Jan
,
Gibb, Diana M
in
Acquired immune deficiency syndrome
,
AIDS
,
Anti-HIV Agents - administration & dosage
2008
The timing of initiation of antiretroviral therapy in HIV-infected infants has been debated, in part because of the potential long-term toxicity of the medication, the risk of resistance, adherence challenges, and cost. In this randomized trial involving 377 HIV-infected infants in South Africa, early initiation of antiretroviral therapy reduced infant mortality by 76% and the rate of HIV progression by 75%.
In this randomized trial involving 377 HIV-infected infants in South Africa, early initiation of antiretroviral therapy reduced infant mortality by 76 percent and the rate of HIV progression by 75 percent.
Infants with human immunodeficiency virus type 1 (HIV-1) infection have higher rates of disease progression and mortality than older children,
1
–
3
even with a high percentage of CD4 lymphocytes (CD4 percentage).
4
Whereas early initiation of antiretroviral therapy may be appropriate for infants, continuing treatment for life is problematic, given the limitations of the available drugs, the long-term toxicity of antiretroviral therapy, adherence issues, the risk of resistance to antiretroviral therapy, and limited resources. This trial addresses the optimal time of initiation and duration of antiretroviral therapy in infants with in utero or intrapartum HIV-1 infection. We hypothesized that early initiation . . .
Journal Article
A child with perinatal HIV infection and long-term sustained virological control following antiretroviral treatment cessation
2019
Understanding HIV remission in rare individuals who initiated antiretroviral therapy (ART) soon after infection and then discontinued, may inform HIV cure interventions. Here we describe features of virus and host of a perinatally HIV-1 infected child with long-term sustained virological control. The child received early limited ART in the Children with HIV Early antiRetroviral therapy (CHER) trial. At age 9.5 years, diagnostic tests for HIV are negative and the child has characteristics similar to uninfected children that include a high CD4:CD8 ratio, low T cell activation and low CCR5 expression. Virus persistence (HIV-1 DNA and plasma RNA) is confirmed with sensitive methods, but replication-competent virus is not detected. The child has weak HIV-specific antibody and T cell responses. Furthermore, we determine his
HLA
and
KIR
genotypes. This case aids in understanding post-treatment control and may help design of future intervention strategies.
Some perinatally HIV infected children who have received early antiretroviral therapy (ART) show long-term sustained virological control after ART cessation. Here the authors describe a case who, at age 9.5 years, shows normal CD4:CD8 T cell ratios and has no detectable levels of replication-competent virus.
Journal Article
Iron absorption and loss, and efficacy of iron supplementation with and without prebiotics in children with virally suppressed HIV: three prospective studies in South Africa
by
Goosen, Charlene
,
Zimmermann, Michael B.
,
Mikulic, Nadja
in
692/308/3187
,
692/699/255/1901
,
Absorption
2025
Children living with HIV are at risk for iron deficiency, yet optimal strategies for prevention and treatment remain unclear. Here, we investigate iron absorption, losses, and the efficacy and safety of oral iron supplementation with versus without prebiotics in three prospective studies in children with virally suppressed HIV in South Africa (NCT03572010, NCT04931641). In the first study, using stable iron isotopes, we show that iron absorption from iron-fortified maize porridge, a lipid-based nutrient supplement, and an oral iron supplement is comparable between children with HIV (
n
= 43) and without HIV (
n
= 45). In the second study, we use a stable iron isotope dilution method over a 6-month period to demonstrate that children with HIV (
n
= 29) absorb significantly less iron from their habitual diet than their uninfected peers (
n
= 36), while basal iron losses are similar. In the third study, a 12-week randomised, placebo-controlled, double-blind trial, iron-deficient children with HIV receiving iron with prebiotic galacto-oligosaccharides (
n
= 41) exhibit a 39% greater relative increase in serum ferritin (primary outcome) compared to those receiving iron with placebo (
n
= 42) (
p
= 0.053). They also report significantly fewer infection-related symptoms, with no significant differences in gut inflammation or enteropathogen carriage (secondary outcomes). Collectively, these findings indicate that while dietary iron absorption is reduced in children with virally suppressed HIV, supplemental and fortificant iron are well absorbed, and co-administration of iron supplements with prebiotics may improve efficacy and safety.
Children living with HIV face a heightened risk of iron deficiency, yet optimal prevention and treatment strategies remain elusive. In these three prospective studies in South African children living with HIV, the authors show reduced dietary iron absorption but adequate absorption from iron supplements. Prebiotics may enhance efficacy and safety of oral iron supplementation in iron-deficient children living with HIV.
Journal Article
Evaluating pediatric tuberculosis dosing guidelines: A model-based individual data pooled analysis
2023
The current World Health Organization (WHO) pediatric tuberculosis dosing guidelines lead to suboptimal drug exposures. Identifying factors altering the exposure of these drugs in children is essential for dose optimization. Pediatric pharmacokinetic studies are usually small, leading to high variability and uncertainty in pharmacokinetic results between studies. We pooled data from large pharmacokinetic studies to identify key covariates influencing drug exposure to optimize tuberculosis dosing in children.
We used nonlinear mixed-effects modeling to characterize the pharmacokinetics of rifampicin, isoniazid, and pyrazinamide, and investigated the association of human immunodeficiency virus (HIV), antiretroviral therapy (ART), drug formulation, age, and body size with their pharmacokinetics. Data from 387 children from South Africa, Zambia, Malawi, and India were available for analysis; 47% were female and 39% living with HIV (95% on ART). Median (range) age was 2.2 (0.2 to 15.0) years and weight 10.9 (3.2 to 59.3) kg. Body size (allometry) was used to scale clearance and volume of distribution of all 3 drugs. Age affected the bioavailability of rifampicin and isoniazid; at birth, children had 48.9% (95% confidence interval (CI) [36.0%, 61.8%]; p < 0.001) and 64.5% (95% CI [52.1%, 78.9%]; p < 0.001) of adult rifampicin and isoniazid bioavailability, respectively, and reached full adult bioavailability after 2 years of age for both drugs. Age also affected the clearance of all drugs (maturation), children reached 50% adult drug clearing capacity at around 3 months after birth and neared full maturation around 3 years of age. While HIV per se did not affect the pharmacokinetics of first-line tuberculosis drugs, rifampicin clearance was 22% lower (95% CI [13%, 28%]; p < 0.001) and pyrazinamide clearance was 49% higher (95% CI [39%, 57%]; p < 0.001) in children on lopinavir/ritonavir; isoniazid bioavailability was reduced by 39% (95% CI [32%, 45%]; p < 0.001) when simultaneously coadministered with lopinavir/ritonavir and was 37% lower (95% CI [22%, 52%]; p < 0.001) in children on efavirenz. Simulations of 2010 WHO-recommended pediatric tuberculosis doses revealed that, compared to adult values, rifampicin exposures are lower in most children, except those younger than 3 months, who experience relatively higher exposure for all drugs, due to immature clearance. Increasing the rifampicin doses in children older than 3 months by 75 mg for children weighing <25 kg and 150 mg for children weighing >25 kg could improve rifampicin exposures. Our analysis was limited by the differences in availability of covariates among the pooled studies.
Children older than 3 months have lower rifampicin exposures than adults and increasing their dose by 75 or 150 mg could improve therapy. Altered exposures in children with HIV is most likely caused by concomitant ART and not HIV per se. The importance of the drug-drug interactions with lopinavir/ritonavir and efavirenz should be evaluated further and considered in future dosing guidance.
ClinicalTrials.gov registration numbers; NCT02348177, NCT01637558, ISRCTN63579542.
Journal Article
Similar cortical morphometry trajectories from 5 to 9 years in children with perinatal HIV who started treatment before age 2 years and uninfected controls
by
van der Kouwe, Andre
,
Robertson, Frances
,
Meintjes, Ernesta M.
in
Adolescent
,
Animal Models
,
Antiretroviral drugs
2023
Background
Life-long early ART (started before age 2 years), often with periods of treatment interruption, is now the standard of care in pediatric HIV infection. Although cross-sectional studies have investigated HIV-related differences in cortical morphology in the setting of early ART and ART interruption, the long-term impact on cortical developmental trajectories is unclear. This study compares the longitudinal trajectories of cortical thickness and folding (gyrification) from age 5 to 9 years in a subset of children perinatally infected with HIV (CPHIV) from the Children with HIV Early antiRetroviral therapy (CHER) trial to age-matched children without HIV infection.
Methods
75 CHER participants in follow-up care at FAMCRU (Family Centre for Research with Ubuntu), as well as 66 age-matched controls, received magnetic resonance imaging (MRI) on a 3 T Siemens Allegra at ages 5, 7 and/or 9 years. MR images were processed, and cortical surfaces reconstructed using the
FreeSurfer
longitudinal processing stream. Vertex-wise linear mixed effects (LME) analyses were performed across the whole brain to compare the means and linear rates of change of cortical thickness and gyrification from 5 to 9 years between CPHIV and controls, as well as to examine effects of ART interruption.
Results
Children without HIV demonstrated generalized cortical thinning from 5 to 9 years, with the rate of thinning varying by region, as well as regional age-related gyrification increases. Overall, the means and developmental trajectories of cortical thickness and gyrification were similar in CPHIV. However, at an uncorrected
p
< 0.005, 6 regions were identified where the cortex of CPHIV was thicker than in uninfected children, namely bilateral insula, left supramarginal, lateral orbitofrontal and superior temporal, and right medial superior frontal regions. Planned ART interruption did not affect development of cortical morphometry.
Conclusions
Although our results suggest that normal development of cortical morphometry between the ages of 5 and 9 years is preserved in CPHIV who started ART early, these findings require further confirmation with longitudinal follow-up through the vulnerable adolescent period.
Journal Article
Early time-limited antiretroviral therapy versus deferred therapy in South African infants infected with HIV: results from the children with HIV early antiretroviral (CHER) randomised trial
by
Otwombe, Kennedy
,
Rabie, Helena
,
Gibb, Diana M
in
Africans
,
Anti-HIV Agents - administration & dosage
,
Anti-HIV Agents - therapeutic use
2013
Interim results from the children with HIV early antiretroviral (CHER) trial showed that early antiretroviral therapy (ART) was life-saving for infants infected with HIV. In view of the few treatment options and the potential toxicity associated with lifelong ART, in the CHER trial we compared early time-limited ART with deferred ART.
CHER was an open-label randomised controlled trial of HIV-infected asymptomatic infants younger than 12 weeks in two South African trial sites with a percentage of CD4-positive T lymphocytes (CD4%) of 25% or higher. 377 infants were randomly allocated to one of three groups: deferred ART (ART-Def), immediate ART for 40 weeks (ART-40W), or immediate ART for 96 weeks (ART-96W), with subsequent treatment interruption. The randomisation schedule was stratified by clinical site with permuted blocks of random sizes to balance the numbers of infants allocated to each group. Criteria for ART initiation in the ART-Def group and re-initiation after interruption in the other groups were CD4% less than 25% in infancy; otherwise, the criteria were CD4% less than 20% or Centers for Disease Control and Prevention severe stage B or stage C disease. Combination therapy of lopinavir–ritonavir, zidovudine, and lamivudine was the first-line treatment regimen at ART initiation and re-initiation. The primary endpoint was time to failure of first-line ART (immunological, clinical, or virological) or death. Comparisons were done by intention-to-treat analysis, with use of time-to-event methods. This trial is registered with ClinicalTrials.gov, number NCT00102960.
377 infants were enrolled, with a median age of 7·4 weeks, CD4% of 35%, and HIV RNA log 5·7 copies per mL. Median follow-up was 4·8 years; 34 infants (9%) were lost to follow-up. Median time to ART initiation in the ART-Def group was 20 weeks (IQR 16–25). Time to restarting of ART after interruption was 33 weeks (26–45) in ART-40W and 70 weeks (35–109) in ART-96W; at the end of the trial, 19% of patients in ART-40W and 32% of patients in ART-96W remained off ART. Proportions of follow-up time spent on ART were 81% in the ART-Def group, 70% in the ART-40W group, and 69% in the ART-96W group. 48 (38%) of 125 children in the ART-Def group, 32 (25%) of 126 in the ART-40W group, and 26 (21%) of 126 in the ART-96W group reached the primary endpoint. The hazard ratio, relative to ART-Def, was 0·59 (95% CI 0·38–0·93, p=0·02) for ART-40W and 0·47 (0·27–0·76, p=0·002) for ART-96W. Three children in ART-Def, three in ART-40W, and one in ART-96W switched to second-line ART.
Early time-limited ART had better clinical and immunological outcomes than deferred ART, with no evidence of excess disease progression during subsequent treatment interruption and less overall ART exposure than deferred ART. Longer time on primary ART permits longer subsequent interruption, with marginally better outcomes.
US National Institutes of Health.
Journal Article
An analysis of the HIV testing cascade of a group of HIV-exposed infants from birth to 18 months in peri-urban Khayelitsha, South Africa
by
Giddy, Janet
,
Pieters, Pauline
,
Wedderburn, Catherine J.
in
Analysis
,
Anti-HIV Agents - therapeutic use
,
Babies
2022
Despite the reduction of HIV mother-to-child transmission, there are concerns regarding transmission rate in the breastfeeding period. We describe the routine uptake of 6 or 10 (6/10) weeks, 9 months and 18 months testing, with and without tracing, in a cohort of infants who received HIV PCR testing at birth (birth PCR) (with and without point of care (POC) testing) in a peri-urban primary health care setting in Khayelitsha, South Africa.
In this cohort study conducted between November 2014 and February 2018, HIV-positive mothers and their HIV-exposed babies were recruited at birth and all babies were tested with birth PCR. Results of routine 6/10 weeks PCR, 9 months and 18 months testing were followed up by a patient tracer. We compared testing at 6/10 weeks with a subgroup from historical cohort who was not tested with birth PCR.
We found that the uptake of 6/10 weeks testing was 77%, compared to 82% with tracing. When including all infants in the cascade and comparing to a historical cohort without birth testing, we found that infants who tested a birth were 22% more likely to have a 6/10 weeks test compared to those not tested at birth. There was no significant difference between the uptake of 6/10 weeks testing after birth PCR POC versus birth PCR testing without POC. Uptake of 9 months and 18 months testing was 39% and 24% respectively. With intense tracing efforts, uptake increased to 45% and 34% respectively.
Uptake of HIV testing for HIV-exposed uninfected infants in the first 18 months of life shows good completion of the 6/10 weeks PCR but suboptimal uptake of HIV testing at 9 months and 18 months, despite tracing efforts. Birth PCR testing did not negatively affect uptake of the 6/10 weeks HIV test compared to no birth PCR testing.
Journal Article
HIV-1 Persistence in Children during Suppressive ART
by
Katusiime, Mary Grace
,
Kearney, Mary F.
,
Van Zyl, Gert U.
in
Adults
,
Anti-Retroviral Agents - therapeutic use
,
antiretroviral agents
2021
There is a growing number of perinatally HIV-1-infected children worldwide who must maintain life-long ART. In early life, HIV-1 infection is established in an immunologically inexperienced environment in which maternal ART and immune dynamics during pregnancy play a role in reservoir establishment. Children that initiated early antiretroviral therapy (ART) and maintained long-term suppression of viremia have smaller and less diverse HIV reservoirs than adults, although their proviral landscape during ART is reported to be similar to that of adults. The ability of these early infected cells to persist long-term through clonal expansion poses a major barrier to finding a cure. Furthermore, the effects of life-long HIV persistence and ART are yet to be understood, but growing evidence suggests that these individuals are at an increased risk for developing non-AIDS-related comorbidities, which underscores the need for an HIV cure.
Journal Article