Development of a Zimbabwean child growth curve and its comparison with the World Health Organization child growth standards.

BACKGROUND: There is limited research that describes the growth trajectories of African children. The development of World Health Organization (WHO) growth standards considered a sample of children who lived in environments optimum for human growth. AIM: This study aimed to develop weight-for-age and height-for-age growth curves from the Zimbabwean 2018 National Nutrition Survey and compare them with the WHO growth standards. SETTING: Study participants were recruited from all districts in Zimbabwe. METHODS: Height-for-age and weight-for-age data collected from 32 248 children were used to develop the Zimbabwean references. Smooth growth curves (height, weight and body mass index [BMI]-for-age) were estimated with the Lambda Mu Sigma (LMS) method and compared with the WHO growth standards. RESULTS: Zimbabwean children were shorter and weighed less in comparison with the WHO growth standards. The -2 standard deviation (s.d.) Z-score curves (height-for-age) for Zimbabwean children (boys and girls) were below the -1 s.d. Z-score curves of the WHO growth standards. The Zimbabwean Z-scores (BMI-for-age) values above -1 s.d. were significantly higher in comparison with the corresponding WHO growth standards. CONCLUSION: Utilising the WHO growth standards would diagnose a higher proportion of Zimbabwean children as stunted whilst underestimating the proportion at risk of obesity. The WHO growth standards lack a consideration of the geographical, economic, political and environmental constraints existing between countries.

Novavax NVX-COV2373 triggers potent neutralization of Omicron sub-lineages

The SARS-CoV-2 Omicron (B.1.1.529) Variant of Concern (VOC) and its sub-lineages (including BA.2, BA.4/5, BA.2.12.1) contain spike mutations that confer high level resistance to neutralizing antibodies. The NVX-CoV2373 vaccine, a protein nanoparticle vaccine, has value in countries with constrained cold-chain requirements. Here we report neutralizing titers following two or three doses of NVX-CoV2373. We show that after two doses, Omicron sub-lineages BA.1 and BA.4 were resistant to neutralization by 72% (21/29) and 59% (17/29) of samples. However, after a third dose of NVX-CoV2373, we observed high titers against Omicron BA.1 (GMT: 1,197) and BA.4 (GMT: 582), with responses similar in magnitude to those triggered by three doses of an mRNA vaccine. These data are of particular relevance as BA.4 is emerging to become the dominant strain in many locations, and highlight the potential utility of the NVX-CoV2373 vaccine as a booster in resource-limited environments.

COVID-19 and HIV viral load suppression in children andadolescents in Durban, South Africa

Background: The coronavirus disease 2019 (COVID-19) pandemic poses challenges to paediatric and adolescent HIV treatment programme. Modelling exercises raised concerns over potential impact of disruptions. Objectives: To describe the impact of the COVID-19 pandemic on viral load (VL) testing among infants, children and adolescents on antiretroviral treatment (ART) in Durban, South Africa. Method: Routinely collected, aggregated data of monthly VL counts done on all those less than 19 years old from January 2018 to January 2022 was analysed. An interrupted time series analysis using a Prais-Winsten linear regression model, including terms for lockdowns and excess mortality determined VL trends. Results: The unadjusted mean VL was 2166 (confidence interval [CI]: 252.2) and 2016 (CI: 241.9), P = 0.039, and percentage VL suppression rates (72.9%, CI: 2.4% vs 73.6%, CI: 1.8%) across COVID and pre-COVID periods, showing no significant difference, P = 0.262. In the interrupted time series analysis, modelled monthly VL counts did not differ significantly by lockdown level (e.g., level 5 lockdown: ­210.5 VLs, 95% CI: ­483.0 to +62.1, P = 0.138) or excess mortality (­0.1, 95% CI: ­6.3 to 6.1, P = 0.969). A significant downward trend in VL testing over time, including during the pre-COVID-19 period (­6.6 VL per month, 95% CI: ­10.4 to ­2.7, P = 0.002), was identified. Conclusion: Viral load suppression for children and adolescents were not negatively affected by COVID-19. A trend of decrease in VL testing predated COVID-19. What this study adds: Evidence presented that HIV VL testing and suppression rates in children and adolescents in a high burden setting were sustained through the COVID pandemic.

Preliminary Efficacy of the NVX-CoV2373 Covid-19 Vaccine Against the B.1.351 Variant

BackgroundThe emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants threatens progress toward control of the Covid-19 pandemic. Evaluation of Covid-19 vaccine efficacy against SARS-CoV-2 variants is urgently needed to inform vaccine development and use. MethodsIn this phase 2a/b, multicenter, randomized, observer-blinded, placebo-controlled trial in South Africa, healthy human immunodeficiency virus (HIV)-negative adults (18 to 84 years) or medically stable people living with HIV (PLWH) (18 to 84 years) were randomized in a 1:1 ratio to receive two doses, administered 21 days apart, of either NVX-CoV2373 nanoparticle vaccine (5 {micro}g recombinant spike protein with 50 {micro}g Matrix-M1 adjuvant) or placebo. The primary endpoints were safety and vaccine efficacy [≥]7 days following the second dose against laboratory-confirmed symptomatic Covid-19 in previously SARS-CoV-2 uninfected participants. ResultsA total of 4387 participants were randomized and dosed at least once, 2199 with NVX-CoV2373 and 2188 with placebo. Approximately 30% of participants were seropositive at baseline. Among 2684 baseline seronegative participants (94% HIV-negative; 6% PLWH), there were 15 and 29 predominantly mild to moderate Covid-19 cases in NVX-CoV2373 and placebo recipients, respectively; vaccine efficacy was 49.4% (95% confidence interval [CI]: 6.1 to 72.8). Efficacy in HIV-negative participants was 60.1% (95% CI: 19.9 to 80.1), and did not differ by baseline serostatus. Of the primary endpoint cases with available whole genome sequencing, 38 (92.7%) of 41 were the B.1.351 variant. Post-hoc vaccine efficacy against B.1.351 was 51.0% (95% CI: - 0.6 to 76.2) in HIV-negative participants. Among placebo recipients, the incidence of symptomatic Covid-19 was similar in baseline seronegative vs baseline seropositive participants during the first 2 months of follow-up (5.3% vs 5.2%). Preliminary local and systemic reactogenicity were primarily mild to moderate and transient, and higher with NVX-CoV2373; serious adverse events were rare in both groups. ConclusionsThe NVX-CoV2373 vaccine was efficacious in preventing Covid-19, which was predominantly mild to moderate and due to the B.1.351 variant, while evidence of prior infection with the presumptive original SARS-CoV-2 did not confer protection against probable B.1.351 disease. (Funded by Novavax, The Bill and Melinda Gates Foundation, and the Coalition for Epidemic Preparedness Innovations; ClinicalTrials.gov number, NCT04533399)

The Effect of Lactose-Free Formula Feeds on Growth Responses among Severely Malnourished HIV-Infected Children in Durban; South Africa

Background. The co-occurrence of HIV infection and severe malnutrition contributes to high rates of morbidity and mortality among children in resource-limited settings. Lactose-free; ready-to-use therapeutic feeds (RUTFs) may be most appropriate in this population because of underlying mucosal damage secondary to inflammation and infection. Objectives. To describe the effect of lactose-free RUTFs on the growth parameters of severely malnourished HIV-infected children in Durban; South Africa (SA).Methods. This was a prospective; observational study of nutritional recovery in HIV-infected; severely malnourished children; aged 6 months to 5 years; who received lactose-free RUTFs following admission to King Edward VIII Hospital in Durban; SA. The primary outcome was nutritional recovery; defined as 15% weight gain from enrolment to end of study. Secondary outcomes included z-scores for weight-for-height; weight-for-age; height-for-age; triceps skinfold thickness (SFT) and subscapular SFT calculated at baseline and 7; 14; 30 and 45 days after admission. Univariate analysis was done to compare outcomes among antiretroviral therapy (ART)-naive and ART-experienced children; the effect of ART on nutritional recovery was evaluated in a logistic regression model. Results. A significant improvement in most nutritional parameters was found at 45 days; 59% of children attained nutritional recovery. There was no significant difference in the proportion of children reaching recovery based on ART status at admission (p=0.08).Conclusion. Lactose-free formula feeds may be an effective strategy for nutritional rehabilitation of severely malnourished and HIV-infected children in resource-limited settings. It remains to be determined how ART initiation affects nutritional recovery in these children