247 research outputs found
Equity and coverage in the continuum of reproductive, maternal, newborn and child health services in Nepal-projecting the estimates on death averted using the LiST tool.
INTRODUCTION: The third Sustainable Development Goal, focused on health, includes two targets related to the reduction in maternal, newborn and under-five childhood mortality. We found it imperative to examine the equity and coverage of reproductive, maternal, newborn and child health (RMNCH) interventions from 2001 to 2016 in Nepal; and the death aversion that will take place during the SDG period. METHODS: We used the datasets from the Nepal Demographic Health Surveys (NDHS) 2001, 2006, 2011 and 2016. We calculated the coverage and equity for RMNCH interventions and the composite coverage index (CCI). Based on the Annualized Rate of Change (ARC) in the coverage for selected RMNCH indicators, we projected the trend for the RMNCH interventions by 2030. We used the Lives Saved Tools (LiST) tool to estimate the maternal, newborn, under-five childhood deaths and stillbirths averted. We categorised the interventions into four different patterns based on coverage and inequity gap. RESULTS: Between 2001 and 2016, a significant improvement is seen in the overall RMNCH intervention coverage-CCI increasing from 46 to 75%. The ARC was highest for skilled attendance at birth (11.7%) followed by care seeking for pneumonia (8.2%) between the same period. In 2016, the highest inequity existed for utilization of the skilled birth attendance services (51%), followed by antenatal care (18%). The inequity gap for basic immunization services reduced significantly from 27.4% in 2001 to 5% in 2016. If the current ARC continues, then an additional 3783 maternal deaths, 36,443 neonatal deaths, 66,883 under-five childhood deaths and 24,024 stillbirths is expected to be averted by the year 2030. CONCLUSION: Nepal has experienced an improvement in the coverage and equity in RMNCH interventions. Reducing inequities will improve coverage for skilled birth attendants and antenatal care. The current annual rate of change in RMNCH coverage will further reduce the maternal, neonatal, under-five childhood deaths and stillbirths
The generation of influenza-specific humoral responses is impaired in ST6Gal I-deficient mice.
Posttranslational modification of proteins, such as glycosylation, can impact cell signaling and function. ST6Gal I, a glycosyltransferase expressed by B cells, catalyzes the addition of alpha-2,6 sialic acid to galactose, a modification found on N-linked glycoproteins such as CD22, a negative regulator of B cell activation. We show that SNA lectin, which binds alpha-2,6 sialic acid linked to galactose, shows high binding on plasma blasts and germinal center B cells following viral infection, suggesting ST6Gal I expression remains high on activated B cells in vivo. To understand the relevance of this modification on the antiviral B cell immune response, we infected ST6Gal I(-/-) mice with influenza A/HKx31. We demonstrate that the loss of ST6Gal I expression results in similar influenza infectivity in the lung, but significantly reduced early influenza-specific IgM and IgG levels in the serum, as well as significantly reduced numbers of early viral-specific Ab-secreting cells. At later memory time points, ST6Gal I(-/-) mice show comparable numbers of IgG influenza-specific memory B cells and long-lived plasma cells, with similarly high antiviral IgG titers, with the exception of IgG2c. Finally, we adoptively transfer purified B cells from wild-type or ST6Gal I(-/-) mice into B cell-deficient (microMT(-/-)) mice. Recipient mice that received ST6Gal I(-/-) B cells demonstrated reduced influenza-specific IgM levels, but similar levels of influenza-specific IgG, compared with mice that received wild-type B cells. These data suggest that a B cell intrinsic defect partially contributes to the impaired antiviral humoral response
The association of childhood pneumonia with household air pollution in Nepal: evidence from Nepal demographic health surveys.
INTRODUCTION: Childhood pneumonia is a major cause of mortality worldwide while household air pollution (HAP) is a major contributor to childhood pneumonia in low and middle-income countries. This paper presents the prevalence trend of childhood pneumonia in Nepal and assesses its association with household air pollution. METHODS: The study analysed data from the 2006, 2011 and 2016 Nepal Demographic Health Surveys (NDHS). It calculated the prevalence of childhood pneumonia and the factors that cause household air pollution. The association of childhood pneumonia and HAP was assessed using univariate and multi-variate analysis. The population attributable fraction (PAF) of indoor pollution for causing pneumonia was calculated using 2016 NDHS data to assess the burden of pneumonia attributable to HAP factors. RESULTS: The prevalence of childhood pneumonia decreased in Nepal between 2006 and 2016 and was higher among households using polluting cooking fuels. There was a higher risk of childhood pneumonia among children who lived in households with no separate kitchens in 2011 [Adjusted risk ratio (ARR) 1.40, 95% CI 1.01-1.97] and in 2016 (ARR 1.93, 95% CI 1.14-3.28). In 2016, the risk of children contracting pneumonia in households using polluting fuels was double (ARR 1.98, 95% CI 1.01-3.92) that of children from households using clean fuels. Based on the 2016 data, the PAF for pneumonia was calculated as 30.9% for not having a separate kitchen room and 39.8% for using polluting cooking fuel. DISCUSSION FOR PRACTICE: Although the occurrence of childhood pneumonia in Nepal has decreased, the level of its association with HAP remained high
Impaired antibody-mediated protection and defective IgA B cell memory in experimental infection of adults with respiratory syncytial virus
Rationale: Despite relative antigenic stability, respiratory syncytial virus (RSV) re-infects throughout life. After >40 years of research, no effective human vaccine exists and correlates of protection remain poorly defined. Most current vaccine candidates seek to induce high levels of RSV-specific serum neutralizing antibodies, which are associated with reduced RSV-related hospitalization rates in observational studies but may not actually prevent infection. Objectives: Characterize correlates of protection from infection and the generation of RSV-specific humoral memory to promote effective vaccine development. Methods: We inoculated 61 healthy adults with live RSV and studied protection from infection by serum and mucosal antibody. We analyzed RSV-specific peripheral blood plasmablast and memory B cell frequencies and antibody longevity. Measurements and Main Results: Despite moderately high levels of pre-existing serum antibody, 34 (56%) became infected, of whom 23 (68%) developed symptomatic colds. Prior RSV-specific nasal IgA correlated significantly more strongly with protection from PCR-confirmed infection than serum neutralizing antibody. Increases in virus-specific antibody titers were variable and transient in infected subjects, but correlated with plasmablasts that peaked around day 10. During convalescence, only IgG (and no IgA) RSV-specific memory B cells were detectable in peripheral blood. This contrasted with natural influenza infection, where virus-specific IgA memory B cells were readily recovered. Conclusions: This observed specific defect in IgA memory may partly explain RSV's ability to cause recurrent symptomatic infections. If so, vaccines able to induce durable RSV-specific IgA responses may be more protective than those generating systemic antibody alone
Impaired antibody-mediated protection and defective IgA B cell memory in experimental infection of adults with respiratory syncytial virus
Rationale: Despite relative antigenic stability, respiratory syncytial virus (RSV) re-infects throughout life. After >40 years of research, no effective human vaccine exists and correlates of protection remain poorly defined. Most current vaccine candidates seek to induce high levels of RSV-specific serum neutralizing antibodies, which are associated with reduced RSV-related hospitalization rates in observational studies but may not actually prevent infection. Objectives: Characterize correlates of protection from infection and the generation of RSV-specific humoral memory to promote effective vaccine development. Methods: We inoculated 61 healthy adults with live RSV and studied protection from infection by serum and mucosal antibody. We analyzed RSV-specific peripheral blood plasmablast and memory B cell frequencies and antibody longevity. Measurements and Main Results: Despite moderately high levels of pre-existing serum antibody, 34 (56%) became infected, of whom 23 (68%) developed symptomatic colds. Prior RSV-specific nasal IgA correlated significantly more strongly with protection from PCR-confirmed infection than serum neutralizing antibody. Increases in virus-specific antibody titers were variable and transient in infected subjects, but correlated with plasmablasts that peaked around day 10. During convalescence, only IgG (and no IgA) RSV-specific memory B cells were detectable in peripheral blood. This contrasted with natural influenza infection, where virus-specific IgA memory B cells were readily recovered. Conclusions: This observed specific defect in IgA memory may partly explain RSV's ability to cause recurrent symptomatic infections. If so, vaccines able to induce durable RSV-specific IgA responses may be more protective than those generating systemic antibody alone
Influenza hemagglutinin stem-fragment immunogen elicits broadly neutralizing antibodies and confers heterologous protection
Influenza hemagglutinin (HA) is the primary target of the humoral response during infection/vaccination. Current influenza vaccines typically fail to elicit/boost broadly neutralizing antibodies (bnAbs), thereby limiting their efficacy. Although several bnAbs bind to the conserved stem domain of HA, focusing the immune response to this conserved stem in the presence of the immunodominant, variable head domain of HA is challenging. We report the design of a thermotolerant, disulfide-free, and trimeric HA stem-fragment immunogen which mimics the native, prefusion conformation of HA and binds conformation specific bnAbs with high affinity. The immunogen elicited bnAbs that neutralized highly divergent group 1 (H1 and H5 subtypes) and 2 (H3 subtype) influenza virus strains in vitro. Stem immunogens designed from unmatched, highly drifted influenza strains conferred robust protection against a lethal heterologous A/Puerto Rico/8/34 virus challenge in vivo. Soluble, bacterial expression of such designed immunogens allows for rapid scale-up during pandemic outbreaks
Humoral and Cell-Mediated Immunity to Pandemic H1N1 Influenza in a Canadian Cohort One Year Post-Pandemic: Implications for Vaccination
We evaluated a cohort of Canadian donors for T cell and antibody responses against influenza A/California/7/2009 (pH1N1) at 8-10 months after the 2nd pandemic wave by flow cytometry and microneutralization assays. Memory CD8 T cell responses to pH1N1 were detectable in 58% (61/105) of donors. These responses were largely due to cross-reactive CD8 T cell epitopes as, for those donors tested, similar recall responses were obtained to A/California 2009 and A/PR8 1934 H1N1 Hviruses. Longitudinal analysis of a single infected individual showed only a small and transient increase in neutralizing antibody levels, but a robust CD8 T cell response that rose rapidly post symptom onset, peaking at 3 weeks, followed by a gradual decline to the baseline levels seen in a seroprevalence cohort post-pandemic. The magnitude of the influenza-specific CD8 T cell memory response at one year post-pandemic was similar in cases and controls as well as in vaccinated and unvaccinated donors, suggesting that any T cell boosting from infection was transient. Pandemic H1-specific antibodies were only detectable in approximately half of vaccinated donors. However, those who were vaccinated within a few months following infection had the highest persisting antibody titers, suggesting that vaccination shortly after influenza infection can boost or sustain antibody levels. For the most part the circulating influenza-specific T cell and serum antibody levels in the population at one year post-pandemic were not different between cases and controls, suggesting that natural infection does not lead to higher long term T cell and antibody responses in donors with pre-existing immunity to influenza. However, based on the responses of one longitudinal donor, it is possible for a small population of pre-existing cross-reactive memory CD8 T cells to expand rapidly following infection and this response may aid in viral clearance and contribute to a lessening of disease severity
Postnatal Zika virus infection is associated with persistent abnormalities in brain structure, function, and behavior in infant macaques
The Zika virus (ZIKV) epidemic is associated with fetal brain lesions and other serious birth defects classified as congenital ZIKV syndrome. Postnatal ZIKV infection in infants and children has been reported; however, data on brain anatomy, function, and behavioral outcomes following infection are absent. We show that postnatal ZIKV infection of infant rhesus macaques (RMs) results in persistent structural and functional alterations of the central nervous system compared to age-matched controls. We demonstrate ZIKV lymphoid tropism and neurotropism in infant RMs and histopathologic abnormalities in the peripheral and central nervous systems including inflammatory infiltrates, astrogliosis, and Wallerian degeneration. Structural and resting-state functional magnetic resonance imaging (MRI/rs-fMRI) show persistent enlargement of lateral ventricles, maturational changes in specific brain regions, and altered functional connectivity (FC) between brain areas involved in emotional behavior and arousal functions, including weakened amygdala-hippocampal connectivity in two of two ZIKV-infected infant RMs several months after clearance of ZIKV RNA from peripheral blood. ZIKV infection also results in distinct alterations in the species-typical emotional reactivity to acute stress, which were predicted by the weak amygdala-hippocampal FC. We demonstrate that postnatal ZIKV infection of infants in this model affects neurodevelopment, suggesting that long-term clinical monitoring of pediatric cases is warranted
Broadly cross-reactive antibodies dominate the human B cell response against 2009 pandemic H1N1 influenza virus infection
Although scarce after annual influenza vaccination, B cells producing antibodies capable of neutralizing multiple influenza strains are abundant in humans infected with pandemic 2009 H1N1 influenza
Initial antibodies binding to HIV-1 gp41 in acutely infected subjects are polyreactive and highly mutated
Many HIV-1 envelope-reactive antibodies shortly after HIV-1 transmission may arise from crow-reactive memory B cells previously stimulated by non-HIV-1 host or microbial antigen
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