Grill, Diane E.

ImportanceIndia’s goal of measles elimination remains unmet, as evidenced by significant recent outbreaks.ObjectiveTo identify seroprevalence rates among vaccinated children and to examine demographic factors that influence antibody responses.Design, Setting, and ParticipantsThis cross-sectional study included a highly vaccinated cohort of Indian children from the states of Kerala and Tamil Nadu between 2018 and 2023. Eligible children had received at least 2 doses of measles-containing vaccines; their mothers were recruited from various community settings, including local nursery and secondary schools, residential associations, and hospitals.ExposureMeasles-specific antibodies were quantified in serum samples.Main Outcomes and MeasuresMeasles-specific immunoglobulin G (IgG) and neutralizing antibodies were quantified in both children and mothers. Measles-specific IgM was also measured in children.ResultsThe total cohort comprised 684 children (median age, 9 years [range, 4-18 years]; 348 male [50.1%]) and 544 mothers. All children received at least 2 doses of measles-containing vaccines; 435 children (63.6%) received a third dose, and 7 (1.0%) received a fourth dose. Among the children, 621 (90.8%) had positive measles-specific IgG, and 623 (91.5%) had protective neutralizing antibodies titers, with a strong correlation between measles-specific IgG and neutralizing antibodies (r = 0.73; P < .001). Female children exhibited significantly higher titers of both measles-specific IgG and neutralizing antibodies compared with male children. While IgG and neutralizing antibody titers remained stable over time and were not associated with the number of vaccine doses in children, neutralizing antibody titers increased with age in mothers, likely due to repeated viral exposure. Notably, in 20 families with at least 2 children, differential measles-specific IgM profiles were observed between siblings despite high IgG and neutralizing antibody titers, suggesting ongoing breakthrough infections.Conclusions and RelevanceIn this cross-sectional study, substantial measles immunity gaps were found despite high vaccine coverage with evidence of breakthrough infections, posing significant challenges to India’s measles elimination efforts. These results underscore the urgent need to strengthen India’s immunization program and investigate the mechanisms driving suboptimal responses to measles vaccination; without addressing these immune response deficiencies, achieving measles elimination through increased vaccine coverage alone may remain unattainable in India.

Rubella is typically a mild viral illness, but it can lead to severe complications when contracted during pregnancy, such as pregnancy loss or developmental defects in the fetus (congenital rubella syndrome). Therefore, it is crucial to develop and maintain protective immunity in women of childbearing age. In this study, we assessed the transcriptional factors associated with rubella-specific immune outcomes (IgG binding antibody and avidity, neutralizing antibody, and memory B cell ELISpot response) following a third MMR vaccine dose in women of reproductive age to identify key factors/signatures impacting the immune response. We identified baseline (Day 0) and differentially expressed (Day 28–Day 0) genes associated with several RV-specific immune outcomes, including the transferrin receptor 2 (TFR2), which is an important factor regulating iron homeostasis and macrophage functional activity, and a close functional homolog of TFR1, the cellular receptor of the New World hemorrhagic fever arenaviruses. We also identified enriched KEGG pathways, “cell adhesion molecules”, “antigen processing and presentation”, “natural killer cell-mediated cytotoxicity”, and “immune network for IgA production”, relevant to immune response priming and immune activation to be associated with RV-specific immune outcomes. This study provides novel insights into potential biomarkers of rubella-specific immunity in women of childbearing age.

Abstract Background Antibody responses to MF59-adjuvanted (MF59Flu) and high-dose (HDFlu) influenza vaccines have been well-characterized in older adults, yet corresponding cellular immune response data remain limited. Methods Blood samples were collected from 106 MF59Flu recipients and 112 HDFlu recipients at 4 time points: before vaccination (day 0) and on days 1, 8, and 28 postvaccination. Antibody responses were assessed in serum samples using a hemagglutination inhibition assay. Eight proinflammatory cytokines and chemokines, including IFN-α2a, IFN-γ, IP-10, MCP-1, MIP-1α, IL-1β, IL-6, and IL-8, were quantified from peripheral blood mononuclear cells using a multiplex assay. Associations between cytokine/chemokine secretion levels and antibody responses were examined, along with the effect of sex, age, body mass index (BMI), and cytomegalovirus infection status. Results Age was positively correlated with IL-8 levels on day 1 (r = 0.24, P < .001) and the change in IL-8 levels from day 0 to day 1 (r = 0.16, P = .021). Notably, the change in IL-8 levels was negatively associated with day 28 hemagglutination inhibition titers (r = −0.15, P = .026). Causal mediation analysis demonstrated that IL-8 exerted significant causal mediation effects on antibody responses at both day 8 (P = .046) and day 28 (P = .0045). No significant effects of other cytokines and chemokines, vaccine type, sex, or BMI on antibody responses were observed. Conclusions Our findings underscore IL-8 as a potential mediator of antibody responses to influenza vaccination in older adults, suggesting that IL-8 inhibition could serve as a molecular intervention to improve antibody responses in this high-risk population.

BACKGROUND: Blood volume (BV) profiles vary markedly in patients with heart failure (HF), but how HF phenotypes and patient sex impact volume profiles remain to be explored. The aim of the study was to differentiate BV, plasma volume, and red blood cell mass profiles by phenotypes of preserved and reduced left ventricular ejection fractions and assess the impact of patient sex on profile heterogeneity. METHODS: Retrospective analysis of clinical and BV data was undertaken in patients with chronic New York Heart Association II–III heart failure. BV was quantitated using the nuclear medicine indicator-dilution methodology. RESULTS: A total of 530 BV analyses (360 HF with reduced ejection fraction and 170 HF with preserved ejection fraction) were identified in 395 unique patients. Absolute BV was greater in HF with reduced ejection fraction (6.7±1.8 versus 5.9±1.6 liters: P <0.001); however, large variability in frequency distribution of volume profiles was observed in both phenotypes (−22% deficit to +109% excess relative to normal volumes). HF with reduced ejection fraction was characterized by a higher prevalence of BV expansion ≥+25% of normal (39% versus 26%; P =0.003), and HF with preserved ejection fraction was characterized a by more frequent normal BV (42% versus 24%; P <0.001). Male sex in both phenotypes was associated with a larger absolute BV (7.0±1.6 versus 5.1±1.3 liters; P <0.001) and higher frequency of large BV and plasma volume expansions above normal (both P <0.001), while females in both phenotypes demonstrated a higher prevalence of normal BV and plasma volume (both P <0.001). CONCLUSIONS: Findings support significant differences in BV, plasma volume, and red blood cell mass profile distributions between heart failure phenotypes, driven in large part by sex-specific factors. This underscores the importance of identifying and distinguishing individual patient volume profiles to help guide volume management strategies.

Background: Disease progression in heart failure (HF) reflects multiple neurohormonal derangements resulting in adverse prognosis in the absence of overt clinical events. ST2 is up-regulated in response to cardiac injury/hemodynamic stress while modulating cardiac remodeling via inflammatory and apoptotic pathways. Accordingly, we evaluated changes in ST2 over time in conjunction with troponin T (cTnT) and BNP in ambulatory patients with chronic HF. Methods: A cohort of 191 NYHA class III-IV HF patients was prospectively evaluated with serial specimens collected every 3 months over a 2-year period. Primary end points were death or cardiac transplantation; secondary end points were combined death/transplantation and HF-related hospitalization. Plasma ST2 (Critical Diagnostics) was evaluated against contemporary cTnT (Roche 4th generation) and BNP (Shinogi) assays. Gender specific cut-points (>49.3 and >33.5 ng/mL for males and females, respectively) and a clinically defined optimal cut-point for ST2 (>35 ng/mL) were evaluated. Results: Time-dependent analyses (dichotomous and continuous variable) demonstrated ST2 gender specific cut-points were superior to a single ST2 cut-point and associated with an increased risk of death or transplantation (HR 4.8, 95% CI 2.8 to 8.3, p<0.0001) and combined death/transplantation/HF-hospitalization (HR 2.1, 95% CI 1.7 to 2.5, p<0.0001). Although cTnT remained the strongest predictor of death/transplantation (HR 3.2, 95% CI 1.6 to 5.4, p<0.0001) in multivariate analyses adjusted for cTnT and BNP, ST2 (HR 3.0, 95% CI 1.6 to 5.4, p=0.0003) added significantly to predictive accuracy. Furthermore, elevated ST2 was the only independent predictor of HF-hospitalization (HR 1.7, 95% CI 1.4 to 2.1, p<0.0001). In these models BNP was no longer significantly predictive (HR 1.2, 95% CI 0.7 to 2.2, p=0.58). Conclusions: Serial monitoring of changes in ST2 using gender specific cut-points adds to the diagnostic ability of cTnT in predicting mortality and/or transplantation in outpatients with chronic HF. ST2 uniquely predicts HF-hospitalization/death/transplantation, suggesting a serial monitoring strategy with cTnT and ST2 will optimize identification of HF patients at increased risk for events.

Abstract Aims To identify different red blood cell mass (RBCM) profiles, separate from haemoglobin concentrations, and their impact on blood volume expansion and clinical outcomes in chronic heart failure. Methods and results RBCM was measured at hospital discharge using standardized nuclear medicine indicator-dilution methodology in patients following diuretic treatment for clinical congestion. Individual RBCM phenotypes were prospectively identified and analysed for heart failure-related mortality or first rehospitalization over 1 year. Of 132 patients, 42 (32%) demonstrated normal RBCM, 36 (27%) RBCM deficit (true anaemia), and 54 (41%) RBCM excess (erythrocythemia). Dilutional ‘anaemia’ defined by haemoglobin &lt;12 g/dL with normal or an excess in RBCM with plasma volume expansion was identified in 37 (28%) patients. There were 61 composite outcome events, which included 38 deaths (29% of cohort) occurring over the 1 year follow-up period [14/36 (39%) in RBCM deficit, 12/42 (29%) in normal RBCM, and 12/54 (22%) in RBCM excess subgroups]. By Kaplan–Meier and multivariate analyses, RBCM excess was independently associated with the best event-free survival while RBCM deficit (true anaemia) the poorest outcomes; both compared with normal RBCM (P &lt; 0.001). Dilutional ‘anaemia’ demonstrated a lower risk compared with true anaemia (P = 0.03). Conclusions Markedly different RBCM profiles are identifiable among comparably compensated heart failure patients, and this variability carries significant implications for post-hospital outcomes. Novel to this analysis and in contrast to RBCM deficit is the independent association of RBCM excess with better event-free survival compared with normal RBCM. The distinction of RBCM profiles to guide risk stratification and individualized patient management strategies warrants further study.

Abstract Pre and post-licensure studies have supported the safety of the intranasally administered live, attenuated influenza vaccine (LAIV). The objective of this study was to measure changes to the nasal microbiome in subjects who received LAIV. We hypothesized that administration would result in only a transient alteration of the nasal microbiome. To test this hypothesis, we swabbed the anterior nares just before vaccination (Day 0), and on Day 7 and Day 28. We performed next-generation sequencing on amplified 16s rRNA genes. There was a significant increase in alpha diversity (Observed, CHAO, and ACE) from Days 0 to 7 (p = 0.02, 0.00, 0.01; respectively) and Days 0 to 28 (p = 0.05, 0.03, 0.05; respectively). When measuring differences in specific observed taxanomic units (OTUs), we identified a significant increase in Flavobacteriaceae and Enterobacteriaceae after vaccination. These data suggest that LAIV may increase the ability of these less abundant OTUs to establish a community niche and, therefore, could be clinically relevant. We have begun to investigate the second objective of this study, which is to correlate microbiome composition with mucosal immunity to influenza virus. To our knowledge, this is the first study to investigate LAIV-induced alterations to the human microbiome. These data may lead to a better understanding of the influences of the host microbiome on the response to vaccine, and perhaps infection.