In two ongoing trials in Vietnam and Belgium (clinicaltrials.gov NCT01698346) we vaccinated pregnant women with a tetanus, diphtheria, acellular pertussis (Tdap) vaccine. ...RAI of anti-PT antibodies ...has been investigated in very few studies.
There are few reliable estimates of the half-lives of maternal antibodies to the antigens found in the primary series vaccines. We aimed to calculate the half-lives of passively acquired diphtheria, ...tetanus and pertussis (DTP) antibodies in infants. We aimed to determine whether decay rates varied according to country, maternal age, gestational age, birthweight, World Bank income classifications, or vaccine received by the mother during pregnancy.
De-identified data from infants born to women taking part in 10 studies, in 9 countries (UK, Belgium, Thailand, Vietnam, Canada, Pakistan, USA, Guatemala and the Netherlands) were combined in an individual participant data meta-analysis. Blood samples were taken at two timepoints before any DTP-containing vaccines were received by the infant: at birth and at 2-months of age. Decay rates for each antigen were log2-transformed and a mixed effects model was applied. Half-lives were calculated by taking the reciprocal of the absolute value of the mean decay rates.
Data from 1426 mother-infant pairs were included in the analysis. The half-lives of the 6 antigen-specific maternal antibodies of interest were similar, with point estimates ranging from 28.7 (95% CI: 24.4 – 35) days for tetanus toxoid antibodies to 35.1 (95% CI: 30.7 – 41.1) days for pertactin antibodies. The decay of maternal antibodies did not significantly differ by maternal age, gestational age, birthweight, maternal vaccination status or type of vaccine administered.
Maternal antibodies decay at different rates for the different antigens; however, the magnitude of the difference is small. Decay rates are not modified by key demographic or vaccine characteristics.
Vietnam is implementing hepatitis B (HBV) birth dose (BD) vaccination since 2003 but coverage remains low, especially in the Mekong River Delta. This study aimed to determine the coverage of the HBV ...BD vaccination, to identify socio-demographic factors influencing HBV BD, and to assess reasons for non-immunization of neonates.
A cross-sectional survey was conducted in 2015–2016. Mothers from 526 children aged 6–11 months living in 3 provinces in the Mekong River Delta - representing respectively urban, rural and remote area - were interviewed at home and infant vaccination documents were checked. The three-stage sampling method was adapted from WHO 30-cluster sampling. Predictors of HBV BD administration were identified with multiple regression analysis.
The overall HBV BD coverage (within 24 h) was 46.6% (compared to 44.5% for BCG) and was significantly higher in remote or rural than in urban area (OR 1.87 and 3.36, respectively), and in children whose father had a higher educational level (OR 2.76; 2.29 and 1.86, respectively, for master degree, bachelor and secondary school) as compared to a lower level. Main reasons for not having received HBV BD mentioned by parents were vaccines not offered by health care workers (53.0%), and illness of the infant (27.2%).
Although Vietnam started HBV BD vaccination more than 10 years ago, the coverage and timeliness need to improve to reach WHO targets (95% within 24 h after birth). Better training and information of health care workers, and better protocols ensuring timely HBV BD could address these vaccine administration thresholds.
The role of T cell receptor (TCR) diversity in infectious disease susceptibility is not well understood. We use a systems immunology approach on three cohorts of herpes zoster (HZ) patients and ...controls to investigate whether TCR diversity against varicella-zoster virus (VZV) influences the risk of HZ. We show that CD4+ T cell TCR diversity against VZV glycoprotein E (gE) and immediate early 63 protein (IE63) after 1-week culture is more restricted in HZ patients. Single-cell RNA and TCR sequencing of VZV-specific T cells shows that T cell activation pathways are significantly decreased after stimulation with VZV peptides in convalescent HZ patients. TCR clustering indicates that TCRs from HZ patients co-cluster more often together than TCRs from controls. Collectively, our results suggest that not only lower VZV-specific TCR diversity but also reduced functional TCR affinity for VZV-specific proteins in HZ patients leads to lower T cell activation and consequently affects the susceptibility for viral reactivation.
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•T cell phenotypes did not significantly differ between HZ patients and controls•CD4+ TCR diversity against VZV gE and IE63 after culture was broader in controls•T cell activation pathways after VZV peptide stimulation were lower in HZ patients•TCRs from HZ patients co-clustered more often together than TCRs from controls
Boeren et al. demonstrate that susceptibility for shingles, caused by varicella-zoster virus (VZV) reactivation, correlates with reduced T cell receptor (TCR) diversity against several VZV proteins. Their results indicate that reduced T cell activation correlates with reduced affinity between VZV proteins and the VZV-specific TCR repertoire in shingles patients.
Methods Using data from a cohort of pregnant women whose offspring were followed up to 1 year (n=350), we evaluated the impact of fish consumption during third trimester on the incidence of atopic ...manifestations in 65 maternal-infants pairs.
The varicella-zoster virus (VZV) infects over 95% of the population. VZV reactivation causes herpes zoster (HZ), known as shingles, primarily affecting the elderly and immunocompromised individuals. ...However, HZ can also occur in otherwise healthy individuals. We analyzed the immune signature and risk profile in HZ patients using a genome-wide association study across different UK Biobank HZ cohorts. Additionally, we conducted one of the largest HZ HLA association studies to date, coupled with transcriptomic analysis of pathways underlying HZ susceptibility. Our findings highlight the significance of the MHC locus for HZ development, identifying five protective and four risk HLA alleles. This demonstrates that HZ susceptibility is largely governed by variations in the MHC. Furthermore, functional analyses revealed the upregulation of type I interferon and adaptive immune responses. These findings provide fresh molecular insights into the pathophysiology and the activation of innate and adaptive immune responses triggered by symptomatic VZV reactivation.
Do vaccines save lives? Yes they do Lernout, Tinne; Theeten, Heidi; Leuridan, Elke ...
Acta medica portuguesa,
03/2014, Letnik:
27, Številka:
2
Journal Article
Odprti dostop
Since their introduction and widespread use, vaccines have been very successful in reducing morbidity and mortality of the diseases they target, at an individual level and through herd immunity. The ...impact on the mortality has been rapid and easy to measure for some diseases, such as diphtheria, pertussis and measles. For other diseases, including hepatitis B and human papillomavirus infections, deaths averted occur many years after vaccination, and it takes years until the full potential of the vaccine can be established. Finally, in middle and high income countries, the impact of vaccination against some diseases, like invasive pneumococcal disease and rotavirus gastro-enteritis, is measured by decrease in incidence of the disease and reduction in hospitalization rather than impact on mortality. But in the countries with the highest incidence of these diseases, mortality remains high due to low availability of these vaccines, and millions of deaths could be averted by optimal use of vaccines in these regions. Major challenges for vaccination programmes are to maintain and strengthen trust in the benefits of vaccination and adapt immunization schedules according to the changing epidemiological landscape.
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