Dataset Information

Assessment of indirect protection from maternal influenza immunization among non-vaccinated household family members in a randomized controlled trial in Sarlahi, Nepal.

ABSTRACT: Influenza is a significant cause of morbidity and mortality worldwide, and the World Health Organization highly recommends maternal vaccination during pregnancy. The indirect effect of maternal vaccination on other close contacts other than newborns is unknown. To evaluate this, we conducted a nested substudy between 2011 and 2012 of influenza and acute respiratory illness (ARI) among household members of pregnant women enrolled in a randomized placebo-controlled trial of antenatal influenza vaccination in the rural district of Sarlahi, Nepal. Women were assigned to receive influenza vaccination or placebo during pregnancy and then they and their household members were followed up to 6 months postpartum with weekly symptom surveillance and nasal swab collection. Swabs were tested by RT-PCR for influenza. Rates of laboratory-confirmed influenza and of ARI were compared between vaccine and placebo groups using generalized estimating equations with a Poisson link function. Overall, 1752 individuals in 520 households were eligible for inclusion. There were 82 laboratory-confirmed influenza illness episodes, for a rate of 7.0 per 100 person-years overall. Of the influenza strains able to be typed, 29 were influenza A, 40 were influenza B, and 6 were coinfections with influenza A and B. The rate did not differ significantly whether the household was in the vaccine or placebo group (rate ratio (RR) 1.37, 95% confidence interval (CI) 0.83-2.26). The rate of ARI was 28.5 per 100 person-years overall and did not differ by household group (RR 0.99, 95% CI 0.72-1.36). Influenza vaccination of pregnant women did not provide indirect protection of unvaccinated household members.

SUBMITTER: Newman KL

PROVIDER: S-EPMC7527778 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Assessment of indirect protection from maternal influenza immunization among non-vaccinated household family members in a randomized controlled trial in Sarlahi, Nepal.

Newman Kira L KL Stewart Laveta M LM Scott Emily M EM Tielsch James M JM Englund Janet A JA Khatry Subarna K SK Mullany Luke C LC LeClerq Steven C SC Shrestha Laxman L Kuypers Jane M JM Chu Helen Y HY Katz Joanne J

Vaccine 20200817 43

Influenza is a significant cause of morbidity and mortality worldwide, and the World Health Organization highly recommends maternal vaccination during pregnancy. The indirect effect of maternal vaccination on other close contacts other than newborns is unknown. To evaluate this, we conducted a nested substudy between 2011 and 2012 of influenza and acute respiratory illness (ARI) among household members of pregnant women enrolled in a randomized placebo-controlled trial of antenatal influenza vac ...[more]

PMID: 32814640

Similar Datasets

Project description:BackgroundThe intrapartum period is a time of high mortality risk for newborns and mothers. Numerous interventions exist to minimize risk during this period. Data on intervention coverage are needed for health system improvement. Maternal report of intrapartum interventions through surveys is the primary source of coverage data, but they may be invalid or unreliable.MethodsWe assessed the reliability of maternal report of delivery and immediate newborn care for a sample of home and health facility births in Sarlahi, Nepal. Mothers were visited as soon as possible following delivery (< 72 h) and asked to report circumstances of labor and delivery. A subset was revisited 1-24 months after delivery and asked to recall interventions received using standard household survey questions. We assessed the reliability of each indicator by comparing what mothers reported immediately after delivery against what they reported at the follow-up survey. We assessed potential variation in reliability of maternal report by characteristics of the mother, birth event, or intervention prevalence.ResultsOne thousand five hundred two mother/child pairs were included in the reliability study, with approximately half of births occurring at home. A higher proportion of women who delivered in facilities reported "don't know" when asked to recall specific interventions both initially and at follow-up. Most indicators had high observed percent agreement, but kappa values were below 0.4, indicating agreement was primarily due to chance. Only "received any injection during delivery" demonstrated high reliability among all births (kappa: 0.737). The reliability of maternal report was typically lower among women who delivered at a facility. There was no difference in reliability based on time since birth of the follow-up interview. We observed over-reporting of interventions at follow-up that were more common in the population and under-reporting of less common interventions.ConclusionsThis study reinforces previous findings that mothers are unable to report reliably on many interventions within the peripartum period. Household surveys which rely on maternal report, therefore, may not be an appropriate method for collecting data on coverage of many interventions during the peripartum period. This is particularly true among facility births, where many interventions may occur without the mother's full knowledge.

Project description:BackgroundThis costing study in Malawi is a first evaluation of a Maternal Influenza Immunization Program Costing Tool (Costing Tool) for maternal immunization. The tool was designed to help low- and middle-income countries plan for maternal influenza immunization programs that differ from infant vaccination programs because of differences in the target population and potential differences in delivery strategy or venue.MethodsThis analysis examines the incremental costs of a prospective seasonal maternal influenza immunization program that is added to a successful routine childhood immunization and antenatal care program. The Costing Tool estimates financial and economic costs for different vaccine delivery scenarios for each of the major components of the expanded immunization program.ResultsIn our base scenario, which specifies a donated single dose pre-filled vaccine formulation, the total financial cost of a program that would reach 2.3 million women is approximately $1.2 million over five years. The economic cost of the program, including the donated vaccine, is $10.4 million over the same period. The financial and economic costs per immunized pregnancy are $0.52 and $4.58, respectively. Other scenarios examine lower vaccine uptake, reaching 1.2 million women, and a vaccine purchased at $2.80 per dose with an alternative presentation.ConclusionThis study estimates the financial and economic costs associated with a prospective maternal influenza immunization program in a low-income country. In some scenarios, the incremental delivery cost of a maternal influenza immunization program may be as low as some estimates of childhood vaccination programs, assuming the routine childhood immunization and antenatal care systems are capable of serving as the platform for an additional vaccination program. However, purchasing influenza vaccines at the prices assumed in this analysis, instead of having them donated, is likely to be challenging for lower-income countries. This result should be considered as a starting point to understanding the costs of maternal immunization programs in low- and middle-income countries.

Project description:BACKGROUND:Identification of maternal and newborn illness and the decision-making and subsequent care-seeking patterns are poorly understood in Nepal. We aimed to characterize the process and factors influencing recognition of complications, the decision-making process, and care-seeking behavior among families and communities who experienced a maternal complication, death, neonatal illness, or death in a rural setting of Nepal. METHODS:Thirty-two event narratives (six maternal/newborn deaths each and 10 maternal/newborn illnesses each) were collected using in-depth interviews and small group interviews. We purposively sampled across specific illness and complication definitions, using data collected prospectively from a cohort of women and newborns followed from pregnancy through the first 28 days postpartum. The event narratives were coded and analyzed for common themes corresponding to three main domains of illness recognition, decision-making, and care-seeking; detailed event timelines were created for each. RESULTS:While signs were typically recognized early, delays in perceiving the severity of illness compromised prompt care-seeking in both maternal and newborn cases. Further, care was often sought initially from informal health providers such as traditional birth attendants, traditional healers, and village doctors. Key decision-makers were usually female family members; husbands played limited roles in decisions related to care-seeking, with broader family involvement in decision-making for newborns. Barriers to seeking care at any type of health facility included transport problems, lack of money, night-time illness events, low perceived severity, and distance to facility. Facility care was often sought only after referral or following treatment failure from an informal provider and private facilities were sought for newborn care. Respondents characterized government facility-based care as low quality and reported staff rudeness and drug type and/or supply stock shortages. CONCLUSION:Delaying the decision to seek skilled care was common in both newborn and maternal cases. Among maternal cases, delays in receiving appropriate care when at a facility were also seen. Improved recognition of danger signs and increased demand for skilled care, motivated through community level interventions and health worker mobilization, needs to be encouraged. Engaging informal providers through training in improved danger sign identification and prompt referral, especially for newborn illnesses, is recommended.

Project description:BackgroundInfants are at greatest risk for pertussis morbidity and mortality. Maternal vaccination during pregnancy has been shown to prevent pertussis in young infants in high- and middle-income countries. However, data on the levels of maternal pertussis antibodies and the efficiency of transplacental transfer in low-income South Asian settings are limited.ObjectiveTo estimate the prevalence of maternal pertussis antibodies and the efficiency of transplacental transfer in rural southern Nepal.Design/methodsPaired maternal-infant blood samples were collected from a subsample of participants in a randomized, controlled trial of maternal influenza immunization (n=291 pairs). Sera were tested by enzyme-linked immunosorbent assays for pertussis toxin, filamentous hemagglutinin, pertactin, and fimbriae. Maternal and infant pertussis antibody levels and transplacental transfer efficiency were determined and potential factors associated with both were assessed.ResultsElevated maternal antibodies to pertussis toxin, suggesting recent pertussis infection, were rarely detected (4%, tested n=305). However, paired maternal-cord sera were highly correlated across all antibodies; transplacental antibody transfer ratios for pertussis toxin were 1.14 (n=291, 95% CI 1.07-1.20); filamentous hemagglutinin 1.10 (n=120, 95% CI: 1.01-1.20); fimbriae 2/3 1.05 (n=120, 95% CI: 0.96-1.15) and pertactin 0.96 (n=289, 95% CI: 0.91-1.00). Older gestational age was associated with increased pertussis toxin and decreased fimbriae 2/3 antibody transport.ConclusionsA low prevalence of maternal antibody to all four pertussis antigens was noted in Nepal, but transplacental antibody transfer was efficient. No consistent demographic factors were associated with elevated maternal antibody levels or efficiency of transplacental transfer. If an increase in infant pertussis disease burden was detected in this population, maternal immunization could be an effective intervention to prevent disease in early infancy.

Project description:BackgroundRabies is a vaccine-preventable neglected tropical viral zoonosis. It occurs worldwide, creating a very heavy burden in many developing countries, including Nepal. Dogs are the principle vector for the transmission of this disease in urban areas. Vaccination is the most important preventive measure in areas where dogs are the principle source of infection. This study was conducted with the aim of detecting virus-neutralising antibodies and associated factors against rabies in vaccinated household dogs of Kathmandu valley.MethodsBlood samples were collected from 110 vaccinated pet dogs in Kathmandu, Bhaktapur, and Lalitpur districts of Nepal. The samples were taken to the laboratory of the National Zoonosis and Food Hygiene Research Center where serum was separated. An indirect immune-enzymatic assay (PlateliaTM Rabies II kit ad usum Veterinarium, Biorad, China) was used for the detection of rabies virus anti-glycoprotein antibodies in the dog serum samples following the manufacturer's recommendations and instructions. Optical density values for unknown samples were compared with the positive sera titers in quantification tests obtained after a direct reading on the standard curve. Results were expressed as equivalent units per ml (EU/ml).FindingsOf the total samples, 89.09% exceeded the required seroconversion level (? 0.5 EU/ml); another 9.09% did not reach the seroconversion level (0.125-0.5 EU/ml); and 1.81% had undetectable seroconversion levels (<0.125 EU/ml) suggesting that the animal had not seroconverted according to the PLATELIA™ RABIES II test. Only one factor, the condition under which the dog was kept, was significantly associated with the antibody titer level. No association was found for any of the other factors included in the study.InterpretationVaccination is the most effective measure for prevention and control of rabies. The locally manufactured brand of vaccine, which is available in Nepal, is potent enough to generate a sufficient amount of protective antibodies, equal to international brands.

Dataset Information

Assessment of indirect protection from maternal influenza immunization among non-vaccinated household family members in a randomized controlled trial in Sarlahi, Nepal.

Publications

Assessment of indirect protection from maternal influenza immunization among non-vaccinated household family members in a randomized controlled trial in Sarlahi, Nepal.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets