Maternal Measles Antibodies Research Articles

Comparison of measles plaque reduction neutralization test (PRNT) and measles virus-specific IgG ELISA for assessment of immunogenicity of measles-mumps-rubella vaccination at 5–7 months of age and maternal measles antibodies

BackgroundAssessing the risk of measles outbreaks and identifying the susceptible parts of the population is essential to timely intervention. Infants between 6–12 months are increasingly susceptible to measles but evaluating the performance of high throughput enzyme immunoassays (ELISAs) in infants < 9 months of age is lacking. MethodsA commercially available ELISA kit (Creative Diagnostics, DEIA359) for estimating measles seroprotection was evaluated in infants 5–7 months of age. In an immunogenicity substudy in the Danish MMR trial conducted between 2019–2021, infants (and mothers at baseline) were sampled before and one month after measles-mumps-rubella vaccination (MMR) or placebo as well as one month after routine MMR at 15 months. Measles IgG ELISA was compared to the gold standard but labor-intensive measles plaque reduction neutralization test (PRNT) by Pearson and Spearman correlations and by estimating sensitivity, specificity, and positive and negative predictive values (PPV and NPV). FindingsMeasles IgG levels compared to PRNT antibodies had a Pearson’s correlation coefficient between 0.10–0.24. Seroprotection rates measured by ELISA in young infants were 10–14% lower than measured by PRNT. The sensitivity of the ELISA to detect serological protection compared to PRNT in the infant population differed markedly across sampling time points and was 14%, 40%, and 92% at baseline, post-intervention, and post-routine MMR, whereas the specificity was 99%, 93%, and 43%, respectively. The PPV and NPV were 68% and 87% in infants at baseline. InterpretationThe correlation between measles IgG and PRNT antibodies was low. Seroprotection was underestimated using ELISA. High-accuracy tests are needed to avoid misclassifications and practices that lead to primary or secondary vaccine failure or retention of vaccination in outbreak settings. Baseline PPV and NPV suggested some applicability of ELISA in predicting serological protection in this age group. However, PRNT may be the only accurate estimator of serological protection in young infants.

Waning of maternal antibody against measles virus in Shufu, China

ABSTRACT Background: As measles vaccination coverage has increased, measles infection has shifted to the population of infants. We conducted a follow-up seroepidemiological study among mothers and their infants to evaluate measles seroprevalence and the persistence of maternal measles antibody in Shufu, Kashgar from 2018 to 2020. Methods: Maternal venous blood and cord blood was obtained among mothers and their infants at 0, 3, 5, 8, 9, and 12 months of age. An enzyme-linked immunosorbent assay was used for quantitative measurement of measles antibodies. We analyzed the correlation between maternal and neonatal measles antibodies, and antibodies persistence after infants were born. Results: The overall neonatal maternal ratio was 2.38 (95%CI: 2.05–2.71). The measles antibodies for mothers and newborns were 438.93 IU/mL (95%CI: 409.47–470.51 IU/mL) and 440.10 IU/mL (95%CI: 410.82–471.48 IU/mL), respectively. Neonatal measles antibodies were dropping after birth and then beginning to increase starting at 8 months of age. Conclusions: Infant measles antibody levels progressively declined after birth regardless of maternal measles antibody levels. Efforts should be carried out to eliminate measles.

Effect of early two-dose measles vaccination on childhood mortality and modification by maternal measles antibody in Guinea-Bissau, West Africa: A single-centre open-label randomised controlled trial.

SummaryBackgroundEarly 2-dose measles vaccine (MV) at 4 and 9 months of age vs. the WHO strategy of MV at 9 months of age reduced all-cause child mortality in a previous trial. We aimed to test two hypotheses: 1) a 2-dose strategy reduces child mortality between 4 and 60 months of age by 30%; 2) receiving early MV at 4 months in the presence versus absence of maternal measles antibodies (MatAb) reduces child mortality by 35%.MethodsSingle-centre open-label community-based randomised controlled trial in Guinea-Bissau, with 2:1 block-randomisation by sex to a 2-dose (4 + 9 months) vs. 1-dose (9 months) MV strategy. Healthy children were eligible 4 weeks after the 3rd diphtheria-tetanus-pertussis-containing vaccine. Before randomisation a blood sample was collected to determine MatAb level. The primary outcome was all-cause mortality. Hazard ratios (HR) were derived from Cox regression in the per protocol population. We tested for interactions with national campaigns with oral polio vaccine (C-OPV). Trial registration: NCT01486355.FindingsBetween August 2011-April 17th 2015, 6,636 children were enroled, 6,598[n2-dose=4,397; n1-dose=2,201] were included in the analysis of the primary outcome, The HR(2-dose/1-dose) between 4 and 60 months was 1.38 (95%CI: 0.92–2.06) [deaths: n2-dose=90; n1-dose=33]. Before the 9-month MV and the HR(1-dose/no dose) was 0.94 (0.45–1.96) [deaths: n2-dose=21; n1-dose=11]. The HR(2-dose/1-dose) was 0.81 (0.29–2.22) for children, who received no C-OPV [deaths/children: n2-dose=10/2,801; n1-dose=6/1,365], and 4.73 (1.44–15.6) for children, who received C-OPV before and after enrolment (p for interaction=0.027) [deaths/children: n2-dose=27/1,602; n1-dose=3/837]. In the 2-dose group receiving early MV at 4 months, mortality was 50% (20–68%) lower for those vaccinated in the presence of MatAb vs. the absence of MatAb [deaths/children: nMatAb=51/3,132; nnoMatAb=31/1,028].InterpretationThe main result contrasts with previous findings but may, though based on a small number of events, be explained by frequent OPV campaigns that reduced the mortality rate, but apparently interacted negatively with early MV. The beneficial non-specific effects of MV in the presence of MatAb should be investigated further.Funding10.13039/501100000781ERC, Danish National Research Foundation, the Danish Council for Development Research, Ministry of Foreign Affairs, Novo Nordisk Foundation, European Union and the Lundbeck Foundation.

Measles susceptibility in maternal-infant dyads—Bamako, Mali

Measles is endemic in Africa; measles mortality is highest among infants. Infant measles antibody titer at birth is related to maternal immune status. Older mothers are likelier to have had measles infection, which provides higher antibody titers than vaccine-induced immunity. We investigated the relationship between maternal age and measles susceptibility in mother-infant pairs in Mali through six months of infancy.We measured serum measles antibodies in 340 mother-infant pairs by plaque reduction neutralization test (PRNT) and calculated the proportion of mothers with protective titers (>120 mIU/mL) at delivery and the proportion of infants with protective titers at birth, and at three and six months of age. We explored associations between maternal age and measles antibodies in mothers and infants at the timepoints noted.Ten percent of Malian newborns were susceptible to measles; by six months nearly all were. Maternal and infant antibody titers were highly correlated. At delivery, 11% of mothers and 10% of newborns were susceptible to measles. By three and six months, infant susceptibility increased to 72% and 98%, respectively. Infants born to younger mothers were most susceptible at birth and three months. Time to susceptibility was 6.6 weeks in infants born to mothers with measles titer >120–<430 mIU/mL versus 15.4 weeks when mothers had titers ≥430 mIU/mL.Maternal and newborn seroprotective status were positively correlated. Improved strategies are needed to protect susceptible infants from measles infection and death. Increasing measles immunization coverage in vaccine eligible populations, including nonimmune reproductive-aged women and older children should be considered.

Measles Neutralization Antibodies and Some Related Factors in Women of Reproductive-age in Hanoi, Vietnam

Aims: Our study aimed to determine neutralization antibodies against measles virus and some related factors in women of childbearing-age from 18 to 30 years old, in Hanoi, Vietnam.&#x0D; Methodology: In 2018, a cross-sectional study was conducted on 1,235 childbearing-age women from 18-30 years old in Bavi district, Hanoi, Vietnam. The study participants were interviewed by using a structured questionnaire which included demographic information, and history of measles. The measles neutralization antibodies (MNA) of these participants were quantified by a plaque reduction neutralization test (PRNT). The data were analyzed using the Epidata 3.1 and Stata 14.2 software.&#x0D; Results: The results showed that only 58.5% had MNA at sufficient protective levels (≥120mIU/ml), up to 12.5% were negative for MNA, and 358 women (29%) had MNA at insufficient protective levels. In addition, we found that the participants’ working as public employees, having two children, and being ≥ 25 years of age were all positively associated with the sufficient protective antibody levels (P&lt;0.05). A weak positive correlation between age and MNA titers was determined (r= 0.26).&#x0D; Conclusion: Approximately half (41.5%) of the women of childbearing age in this study did not have sufficient protective antibodies against measles virus. The study results suggest that it is necessary to boost measles vaccine to prevent the sporadic measles infection in women of childbearing age in Hanoi and to quantify the dynamics of maternal measles antibody levels in infants born from these women, so as to provide evidences to control measles incidence in children up to 9 months of age in the future.

Measles Vaccination in the Presence of Maternal Measles Antibody Reduces All-Cause Child Mortality - A Planned Cohort Study Nested in a Randomised Trial

Background: Several smaller studies suggested that measles vaccination (MV) in the presence of maternal measles antibody (MatAb) reduces all-cause mortality. We tested the hypothesis that children receiving early MV at 4 months in the presence of MatAb would have 35% lower mortality than children receiving MV at 4 months with no detectable MatAb. We further hypothesised that among children, who did not receive early MV, there would be no difference in mortality between those with and without MatAb. Methods: The study was an observational study nested within a randomised controlled trial (RCT) of early MV, carried out in Guinea-Bissau from 2011-2019. The RCT compared the mortality between 4 and 60 months of age for children randomised 2:1 to two doses of MV at 4 and 9 months of age or to only one dose of MV at 9 months of age. At enrolment in the RCT, a blood sample was collected from all children. A multiplex immunoassay was used to determine the measles MatAb level; as control exposures, levels of varicella, mumps and rubella antibody were assessed. We assessed overall mortality as a function of randomisation group and presence of MatAb in Cox proportional hazards models. Results: 6,598 children were enrolled in the RCT, 6,239 (95%) had a valid enrolment blood sample. In children receiving early MV at enrolment, mortality was 50% (95% CI: 20-68%) lower for those vaccinated in the presence of MatAb (n=3132; 51 died) compared with those vaccinated in the presence of no MatAb (n=1028, 31 died). There was no beneficial effect of having MatAb in children who did not receive early MV (test of interaction, p=0.045). The result was specific for measles antibody; no effect was found for varicella, mumps or rubella antibodies. In a meta-analysis of five available studies, MV in the presence of MatAb was consistently associated with lower mortality compared with MV in the absence of MatAb, the combined meta-estimate indicating 55% (35-68%) lower mortality. Interpretation: The results support the previous findings that MV in the presence of maternal antibody enhances the beneficial effects of MV on child survival. Earlier measles vaccination should be considered. Further research is needed to examine whether it is beneficial to vaccinate women of fertile age to transfer higher level of maternal antibodies to their children. Trial Registration (for the RCT): NCT01486355 Funding: The RCT was funded by an ERC Starting Grant to Christine S Benn (ERC-2009-StG-243149) and by a “Center of Excellence” grant from the Danish National Research Foundation (DNRF108). The work on non-specific effects of vaccines has been supported by the Danish Council for Development Research, Ministry of Foreign Affairs, Denmark [grant number 104.Dan.8.f.], Novo Nordisk Foundation and European Union FP7 support for OPTIMUNISE (grant: Health-F3-2011-261375). The funding agencies had no role in the study design, data collection, data analysis, data interpretation, or the writing of the report. Declaration of Interests: Authors declare no competing interests. Ethics Approval Statement: The protocol was approved by the National Ethical Committee in Guinea-Bissau and given consultative approval by the Danish Central Ethical Committee

Prevalence of Maternal Measles Antibody and Its Associated Factors among Infants in Coastal Karnataka, India.

Background:The current recommendation in India to commence first dose of measles immunization is at 9 months of age. The effectiveness of measles vaccination is greatly impacted by the level of maternal measles antibody (MMA) during infancy.Objectives:To find the prevalence of MMA and to study the maternal and infant factors associated with persistence of MMA among the infants in a Indian rural community.Methodology:Dried blood spot sample was collected before vaccination among infants aged 9 months and above when they came for first dose of measles vaccine to assess measles-specific maternal IgG antibody titers by enzyme immunoassay. Maternal and child factors influencing persistence of MMA were collected by interviewing the mothers. Association between various factors affecting seropositivity was tested using univariate logistic regression analysis and strength of association is reported as risk ratio with 95% confidence interval.Results:Based on the qualitative estimation among all the recruited children (250) in the study, 4 (1.6%) infants showed the presence of MMA whereas 25 (10%) of children had MMA on quantitative estimation. The effect of maternal factors, child nutrition, and sociodemographic factors on the presence of MMA was not found to be statistically significant.Conclusion:The prevalence of persistent MMA (IgG titer ≥200 mIU/ml) among the infants aged 9–12 months was 10%. The choice of vaccinating infants at the end of 9 months for the first dose of measles vaccine is justified as the remaining (90%) of infants were susceptible for measles infection at this age.

Maternal Measles Antibodies and Their Influence on All-cause Mortality Following Measles Vaccination: An Alternative to Measure Very Low Maternal Antibody Levels.

It was previously shown by hemagglutination inhibition that measles vaccination in the presence of maternal measles antibodies was associated with reduced all-cause mortality. We confirmed this serological association using a multiplexed immunoassay as a sensitive alternative and estimated a threshold concentration (28.7 mIU/mL) that correlates with lower all-cause mortality (P = .02).

The correlation between newborns and pregnant women measles antibody level and the regularity of the change of newborns antibody with time

Objective To analyze the correlation between newborn and mother's measles antibody level and the regularity of the change of newborn antibody with time. Methods Prenatal venous blood and newborns′ umbilical cord blood of 127 pregnant women in the Eighth People's Hospital of Qingdao were collected, and venous blood of 3-month-old in 79 cases, 6-month-old in 72 cases and 9-month-old in 57 cases of newborns were followed up.The level of measles IgG antibody was detected by enzyme-linked immunosorbent assay. Results The geometric mean concentration of the maternal measles antibody was (639.56±3.15)mIU/mL, which was significantly lower than that of the neonatal blood antibody concentration [(1 102.46±2.86)mIU/mL](P<0.05). The geometric means of neonatal measles antibody in 3, 6, 9 months old newborns were (159.95±3.25)mIU/mL, (126.35±4.06)mIU/mL, (113.04±4.32)mIU/mL respectively, which were significantly lower than those of the newborn at birth(all P<0.05). With the increase of the age, the positive rate and protection rate of the newborn all decreased significantly(all P<0.05). Using trend Chi square test, it was found that the level of measles antibody increased with the increase of measles antibody level(χ2=9.46, P<0.05). Pearson correlation analysis showed that the logarithmic level of maternal blood antibody was closely correlated with the umbilical cord blood(r=0.78), 3-month-old(r=0.54), 6-month-old(r=0.47), 9-month-old(r=0.53) blood antibody logarithm level(all P<0.05). Univariate analysis showed that the geometric mean of neonatal measles antibody was significantly correlated with neonatal sex, delivery mode, gestational age, birth weight and maternal age(all P<0.01). Conclusion With the increase of time, the measles antibody gradually attenuates, and the level of antibody is closely correlated with the level of maternal antibody.Therefore, we should actively implement measles vaccination for women of childbearing age, and adopt a way to improve maternal antibody concentration to increase the concentration of neonatal measles antibody, so as to prevent or reduce measles in infants. Key words: Measles; Antibodies; Newborns; Mothers

Maternal measles antibodies and infant susceptibility in Chandigarh, India

Background: Measles continues to be endemically transmitted in many parts of the world including India. The single dose measles vaccine was first introduced in India in 1985 with recommendation for a second dose added in 2010. Consequently, most mothers and women of reproductive age in India have not received the two recommended doses of vaccine. This study seeks to understand the impact of the changing dynamic of natural measles infection versus vaccination on maternal and infant measles antibody levels. We compare antibodies in infants and their mothers at the time of the birth of their child and through the infant's first year of life. Methods & Materials: Pregnant mothers were systematically selected into this population-based cohort study in Chandigarh, India. Serum samples were tested for anti-measles IgG antibodies from mothers at the time of their infant's birth, and from infants at birth, 3, 6, 9, and 12 months. A positive measles reading (indicating immunity and protection from subsequent infection) was defined as > 12 U/ml. The study is ongoing. Results: Of the 306 mother-infant dyads enrolled in the study, the mean maternal IgG titer of infants who were IgG positive was 97.0 U/ml (SD ± 65.0) and the mean maternal IgG titer of infants who were IgG negative was 18.7 U/ml (SD ± 29.5). Mean antibody tiers in mothers were also higher for mothers whose infants tested IgG positive at three months, 142.8 U/ml (SD ± 60.1), compared to those testing IgG negative 65.7 U/ml (SD ± 56.6). Infant antibody titers at birth were significantly greater among infants whose mothers had reported measles infection 145.6 U/ml (SD ± 72.4) than among mothers who were vaccinated 102.1 U/ml (SD ± 63.2) (P = 0.01). Conclusion: Greater measles antibody titers in mothers resulted in infants retaining immunity at birth and at 3 months. Moreover, mothers who previously had disease gave birth to infants with higher titers than infants born to vaccinated mothers. Programs targeting vaccination of young adult women of reproductive age could bolster population level immunity and also enable mothers to pass on higher levels of protective antibodies to their infants.

Prevalence of maternal measles, rubella, mumps and varicella antibodies in the first six months of life

The protection of infants against infections during the first few months of life is provided mainly by maternal antibodies. The presence of maternal antibodies can decrease vaccine efficacy. The waning time of maternal antibodies shows variations therefore seroepidemiological studies are important for the development of vaccination schedules. Some recent studies showed that the maternal measles antibodies may disappear around 3 months of age especially in infants born from mothers who were vaccinated. There are few cross-sectional studies from Turkey evaluating the maternal antibody levels of infants against measles in recent years. The aim of this prospective, multicentre study is to evaluate the seropositivity of measles, rubella, mumps, and varicella in mothers and their infants at 1 and 6 months after birth. The study was carried out at the Social Pediatrics Units of two university hospitals, a private hospital and a state hospital. The exclusion criteria were known impaired immune system or immune deficiency disorder in mother or child, preterm delivery (< 37 gestational week), administration of immunoglobulins or any blood products before admission or during the follow-up period, and history of vaccination or exposure to one of these diseases during the study period. The final analysis encompassed 209 mother-infant pairs. Blood samples were collected 1 month after birth from mothers and 1 and 6 months after birth from their babies. Antibody levels were determined by ELISA (Enzyme-Linked ImmunoSorbent Assay) method. Information on the socio-economic and demographic characteristics of the families were collected by a face-to-face questionnaire. Seropositivity was found as 95.7%, 92.8%, 92.8% and 96.7% for measles, mumps, rubella and varicella (MMRV) respectively. Majority of infants lost maternal antibodies at 6 months of age. Of all 6 month-old infants 25% were seropositive for measles,14.6% for mumps, 23.2% for rubella and 17.1% for varicella. The proportion of seropositive infants born from seropositive mothers was higher than those born from seronegative mothers for all four diseases. This difference was statistically significant only at 1 month of age (p= 0.001). Our study showed that maternal antibodies against MMRV decreased rapidly by 6 months of age therefore necessary measures should be taken to close this gap between the loss of maternal protection and the vaccination of infants for MMRV. As the epidemiology of the diseases changes in time, it is important to carry out such studies with large series in different countries and settings. Important results were determined in our study within this respect.

Declining Maternally-Derived Measles Antibodies in Infants and Nursing Mothers in Nigeria: A Review

Measles, also reffered to as rubeolais an endemic respiratory disease caused by a virus. It is a highly contagious infection which typically begins with a mild to moderate fever, often accompanied by a persistent cough, runny nose, conjunctivitis and sore throat. Today, despite the availability of a safe, effective and relatively inexpensive vaccine for more than 40 years, measles still kills more than any other vaccines preventable disease among children. In Pregnant women, IgG immunoglobulin antibody is produced and crosses the placenta to developing fetus’ blood circulation; thereby conferring primary protection against infections in the early life of newborns. The presence or absence of Maternal Measles Antibody (MMA) in infants is therefore a factor to be considered in immunization of infants against measles. In Nigeria, the recommended age for routine measles vaccination for infants is at 9 month of age. However, it has been severely reported that the present-day civilized mothers are more measles vaccine-immuned contrary to been natural measles virus-immuned and as such, produce low titer anti-measles virus antibody which consequently decays or clears from their respective infants earlier than 9 months of age when measles vaccine is routinely administered. Early immunization against measles may potentially minimize the duration of the period between the loss of maternal antibodies transferred via the placenta and the administration of the recommended measles vaccination for infants, hence the need for the re-evaluation of the measles immunization schedule. Keywords: Vaccination; Maternal Measles Antibody; Infant, Virus;

Measles outbreaks in the Kyeongin area of the Republic of Korea, 2013-2014: A single-center experience in a country of measles elimination.

To identify the source of infection and determine the clinical features and laboratory finding of measles infection. In 27 measles patients, except for 3 adult patients, the rest of 24 pediatric measles cases were analyzed with regard to age, sex, immunization status, transmission routes and molecular genotyping of measles virus. Eighteen measles patients who admitted in isolation ward were set apart to investigate clinical findings and its correlation with laboratory characteristics. Retrospective analysis of cases was conducted in this study. Of the 24 pediatric patients, 23 (95.8%) had not received any measles-containing vaccine (MCV). Sixteen of the patients (66.7%) were aged <12 months. The suspicious index case of a girl aged 34 months was not vaccinated with MCV1 and got measles after a trip to Philippines, and molecular genotype was revealed as B3. Measles outbreaks in the community such as a restaurant were followed by this one imported case. According to analysis of 18 patients admitted in isolation ward, the median level of C-reactive protein (CRP) was 0.38mg/dL and that of lactate dehydrogenase (LDH) was 1200IU/L. All of the 18 patients had LDH levels above the normal range. Age correlated with CRP (ρ=0.528, P=0.024) and LDH (ρ=0.501, P=0.034). The duration of fever was correlated with the duration of fever before rash (ρ=0.898, P<0.01). The duration of hospitalization was correlated with CRP (ρ=0.586, P=0.011). The white blood cell counts were correlated with the levels of LDH (ρ=0.505, P=0.033), aspartate aminotransferase (ρ=0.507, P=0.032), and alanine aminotransferase (ρ=0.481, P=0.043). Early weaning of maternally derived measles antibodies therefore vaccination of MCV1 at a young age from 9 months to 12 months should be considered in situations of early exposure. Furthermore, there is a call for consideration of scheduling an earlier age for the first dose of MMR vaccine in Europe. It is necessary for Korea to investigate the duration of the presence and quantitative analysis of maternal measles antibodies in infants and to reconsider the timing of MCV1.

Dynamic maternal measles antibody level in infants: a longitudinal study

To understand the dynamic maternal measles antibody level in infants in Guangzhou. Women who delivered babies in a maternal and child health care hospital in Guangzhou and their infants who were never affected by measles were included in our study. All the serum samples collected from mothers and infants were tested by using enzyme linked immunosorbent assay(ELISA)for the quantitative measurement of measles IgG antibodies. A longitudinal sero-epidemiological study was conducted to investigate the duration of the presence of measles maternal antibodies in infants based on the measurement at different time points(0, 3, 5, 7 month). A total of 689 mothers and their 691 infants(two pairs of twins)were included in the study. The concentration and the sero-positivity rate of measles antibody in mothers was 513.8 mIU/ml and 81.6% respectively. The concentration and the sero-positivity rate of measles antibody in infants was 732.8 mIU/ml and 87.3%, respectively. The measles antibody levels of newborns were positively associated with those of mothers(r=0.917 5, P<0.001), which declined rapidly at 3 months after birth and mostly turned to be negative at 7 months after birth. Measles antibody turned be negative at 3 months after birth in low, middle level groups, but remained to be positive in high level group at 5 months after birth. The maternal measles antibody could rarely protect infants at age of 8 months even though mother had been vaccinated or acquired natural immunity. It is suggested to adjust the time of the first dose measles vaccination in infants and increase the measles antibody level of child bearing aged women to reduce the incidence of measles in infants.

Waning maternal measles antibodies in infants

Waning maternal measles antibodies in infants

Periconceptional multiple-micronutrient supplementation and placental function in rural Gambian women: a double-blind, randomized, placebo-controlled trial

Background: Maternal micronutrient deficiencies are commonly associated with clinical indicators of placental dysfunction.Objective: We tested the hypothesis that periconceptional multiple-micronutrient supplementation (MMS) affects placental function.Design: We conducted a double-blind, randomized, placebo-controlled trial of MMS in 17- to 45-y-old Gambian women who were menstruating regularly and within the previous 3 mo. Eligible subjects were pre–randomly assigned to supplementation with the UNICEF/WHO/United Nations University multiple micronutrient preparation (UNIMMAP) or placebo on recruitment and until they reached their first antenatal check-up or for 1 y if they failed to conceive. Primary outcome measures were midgestational indexes of utero-placental vascular-endothelial function [ratio of plasminogen-activator inhibitor (PAI) 1 to PAI-2 and mean uterine-artery resistance index (UtARI)] and placental active transport capacity at delivery [fetal to maternal measles antibody (MMA) ratio].Results: We recruited 1156 women who yielded 415 pregnancies, of which 376 met all of the inclusion criteria. With adjustment for gestational age at sampling, there were no differences in PAI-1 to PAI-2 or MMA ratios between trial arms, but there was a 0.02-unit reduction in UtARI between 18 and 32 wk of gestation (95% CI: −0.03, −0.00; P = 0.040) in women taking UNIMMAP.Conclusions: Placental vascular function was modifiable by periconceptional micronutrient supplementation. However, the effect was small and supplementation did not further affect other variables of placental function. This trial was registered at www.controlled-trials.com as ISRCTN 13687662.

Association of Birth Weight with Gestational Age and Maternal Measles Antibodies

Introduction: Maternal measles antibody (MMA) offers protection against measles in early childhood, however, certain determinants of this antibody lives much to be desired. The aim of the study were to determine the association between birthweight (BW) and gestational age (GA), to assess the relationship between BW and MMA, to correlate GA with MMA and to examine the combined effects of BW and GA on MMA.Material and Methods: The work was a hospital-based cross-sectional descriptive study. Babies were enrolled using systematic random sampling method. The babies BW was measured using the bassinet scale; enzyme linked immunosorbent assay was used to determine MMA. GA of babies was determined using the mothers' last menstrual period (LMP) or by Dubowitz score or by Obstetric ultrasound scan. Data were analysed using SPSS statistical software version 16, Illinois, Chicago USA and a computer program for epidemiologist PEPI version 3.01. Spearman’s correlation (rho), Kendall’s rank correlation (tau b) and Jonckheere-Terpstra test of association of ordinal variables were determined. Univariate analysis was used to investigate the combine effects of BW and GA on MMA. Likely-hood ratio Chisquare (?2) was used for categorical data. Goodman-Kruskal index rank order of predictive association (tau) of ordinal data was also calculated.Results: 200 babies were enrolled, 101 (50.5%) were males and 99 (49.5%) females. 169 babies (84.5%) had normal BW, 117 (58.5%) were delivered at term. The mean BW was 3.04 (0.58) at 95% CI (2.96 – 3.12) kg. Association between BW and GA was significant (p=0.003), the predictive value for the association was also significant (p=0.039). Significant correlation was also observed between GA and MMA (p&lt;0.001).Conclusions: There was a significant association between BW and GA and MMA correlated well with GA.J Nepal Paediatr Soc 2015;35(1):6-12

Newborn measles antibody profile in a teaching hospital: Can sex of babies determine measles IgG acquisition from their respective mothers?

Known sex specific differences in fetal, neonatal morbidity and mortality have been documented. Sex differences also exist in birth-weight centile with males being larger than females at birth. However, these sex differences are not fully explored when studying passive measles immunity acquired by babies from their mothers. Moreover, the mechanisms that confer these sex differences are to a large extent unknown. Therefore, this study assessed sex of babies as a determinant of measles immunoglobulin G acquisition from their respective mothers. One hundred and seventy four newborn babies were enrolled in this study. Enzyme linked immunosorbent assay was used to measure maternal measles antibodies (MMA) from sera collected from these babies at birth. Gestational age of the newborn babies was determined using the Nagele rule, ultrasound scan reports and the Dubowitz criteria. Sex and mean MMA of these babies was compared using the Student's t test. Significant comparison existed between mean MMA and sex of post term babies (P = 0.000), such that post term males had higher levels of MMA than females. However, overall sex and mean MMA comparison of these babies was not significant (P = 0.977). There were more MMA in male post term babies relative to their female peers; however, overall sex comparison of MMA was not significant. Therefore, there is the need for further study.

Transplacental transfer of macromolecules: proving the efficiency of placental transfer of maternal measles antibodies in mother: infant pairs.

Background:Smaller substances <600 Daltons (Da) can transit human placenta while larger ones >1000 Da may not. This may not be consistent because maternal measles antibodies (MMA) are large immunoglobulin G molecules with molecular weight of 150,000 Da, could cross the placenta in mother-infant pairs.Aim:The objective was to assess the efficiency of placental transfer of MMA in mother-infant pairs at birth.Subjects and Methods:Sera collected from mother-infant pairs were analyzed for MMA using enzyme-linked immunosorbent assay. Gestational age (GA) of newborns was determined using the last menstrual period, ultrasound scan, and the Dubowitz criteria, whereas their birth weight (BW) was measured using the bassinet weighing scale.Results:Correlation coefficient (r) of MMA of mother-infant pairs at birth was significant (P < 0.01) and comparison of mean MMA for term and postterm deliveries were significant (P = 0.001) and (P = 0.007) respectively. Goodman and Kruskal's Gamma rank correlation of GA and BW was also significant (P< 0.001).Conclusion:Passage of MMA across placenta was efficient and newborn infants are protected from measles at birth.

Predicting changing measles epidemiology in an urban West African population

Background: Measles remains a major cause of childhood morbidity and mortality. Control of measles is complicated by pattern of measles transmission in which children are infected after they lose their protection from maternal measles antibodies (MMAs). As such, infants become measles prone before the age of measles immunization. This study, therefore, aimed at predicting changing epidemiology of measles in children in Maiduguri, Borno State, Nigeria. Materials and Methods: One hundred and thirty six infants at the age of seven months were enrolled in this study using the stratified random sampling method, and were tested for MMAs using enzyme-linked immunosorbent assay. Results: Sixty nine (50.7%) of the infants were males and 67 (49.3%) females, giving an approximate male to female ratio of 1.03:1. Comparing mean MMA levels of infants, for those who were protective and those who were unprotective was significant (P<0.0001). Most of the infants (125, 91.9%) had unprotective MMAs at seven months of age. Conclusion: Majority of infants in this study had unprotective MMAs at seven months of age and are more susceptible to measles. There is the need to monitor similar trend of events in other parts of Nigeria and abroad in order to report changing ecology of measles.