Maternal Antibodies In Infants Research Articles

Enterovirus 71 Maternal Antibodies in Infants, Taiwan

Enterovirus 71 (EV71) causes life-threatening disease outbreaks in young children in Asia. This cohort study was conducted to understand the dynamics of maternal EV71 antibodies in Taiwanese young infants. Approximately 50% of neonates had detectable EV71 neutralizing antibodies, which declined to almost undetectable levels by 6 months of age.

Influence of maternal antibody against hepatitis B surface antigen on active immune response to hepatitis B vaccine in infants

Transplacentally acquired maternal antibodies in infants may inhibit active immune responses to vaccines. In this study, we compared the immunogenicity of the recombinant hepatitis B vaccine, which was intramuscularly injected at 0, 1, and 6 months of age, in 71 infants born to mothers with positive or negative antibody against hepatitis B surface antigen (anti-HBs). Forty-one infants born to anti-HBs positive mothers were all positive at birth. At 2 months after the second injection, anti-HBs in 30 infants with negative maternal antibody was significantly higher than that in 41 infants with positive maternal anti-HBs (191.1mIU/ml vs. 96.2mIU/ml, P=0.018). At one month after the full immunization, the anti-HBs levels had no statistical difference between maternal anti-HBs negative and positive groups, but the antibody response in infants with high maternal anti-HBs (>1000mIU/ml) was significantly inhibited. Nevertheless, all infants had anti-HBs higher than the protective level. In conclusion, passively acquired maternal anti-HBs in infants may to some extent impair the antibody response to hepatitis B vaccine. The long-term efficacy of hepatitis B vaccine in infants with high titers of maternal anti-HBs remains to be further evaluated.

Identification of HIV-1 infected infants and young children using real-time RT PCR and dried blood spots from Uganda and Cameroon

Serodiagnosis of HIV infection in infants born to HIV-infected mothers is problematic due to the prolonged presence of maternal antibodies in infants. Nucleic acid-based amplification assays have been used to overcome this problem. Here a simplified, one-tube, real-time, duplex reverse transcription PCR (RT PCR) assay is shown to detect HIV-1 total nucleic acid (TNA) isolated from dried blood spots. The detection of TNA, as opposed to DNA alone, increases the HIV target molecules and thus makes the assay more robust. This method was used to detect HIV from the DBS collected from HIV-1 exposed infants and young children in Uganda ( n = 128) and Cameroon ( n = 315). The gold-standards used were a plasma viral assay in Uganda and Amplicor DNA assay in Cameroon. The concordance of this real-time assay and the gold standards was 99.2% (127/128) and 99.4% (313/315) with the Ugandan and Cameroonian samples, respectively. This simple and cost-effective assay is potentially useful for the diagnosis of pediatric HIV infection and for evaluating programs to reduce mother-to-child transmission of HIV-1.

Safety and immunogenicity of respiratory syncytial virus purified fusion protein-2 vaccine in pregnant women

A randomized, double-blind, placebo controlled study was carried out to determine the safety and immunogenicity of RSV PFP-2 vaccine (Wyeth-Lederle Vaccines, NY) in 35 healthy women in the third trimester of pregnancy and their offspring. Infants were followed during their first RSV season for occurrence and severity of respiratory illnesses. RSV-PFP-2 vaccine was safe and well tolerated by pregnant women. Mild pain at the site of injection occurred in 65% of PFP-2 and 13% of placebo recipients ( P=0.005). There were no systemic reactions, fever, or serious adverse events associated with vaccine administration in mothers. All 35 infants were born healthy, and there were no differences among the groups in perinatal or neonatal outcomes, growth and development in the first year of life. During the RSV season, there was no increase in the frequency or morbidity associated with respiratory tract illnesses in infants of vaccine recipients. 15/20 (75%) vaccine recipients had a response to PFP-2 by Western blot vs. 0/15 placebo recipients ( P<0.01). 19/20 (95%) vaccine recipients had a ≥4 fold rise in IgG ELISA Ab after immunization with PFP-2 vs. 0/15 placebo recipients ( P<0.01). Geometric mean concentrations of IgG ELISA Ab were 4 fold higher in infants of vaccine recipients at birth, 2 and 6 months after delivery than in infants of placebo recipients ( P<0.01). A modest (0.5 log 2) increase in neutralization Ab was observed in vaccine recipients and their infants. The half-life of maternal antibodies in infants was ≥3 weeks. There was no evidence of enhanced T-cell or cytokine activity in infants of vaccine recipients vs. infants of placebo recipients. Vaccine specific anti-F IgA and IgG concentrations in breast milk were higher in mothers who received RSV-PFP-2.

Measles: a disease that has to be eradicated.

The incidence of measles is on the decline but it still claims the lives of one million children annually worldwide. The devastating effects of the disease on the health and nutrition of children in developing countries and its high mortality are well documented. The rapid decay of maternal antibodies in infants in developing countries results in early susceptibility to the disease and hence the general recommendation to vaccinate at the age of 9 months. Sustained international efforts have raised global vaccination coverage rates to around 80% at which level it has remained static. Many countries in the western hemisphere have eliminated the disease by adopting aggressive strategies, which include one-off 'catch-up' mass campaigns to vaccinate all children aged 1-14 years, 'mop-up' campaigns targeting children who were missed during the 'catch-up' campaign, efficient routine vaccination services capable of reaching 90% of infants, strong surveillance activities, prompt outbreak response, and 'follow-up' campaigns every 2-4 years which target 1-4-year-old children. This success story coupled with the fact that measles has many biological features favouring eradication, and considering that it is a severe and lethal disease still prevailing in many areas, calls for immediate international adoption of eradication goals within a specified period of time.