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Time of perinatal immunization, thimerosal exposure and neurodevelopment at 6 months in breastfed infants

Rejane C Marques1, José G Dórea, Angelo G Manzatto

  • 1Fundação Universidade Federal de Rondônia, Porto Velho, RO, Brasil.

Acta Paediatrica (Oslo, Norway : 1992)
|May 1, 2007
PubMed

Insights

Early hepatitis-B vaccine (TCV) exposure in Brazilian newborns did not impact neurodevelopment at six months. Breastfeeding appears to protect infants from potential ethylmercury (EtHg) exposure challenges.

Area of Science:

  • Pediatrics
  • Immunology
  • Neuroscience

Background:

  • Hepatitis-B vaccine (TCV) administration timing varies for Brazilian newborns based on hospital type.
  • Infants born in public hospitals receive TCV within 24 hours, while those in private hospitals receive it 2-4 days later.
  • This study investigates the neurodevelopmental (ND) impact of this early TCV exposure difference.

Purpose of the Study:

  • To compare neurodevelopment in infants receiving TCV at different postnatal ages.
  • To assess the association between TCV ethylmercury (EtHg) dose and neurodevelopmental outcomes.
  • To evaluate the protective role of breastfeeding against potential neurodevelopmental delays.

Main Methods:

  • Gesell Developmental Schedules used to assess 82 healthy, exclusively breastfed infants at 6 months.
  • Evaluated motor skills, language development, comprehension, and social skills.
  • Analyzed neurodevelopmental outcomes in relation to TCV immunization timing and ethylmercury exposure.

Main Results:

  • No significant neurodevelopmental delays were observed in infants immunized within 24 hours compared to those immunized 2-4 days later.
  • Early TCV exposure timing and ethylmercury (EtHg) dose showed no significant association with neurodevelopmental outcomes.
  • Gesell Developmental Score did not correlate with ethylmercury levels in parenteral nutrition or hair mercury increase.

Conclusions:

  • Early exposure to thimerosal-containing vaccine (TCV) ethylmercury (EtHg) does not predict clinical neurodevelopmental delays at 6 months in breastfed infants.
  • Breastfeeding is a significant protective strategy for the central nervous system against early exposure challenges.
  • Further research may elucidate the long-term effects and protective mechanisms of breastfeeding.
Abstract

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