From an immunological viewpoint, why would it be inadvisable for a mother who has recently given birth to move with her newborn to a foreign country where there are endemic diseases not prevalent in her homeland?

Question

What will be an ideal response?

Answer 1

Newborn infants are afforded passive immunity to the pathogens in their environment through IgG and dimeric IgA. IgG is transferred transplacentally, and dimeric IgA is acquired through breast milk. If an endemic infection develops in the newborn infant, the IgG antibodies in the infant's bloodstream may not have the appropriate specificity for the foreign antigens because the mother would not have encountered these antigens previously in their homeland, and therefore the newborn infant would not have acquired them passively during fetal development. Furthermore, without maternal IgG, infants are particularly susceptible to infection for the first 6 months of their life, when their immune systems are unable to produce significant levels of IgG. In addition, infections that breach mucosal surfaces may be more likely to develop during this time because dimeric IgA against such a pathogen will not be formed in the breast milk until about a week after the mother has been exposed to the same pathogen.