Rotavirus Antibodies in the Mother and Her Breast-Fed Infant

Abstract

The transfer of rotavirus antibodies from 25 healthy mothers to their breast-fed infants was investigated during lactation (mean, 3.9 mo.; range, 1-9 mo.). The destiny of these antibodies in the infants'' gastrointestinal tract and serum was examined. Rotavirus-specific Ig were analyzed by the ELISA (enzyme-linked immunosorbent assay) technique. All mothers had rotavirus IgA and IgA in seurm; .apprx. 80% of the mothers had low concentrations of rotavirus ScIg (antirotavirus immunoglobulin containing secretory component) in serum at the beginning of lactation declining to about 45% at the end of lactation. From a few days after delivery to .apprx. 2 wk later, the concentrations of rotavirus IgA and ScIg in milk declined. Thereafter, they remained unchanged. There was a positive correlation among the concentrations of rotavirus IgA in serum and rotavirus IgA and ScIg in milk. Rotavirus IgG in the infants'' serum correlated with that of the mothers. Few samples of the infants'' duodenal fluid contained rotavirus IgA or ScIg; .apprx. 80% of the infants'' fecal samples contained rotavirus ScIg and IgA. Rotavirus IgA and ScIg disappeared from the infants'' feces after cessation of lactation. Infants receive rotavirus IgG through the placenta and rotavirus ScIg and IgA in constant amounts via milk throughout lactation. The small intestine is flushed with rotavirus ScIg and IgA at each breast-meal; these antibodies survive proteolysis in the gut. A possible protectional effect of rotavirus ScIg or IgA requires frequent breast-meals. The effect is limited to lactation.