Anti-Rotavirus G Type-Specific and Isotype-Specific Antibodies in Children with Natural Rotavirus Infections

Abstract

Serum VP7 (G) type- and isotype-specific anti-rotavirus antibodies wereassessedamong children monitored longitudinallyover one or two rotavirus seasons in day care centers. Seventy-five pairs of blood specimens from 63 children were tested for anti-rotavirus antibodies. Stool specimens were collected weekly and tested for rotavirus antigen. G typing of detected rotaviruses showedthat sevenoutbreaks of Gland one ofG3 occurred during the two seasons.G type-specific responses to the outbreak strain occurred among 79%of infected children and 9%of children with infection not detected (P < .001), Of children infected with Gl, 54% had a heterotypic response; they wereolder (P = .048) and had higher preexistingG1 antibody levelsthan children who had only homotypic responses(P = .012). Higher IgA, IgG, and homotypic antibody levels to the antigenic site C of the Gland G3 VP7s correlated with protection against infection and illness, homotypic antibody independently of IgA or IgG titers.