ANTIBODY PREVALENCE AND IMMUNOGLOBULIN IGG SUBCLASS PATTERN TO NORWALK VIRUS IN SWEDEN

The antibody prevalence in Sweden to Norwalk virus (NV) was investigat ed using a baculovirus expressed capsid antigen. One hundred thirty-tw o serum samples were examined for IgA, total IgG and IgG subclass anti bodies to Norwalk virus. In young children, NV IgG antibody prevalence was higher than the IgA prevalence, whereas no difference was found i n individuals older than 21 years. The IgG antibody prevalence was 50% in children below 5 years of age and increased to >80% in individuals older than 10 years of age. To examine the IgG antibody response in m ore detail, IgG subclass patterns were characterized. IgG 1 predominat ed in all age groups. IgG 4, usually detected after repeated exposure to antigen, was the second most prevalent subclass, but was only found in individuals older than 21 years of age. IgG 3 subclass antibodies were found in 13% and IgG 2 in 3% of the sera examined. IgG 3 subclass antibodies have been recognized as a marker for recent or ongoing vir al infections. (C) 1995 Wiley-Liss, Inc.