Rotavirus specific Salivary and Fecal IgA in Indian Children and Adults.

OBJECTIVE To compare serum, salivary and fecal IgA responses in infants and adults following rotavirus vaccination. STUDY DESIGN Laboratory testing of samples from clinical trials. SETTING Medical College Hospital. PARTICIPANTS 13 healthy adult volunteers not given vaccine, 20 healthy adult volunteers given one dose of bovine rotavirus tetravalent vaccine (Shantha Biotechnics), and 88 infants given 3 or 5 doses of Rotarix. OUTCOME MEASURES Serum, salivary and fecal IgA at one or more time points. METHODS IgA antibodies were estimated in serum, saliva and fecal samples by enzyme-linked immunosorbent assay, and normalized to total IgA in saliva. RESULTS In naturally infected adult volunteers, comparing serum and salivary IgA showed significant positive correlation (r=0.759; P=0.003). Of 20 vaccinated adults, complete samples showing change were available for 10; among them there was a significant positive correlation (P<0.05) between pre-vaccination serum and pre-vaccination salivary IgA but not between post-vaccination serum and post-vaccination salivary IgA. Of 88 infants given 3 or 5 doses of vaccine, 13 had more than 4-fold IgA response in serum, saliva and fecal samples, 6 had a 2-4 fold increases in all specimens. There was weak correlation between seroconversion rates measured by serum and salivary antibody responses. Salivary and stool assays were able to detect seroconversion in a few children in whom there was no detectable response in serum. CONCLUSIONS Evaluation of multiple samples is useful for intensive experimental study designs and may help improve our understanding of the induction and dynamics of immune responses to rotavirus vaccination.