A simple and reproducible method for collecting nasal secretions in frail elderly adults, for measurement of virus-specific IgA.

The standard method for collection of respiratory secretions, by use of a nasal wash (NW) to measure virus-specific IgA, is problematic in frail elderly adults. Therefore, a simplified collection approach using a nasal swab (NS) is described. NW and NS samples were collected from healthy young and frail elderly adults, and IgA titers to respiratory syncytial virus (RSV) fusion and attachment glycoproteins were determined by enzyme immunoassay. Correlation between IgA titers in NW and NS was excellent for each of the antigens (correlation coefficients,.71-.93). In addition, NS results were reproducible when frail elderly subjects were sampled several weeks apart and were nearly equivalent to results from NW samples. The ability to sample nasal secretions by use of an NS when an NW is not technically feasible will facilitate the study of mucosal immunity to RSV as well as the study of mucosal response to candidate RSV vaccines in frail elderly populations.