The development of a safe and effective vaccine against RSV would benefit greatly from data on the immune responses in healthy adults naturally exposed to the virus. RSV infection has been shown to increase and induce short-lived circulating antibody secreting cells and produce an increase in the RSV specific antibody titres but very limited data is available on the cellular immune responses induced by RSV during natural infection in healthy adults. The existence of cell mediated immune response against RSV in humans has been described but characterization of this response remains poor and simultaneous analysis of several immunological parameters have not been attempted in an RSV exposed population before.