Vaccination against the nematode Trichinella spiralis in high- and low-responder mice. Effects of different adjuvants upon protective immunity and immune responsiveness.

Groups of NIH and C57BL/10 (B10) mice were vaccinated subcutaneously with excretory/secretory material from the nematode parasite Trichinella spiralis using a variety of different adjuvants, i.e. complete Freund's adjuvant (CFA), 'TiterMax', alum and ISCOMs. ISCOMs were also given orally. NIH mice, known to be rapid responders to T. spiralis, expelled their worms earlier than usual with vaccination. The slow-responder B10 mice did not expel worms any earlier, no matter which adjuvant was used. The antibody isotype response profiles following vaccination with the four adjuvants did not differ significantly; however NIH mice generally produced higher levels of antibody than B10 and CFA induced the highest overall response. NIH cells yielded stimulation indices far in excess of the B10 following in vitro stimulation with T. spiralis antigen. Secretion of interleukin-5 (IL-5) and interferon-gamma (IFN-gamma) by these cells followed similar trends, i.e. higher levels from NIH than B10. A high IL-5 level in the NIH strain was accompanied by low-level IFN-gamma production following infection, whereas the IFN-gamma response was not observed in B10 supernatants. This study shows that vaccination using these adjuvants did not appear to modify the immune response qualitatively, but the magnitude of the response was affected greatly.