Adjuvanticity of stearyl tyrosine on inactivated poliovirus vaccine

Preliminary studies of some of the properties of stearyl tyrosine have shown that it is non-toxic, free of adverse reactions at the sites of injection, non-pyrogenic, stable upon storage and easy to sterilize. Formalin inactivated poliovirus vaccine (IPV) adjuvanted with stearyl tyrosine hydrochloride induced significantly higher titres of antibodies in non-human primates, after two injections, than the non-adjuvanted vaccine. Furthermore, the adjuvanted vaccine, even when diluted 1:4, showed consistently higher antibody titres as well as a longer persistence of antibodies than the non-adjuvanted undiluted vaccine. These studies suggest that stearyl tyrosine is an excellent and cost effective adjuvant for IPV. Hence further investigation with this novel synthetic compound would be worthwhile to ascertain its adjuvanticity for IPV in human subjects.