Effect of Hydrochloric Acid Concentration on the Stabilization of Poliovirus at High Temperature

Abstract: Attenuated poliovirus Sabin strains type 1 LSc 2ab and type 3 Leon 12a1b have been stabilized in different concentration of hydrocholoric acid (HCl) between pH 1.3 to 3.0 at 50•Ž for 15 minutes. These strains were temperature stable at pH 2.0 which corresponds to the concentration of HCl in human stomach. The infection route of attenuated poliovirus strains administrated in the form of oral vaccine to children is similar to that of natural infection by wild strains of poliovirus. The mechanism of poliovirus distribution in human has already been explained by Sabin (1956) and Bodian & Horstmann (1965). Both these theories mentioned that neurovirulent as well as attenuated strain reaches to gut through stomach. The pH of human stomach is 1.3 to 1.6, because the concentration of hydrochloric acid is about 0. 18%. Wallis and Melnick (1962) reported that maximum stabilization of attenuated poliovirus strain was observed at pH 4.0 against heating for 15 minutes at 50°C. In this study, we demonstrated the stabilization of attenuated poliovirus strain by hydrochloric acid, at pH 2.0 at high temperature. Attenuated poliovirus Sabin strains type 1 LSc 2ab and type 3 Leon 123 ^ wer