ID Biomedical Corporation has completed its final analysis of immune responses of adults in its phase II trial of StreptAvax vaccine, the Company's subunit protein-based vaccine against group A streptococcal diseases.

The results show that, among the 70 subjects who received StreptAvax, there was a statistically significant (p < 0.0001) increase in serum antibodies to every one of the 26 M protein serotypes, and to the Spa protein. The average increase in antibody levels across the population of StreptAvax recipients was 11.3 fold for each vaccine peptide. Viewed as individuals, StreptAvax recipients responded to a median of 25 (91%) of the different streptococcal peptides in the vaccine, and each peptide elicited a significant immune response in a median of 87 per cent of vaccinees. By way of contrast, the group of 20 subjects who received hepatitis A vaccine had no significant antibody increase against any of the streptococcal peptides.

StreptAvax is designed to induce protective immune responses to 26 different M protein serotypes of group A streptococci which are responsible for causing the vast majority of disease, including the types that are the most common causes of "strep throat" and invasive infections (so-called "flesh-eating disease") in North America as well as the types historically associated with the most feared complication of strep throat - acute rheumatic fever. In addition, the vaccine also includes a 27 th peptide derived from another protein, called Spa, which is expressed by many important pathogenic strains of streptococci.