Studies on vaccinia haemagglutinin: II. Some immunological properties

Abstract

1. Vaccinated rabbits develop serum anti-haemagglutinin after infection. The anti-haemagglutinin is not found to any appreciable titre in normal human and animal sera tested. It is present in the globulin fraction of rabbit serum and is stable at 70° C. for 30 min. but destroyed at 80° C. for 30 min.2. Observations over a period of 6 months of variations in serum antibodies in vaccinated rabbits demonstrate that whereas the agglutinin, precipitin and complement-fixing antibody varied in parallel with each other, the anti-haemagglutinin varied independently and in general remained more or less steady throughout the period.3. Some experimental observations of the haemagglutinin anti-haemagglutinin reaction are reported. The haemagglutinin inactivated by immune serum can be reactivated by boiling. Haemagglutinin adsorbed on to red cells can be eluted by subsequent addition of immune serum.4. Failure to obtain complement fixation with the haemagglutinin anti-haemagglutinin system is recorded.5. Vaccinia haemagglutinin is distinct from the L-S antigen.6. By absorption test, it has been shown that the anti-haemagglutinin is a distinct antibody related neither to L or S antibodies nor to neutralizing antibody.7. It is concluded that vaccinia haemagglutinin represents a new and distinct antigen occurring in a relatively large particulate state in vaccinia infected tissues. The possible theoretical implications of such findings are discussed.