Published online by Cambridge University Press: 15 May 2009
Three groups of post-vaccination sera were studied for vaccinial antibody by precipitation, haemagglutinin-inhibition, complement-fixation and neutralization tests. All sera were negative by precipitation and many by haemagglutinin-inhibition and complement-fixation tests, but most showed neutralizing activity at serum dilutions of 1/10 or higher. The differences in antibody titres between the three groups of sera were most probably related to the past history of revaccination.
This investigation was supported in part by Public Health Service Grant AI–1632–16 VR from the National Institute of Allergy and Infectious Diseases, by the World Health Organization and by the Marcus T. Reynolds III Fund.