IN 1966, Parkman, Meyer, and their colleagues described preliminary vaccine trials with a strain of rubella virus which had been attenuated by 77 passages in primary African green monkey kidney (AGMK) tissue culture.1,2 This strain, designated HPV-77, exhibited desirable qualities of immunogenicity and obvious attenuation in man. The present report describes our experience with HPV-77 virus in a series of vaccine trials which involved 48 children.
Materials and Methods
Vaccine.—The details of the preparation and safety testing of HPV-77 vaccine have been described by Meyer et al.1,2 The vaccine was supplied in single-dose vials which were stored at −65 C until use. Each vaccinated child received rubella vaccine (HPV-77), 0.5 ml subcutaneously. This dose represented 500 tissue culture interfering doses50 (TCID50), based on a titration in primary AGMK tissue culture using echovirus type 11 challenge.3Study Population and Experimental Design.—The 48 children were admitted