MEASLES VACCINATION .7. FOLLOW-UP STUDIES IN CHILDREN IMMUNIZED WITH 4 DOSES OF INACTIVATED VACCINE

Children immunized with 4 doses of formalin‐killed (FK) whole virus vaccine containing adjuvant and aqueous, purified hemagglutinin prepared from Tween‐ether (TE) treated material in different combinations have been followed serologically and clinically during a period of 3 to 4 years after the last dose of vaccine. The average decline in HI antibody titers was about 10‐fold during this period of time, except in children who had received 4 doses of TE vaccine. The latter group displayed about a 40‐fold decrease in titers. Four out of 10 children exposed to cases of regular measles displayed clinical symptoms of varying degrees of severity. Two more children responded with a rise in HI antibody titer only. All these reactions occurred in children with a pre‐exposure HI serum titer of 160 or higher. A case of pneumonia was encountered in connection with exposure to wild virus in a child who had received only 2 doses of FK vaccine. Copyright © 1969, Wiley Blackwell. All rights reserved