In this placebo controlled trial of rubella vaccines administered randomly to first-grade children in Memphis, 100% of 206 susceptible HPV-77 DK 12 recipients, 92% of 214 susceptible HPV-77 DE 5 recipients, and 87% of 213 susceptible HPV-80 recipients developed rubella hemagglutination-inhibition (HI) titers of ≥ 1:10 within seven weeks after vaccination (September 1968). The geometric mean titers (GMT) of respondents to HPV-77 DK 12, HPV-77 DE 5, and HPV-80 were 1:183, 1:108, and 1:124, respectively. There had been no significant decrease in GMT by the 39th week after vaccination (April 1969). Between September and April, a period in which rubella was occurring in Memphis, significantly fewer (P < 0.01) HPV-77 DK 12 vaccinees had rises in HI titer from < 1:10 to ≥ 1:10 or fourfold or greater from at least 1:10 than the other study groups. Vaccinees with titer rises had lower initial titers than vaccinees without rises.
Abrutyn E, Herrmann KL, Karchmer AW, Friedman JP, Page E, Witte JJ. Rubella Vaccine Comparative StudyNine-Month Follow Up and Serologic Response to Natural Challenge. Am J Dis Child. 1970;120(2):129–133. doi:10.1001/archpedi.1970.02100070073007