A study was designed to better characterize the serological responses of infants in the second year of life to live, attenuated, B level, Jeryl Lynn mumps-virus vaccine given singly since previous studies with small numbers had implied poorer seroconversion ratios in this age group. Of the 88 infants 12 to 24 months of age, 17 (or 19%) were shown to have had prior infection with the mumps virus. Seroconversion rates in the 71 infants who were initially seronegative were comparable to those reported in other children and adults. The study clearly confirms the feasibility of administering the mumps-virus vaccine either singly or in combination to infants greater than or equal to 12 months of age.
Wilkins J, Williams FF, Wehrle PF. Infants' Responses to Live, Attenuated, B Level, Jeryl Lynn Mumps Vaccine. Am J Dis Child. 1972;124(1):66-67. doi:10.1001/archpedi.1972.02110130068010