Clinical response to immunization with Cendehill strain rubella vaccine

Approximately 1,100 institutionalized Costa Rican children and young women were observed daily for 25 days following immunization with Cendehill strain rubella vaccine or placebo. Observations were made double blind by specially trained public health nurses supervised by a physician. Three subgroups were identified: preimmunization seropositive subjects receiving vaccine (S+); preimmunization seronegative subjects receiving vaccine (S-); and preimmunization seropositive and seronegative subjects receiving placebo (P). The 25 day observation time was divided into 5-day periods. For both sexes, two age groups, and each time period the number of days was recorded on which was present one or more of 13 signs and symptoms considered likely to reflect vaccine reaction. S-and P,S+ groups were compared statistically for each symptom or sign, time interval, and age sex subgroup. Most post-immunization signs and symptoms were not severe or disabling, of high prevalence, or usually more common in S- than P,S+ subjects. There were significantly higher frequencies of posterior auricular, posterior cervical, and occipital lymphadenopathy in S- than P,S+ children less than 15 years of age. Females had higher frequencies of headache and arthralgia than did the males studied, but frequencies in S- and P,S+ groups did not differ significantly.