Abstract
Analysis of rubella epidemics and a measles epidemic in isolated Alaskan communities where these diseases had not occurred for many years indicated that rubella was at least as infectious as measles. Further, inapparent rubella with seroconversion was much more common among those who were alive during the previous epidemic; while among those who were born subsequent to the last epidemic, the rate of apparent illness was much higher. K was possible that these older individuals were partially immune as a result of the prior exposure and the recent episode was a 2nd rubella infection.