Measles vaccine field trials in Alaska. 3. Two-year follow-up of inactivated vaccine followed by live, attenuated vaccine and of immune globulin with live, attenuated vaccine.

Measles vaccine field trials in remote Alaskan Eskimo communities were followed up after two years. In one village, administration of inactivated measles virus vaccine had been followed in five to seven weeks by live, attenuated measles virus vaccine. In the second village, live vaccine had been given with measles immune globulin. Natural measles appeared in both villages after vaccination. Following exposure to natural measles, antibody rises were noted primarily among subjects with low titers. Titer rise was more frequent among those who received inactivated vaccine plus live vaccine. Two years after vaccination, and in spite of the booster effect of natural measles, titers among those who received inactivated vaccine plus live vaccine had fallen to low or undetectable levels in more than half of the recipients (51 of 85), suggesting that this combination may not produce lasting protection. Geometric mean titers were highest after natural measles, intermediate after live vaccine plus immune globulin, and lowest after inactivated vaccine plus live vaccine.