Immune responses to measles and smallpox vaccinations in malnourished children

Abstract

Children with different levels of nutritional status were studied to determine their immune response to, and complications from, immunization with live measles vaccine and lyophilized smallpox vaccine. Two hundred forty-one children between the ages of 5 months and 9 years were examined to assess their nutritional status at the time of immunization. Sero-conversion was defined as a hemagglutination-inhibition titer to measles virus, of greater than or equal to 1:20 6 to 8 weeks after vaccination in initially sero-negative children. Of 111 initially sero-negative children 94% had an adequate immune response, shown by sero-conversion. Of 193 children without a smallpox vaccinationscar 97% were successfully immunized against smallpox. These rates of immune response were independent of age, sex, and nutritional status of the children. The geometric mean titer rise to measles immunization of groups, whose nutritional status was normal (greater than 90% of median weight for age), mildly (75 to 90%), moderately (60 to 75%), or severely (less than 60%) malnourished were 7.5, 8.8, 7.9, and 7.9, respectively. Malnutrition did not affect the children's ability to develop adequate immune response to measles of smallpox vaccine, and there were no major complications during the 8-week period of follow-up. Since measles is a very severe disease, which in malnourished children can carry a case fatality rate as high as 50%, malnutrition should be a prime indication for measles immunization, and certainly not a contraindication.