RESUMO
This cross-sectional study evaluated the immune status of non-vaccinated healthy infants to determine if it is possible to replace both measles vaccine [at 9 months] and measles, mumps and rubella [MMR] vaccine [at 18 months] with a single dose of MMR at 12 months. Serum samples from 566 children in Alexandria, Egypt showed a significant decrease in the seropositive rate to the 3 viral diseases with increasing age, but a significant increase in the seropositive rate among infants who were ranked 1st or 2nd in their family, full-term or born to mothers with no history of hypertension during pregnancy. We recommend administration of the first dose of MMR vaccine between 9 and 12 months of age, and a booster dose of MMR vaccine at 4 years of age