Effect of early measles vaccination (AIK-C strain) for preterm infants


Correspondence: Tetsuo Nakayama, MD, PhD, Laboratory of Viral Infection I, Kitasato Institute for Life Sciences, Shirokane 5-9-1, Minato-ku, Tokyo 108-8641, Japan. Email: tetsuo-n@lisci.kitasato-u.ac.jp



The level of maternal antibodies decreases more quickly in preterm than term infants, leaving them unprotected against measles. To protect premature infants from measles, an early vaccination trial was investigated.


Changes in the serum measles neutralization test (NT) antibody titer were examined in 152 infants (average gestational period, 29 weeks; average birthweight, 1203 g).


The average antibody titer (2n) was 23.5 at birth and 22.2 at 1–3 months of age, and in all cases, NT antibody titer decreased to <1:4 (150 IU/mL). The AIK-C measles vaccine was given to 17 preterm infants at the age of 6 months, and induced sufficient serological responses without any serious adverse events. NT antibody level did not decay during 12 months after vaccination.


Early immunization at 6 months of age is effective to protect preterm infants in the outbreak setting.