Efficacy of measles vaccination for women before pregnancy by the change of measles neutralizing antibodies in their children up to 9 months old in Ba Vi district, Hanoi City

Abstract

Recent measles outbreaks have shown the increasing of measles incidence among children under 9 months, not yet at the age for the first dose of measles vaccination. An intervention study conducted on 1,235 women aged 18 to 30 in 25 communes and towns in Ba Vi district, Hanoi city by vaccination against measles for 952 women and influenza vaccine for 283 women to evaluated efficacy of measles vaccination for women before pregnancy by the change of measles neutralizing antibodies in their children up to 9 months old in Ba Vi district, Hanoi city. The efficacy index was the concentration of measles virus neutralizing antibody in serum reaching the level of protection against measles in children at the time of birth, 3, 6, 9 months of age. The results showed that there was no difference in the percentage of children having measles virus neutralizing antibodies at 3, 6, 9 months of age between the intervention group and the control group. In both groups, the rate of 3 month-old children having antibodies at the sufficient level to prevent measles decreased quickly, about 4 times to 17%, and continued to wane at 6 and 9 month-old children to 7.2% and 2.9%, respectively. In general, there was insufficient evidence on the effectiveness of pre-pregnancy measles vaccination in preventing measles in children under 9 months of age.