[Age of measles vaccination in Lombardy from the results of a seroepidemiological survey in Milan].

In view of the introduction of measles vaccination in Lombardy and since the age of vaccination is of paramount importance, measles h.i.a. were titrated in sera from 209 children between 0 and 6 years of age (of whom 171/0--2) and from 40 woman in the child-bearing age. As it could be expected from the high prevalence of adults with antibody (95%), 90% of umbelical cord sera have h.ia.,, Over 50% of children 15 days-3 months of age are still positive and afterwards the positivity decreases progressivley till a minimum of 8% in children 10--12 months old. Beginning with the second year of life the percentage of immune children grows slowly to reach 50% in the age group 3--6 years. The distribution of antibody titers between 6 and 12 months, time at which maternal antibody are largely waned, suggested that the infection with measles virus is a rare event in the first year of life, while a substantial number of children gets the infection between 18 and 24 months. From these results it appears that also in Lombardy measles vaccination should be given not before 13 months and not after 18 months of age.