In Reply.—Dr Cunningham suggests that children who are vaccinated at or after 11 months of age are sufficiently protected against developing measles during a short-term outbreak. He incorrectly states that our vaccine efficacy rates were similar to those of Marks et al.1 In fact, we did not study vaccine efficacy because of the limitations of the method stated in the article.
As a former public health officer, I consider the relative risk of five or greater a clinically and epidemiologically significant unsafe level of measles protection. On a practical level, because of the data that were obtained from the outbreak in Livingston County, Michigan, in 1978, we required vaccination in all children who were vaccinated before 13 months of age. Since that outbreak, to my knowledge, there has not been a single reported case of measles in the county.
While our data do not show the effect of
FAUST HS. Measles Vaccine and Age at Immunization-Reply. Am J Dis Child. 1984;138(4):412. doi:10.1001/archpedi.1984.02140420078030