Measles Vaccination-Reply

Abstract

In Reply.— Dr Needles suggests that a recent mutation in the measles virus might account for the occurrence of measles due to secondary vaccine failure. We are aware of no laboratory data to support this view. If a clinically significant antigenic shift had occurred in recent years, we would expect a high incidence of measles in adults rather than the low rate currently observed. Furthermore, secondary measles vaccine failure has been reported since the early 1970s. 1 The data provided by Drs Polkowski and Hayner demonstrate that measles can occur even in persons who have received more than one measles vaccination prior to the onset of an outbreak. We observed the same phenomenon in three patients during the outbreak in Dane County. However, the Dearborn data lack sufficient statistical power to justify the conclusion that revaccination is of no benefit in persons initially vaccinated before 12 months of age.