Genetic differentiation of a measles virus isolated from a case occurring 15 days after measles vaccination.

Measles virus (MV) is an important human pathogen・ Since 1 954, when Enders and Peebles succeeded in isolating MV; many live measles vaccines have been developed, and are widely used today (1)・ Liv? measles.Vaccines are highly immunogenetic and effective ln PreVentlng a natural infection ofwild-type MV As some recipients develop vaccine-induced side-reactions such as fever and rash (2-4), it is becoming important to differentiate vaccine-derived viruses from wildtype viruses. We report here the results of genetic differentiation of an MV isolated from a case occurrlng 15 days after live measles vaccination.