Nationwide measles epidemic in Ukraine: the effect of low vaccine effectiveness.

The WHO European Region has a measles elimination target for 2010. Between September 2005 and mid-June 2006, more than 50,000 measles cases were reported in Ukraine; many reportedly had received two doses of measles vaccine and over 60% were among persons 15-29 years old. To investigate vaccine effectiveness (VE), a case-control study was undertaken in Dnepropetrovsk region. VE for two doses of measles vaccine was 93.1%, providing insufficient population immunity for measles elimination. An additional dose of measles vaccine for these age-cohorts is required if Ukraine is to achieve measles elimination. Other republics of the former Soviet Union also need to consider a supplemental dose of measles vaccine for older age groups identified epidemiologically to be at increased risk for measles even though individuals may have already received two doses.