MINNEAPOLIS (WCCO) — A national immunization survey states Minnesota’s child vaccination rates are declining.

Minnesota has dropped 13 spots in two years, from seventh in 2007 to 20th in 2009, for the primary vaccinations given to children 19 months to 35 months.

Children’s Hospitals and Clinics of Minnesota says this decline is part of a troublesome trend that could pose a threat to the overall health of Minnesota children.

The 2009 National Immunization Survey shows Minnesota’s childhood immunization rate fell to 77 percent in 2009 from 80 percent in 2007.

Based on the state’s current population of children, Children’s Hospitals and Clinics says each percentage point drop in the immunization rate exposes 4,230 kids to vaccine-preventable disease.