The impact of new vaccine introduction on the coverage of existing vaccines: A cross-national, multivariable analysis

► Policy-makers often wonder whether introductions of new vaccine have had positive or negative effects on overall immunization. ► New vaccine introductions for 176 countries between 2000 and 2008 were analyzed for any association with coverage of DTP3. ► New vaccine introductions were not associated with DTP3 coverage. ► DTP3 coverage was instead predicted by armed conflict, coverage of antenatal care, infant mortality, and health spending.