Effects of a nationwide Hib vaccine shortage on vaccination coverage in the United States

► A shortage of Haemophilus influenzae type b (Hib) vaccine occurred in the United States during December 2007 to September 2009. ► Data from the 2009 National Immunization Survey (NIS) were analyzed to examine effects on Hib vaccination coverage. ► As expected booster dose coverage was reduced, but primary series coverage was also reduced in some states.