Influenza vaccination coverage among US-Mexico land border crossers: 2009 H1N1 pandemic and 2011-2012 influenza season

Background: The high volume of US-Mexico land border crossings can facilitate international dissemination of influenza viruses. Methods: We surveyed adult pedestrians crossing into the United States at two international land ports of entry to assess vaccination coverage during the 2009H1N1 influenza pandemic and 2011-2012 influenza season. Results: Of 559 participants in 2010, 23.4% reported receipt of the 2009H1N1 vaccine. Of 1423 participants in 2012, 33.7% received the 2011-2012 influenza vaccine. Both years, those crossing the border >= 8 times per month had lower vaccination coverage than those crossing less frequently. US-border residents had lower H1N1 coverage than those in other locations. Vaccination coverage was higher for persons age >= 65 years and, in 2010 only, those with less than high school education. Although most participants believed it is important to get vaccinated, only half believed the influenza vaccine was safe and effective. The main reasons for not receiving the influenza vaccine were beliefs of low risk of disease, time constraints, and concerns about vaccine safety (in 2010) or efficacy (in 2012). Conclusions: International land border crossers are a large and unique category of travelers that require targeted binational strategies for influenza vaccination and education.