The main purpose of seasonal influenza vaccination is to avoid severe disease from infection with influenza virus. As of 2011, 39 countries and territories offer influenza vaccination to nationally-defined, high-risk groups in the Americas.
PAHO’s Technical Advisory Group on Vaccine-Preventable Diseases (TAG) recommends that the following groups of individuals may be targeted for vaccination in order to reduce the incidence of severe illness and premature death: older adults, children, those with underlying conditions, and healthcare workers. Because of the vulnerability of pregnant women to complications from influenza infection, TAG urges countries to increase vaccine uptake of pregnant women. Influenza vaccination in pregnancy is considered safe and is recommended for all pregnant women during the influenza season. This recommendation is motivated not only by the potential severe course of influenza during pregnancy, but also in order to protect infants against influenza during their vulnerable first six months of life.
Influenza vaccine is available in two preparations, Trivalent Inactivated Influenza Vaccine (TIV) and Live, Attenuated Influenza Vaccine (LAIV). TIV and LAIV are antigenically equivalent and contain three annually-recommended influenza strains--influenza A (H3N2), influenza A (H1N1), and influenza B. Each year, the influenza viruses in the vaccine are assessed on the basis of global surveillance for influenza viruses and may be changed. Most countries in the Americas Region are licensed for use of the TIV.