Influenza / Flu Vaccination Doctor Near Me Influenza is an acute respiratory illness caused by influenza A or B viruses. It occurs in epidemics nearly every year. Influenza viruses change their antigenic characteristics frequently, and their spread depends upon the susceptibility of the population to viruses with newer antigens. Annual influenza vaccination is an important public health measure for preventing influenza infection. New influenza vaccines are produced each year. Vaccine antigens are selected based on global surveillance of influenza viruses circulating at the end of the previous season. The quadrivalent influenza vaccines contain two influenza A and two influenza B antigens. The types of quadrivalent vaccine include several inactivated influenza vaccines, recombinant and live attenuated vaccine. The US advisory committee on immunization practices recommends annual influenza vaccination for all individuals six or more months of age. In general, in the northern hemisphere, vaccination should be offered during September or October ( during March or April in the southern hemisphere ). If vaccination is not completed by October, it may continue to be offered throughout the influenza season, so as long as influenza viruses continue circulating. The influenza vaccines are well tolerated. The most common adverse effect is soreness at the injection site. Low grade fever, body ache, headache and fatigue are less common. The vaccination should always been done under the guidance and supervision of a specialist. Vaccination is associated with a reduced incidence of influenza. Among vaccinated individuals with breakthrough influenza infection, vaccination is associated with reduced mortality and disease severity.