Influenza vaccine-live

Influenza viruses cause recurrent and widespread seasonal epidemics in humans. Vaccination is the most effective means of preventing influenza infection. An alternative approach to inactivated influenza virus vaccines are live attenuated virus administered by nasal spray. Several approaches to developing live attenuated vaccines for influenza are under development. This chapter will focus on the cold-adapted LAIV that is licensed for prevention of seasonal influenza in the United States and several other countries. LAIV has significant advantages in convenience of administration. Safety, immunogenicity, efficacy and effectiveness data and the clinical experience with LAIV since licensure are discussed. In some studies in recent influenza seasons, low effectiveness of quadrivalent LAIV was reported against H1N1pdm09. With an updated strain, vaccine performance in terms of shedding and effectiveness have improved. LAIV has the potential to significantly contribute to the control of influenza and influenza-associated illnesses.