Intranasal Inactivated Influenza Vaccines: a Reasonable Approach to Improve the Efficacy of Influenza Vaccine?

Intranasal Inactivated Influenza Vaccines: a Reasonable Approach to Improve the Efficacy of Influenza Vaccine? Jpn J Infect Dis. 2016;69(3):165-79 Authors: Tamura S, Ainai A, Suzuki T, Kurata T, Hasegawa H Abstract Influenza is a contagious, acute respiratory disease caused by the influenza virus. The mucosal lining in the host respiratory tract is not only the site of virus infection, but also the site of defense; it is at this site that the host immune response targets the virus and protects against reinfection. One of the most effective methods to prevent influenza is to induce specific antibody (Ab) responses in the respiratory tract by vaccination. Two types of influenza vaccines, intranasal live attenuated influenza virus (LAIV) vaccines and parenteral (injectable) inactivated vaccines, are currently used worldwide. These vaccines are approved by the European Medicines Agency (EMA) and the US Food and Drug Administration. Live attenuated vaccines induce both secretory IgA (S-IgA) and serum IgG antibodies (Abs), whereas parenteral vaccines induce only serum IgG Abs. However, intranasal administration of inactivated vaccines together with an appropriate adjuvant induces both S-IgA and IgG Abs. Several preclinical studies on adjuvant-combined, nasal-inactivated vaccines revealed that nasal S-IgA Abs, a major immune component in the upper respiratory tract, reacted with homologous virus hemagglutinin (HA) and were highly cross-reac...
Source: Japanese Journal of Infectious Diseases - Category: Infectious Diseases Authors: Tags: Jpn J Infect Dis Source Type: research