Approaches to improved influenza vaccination

Inactivated influenza vaccine (Ivac) has had an important impact on reducin g attack rates of influenza and reducing the severity of illness amongst th e vaccinees who still acquire infection. Ivac is most efficacious amongst y oung, otherwise healthy subjects and least effective against elderly at hig h risk. This is in part because Ivac does not appear to significantly reduc e infection rates and in part because response rate and final antibody tite r are lower in the elderly. Therefore Ivac does not eliminate disease in th e elderly who are prone to complications when any virus replication occurs. Simultaneous administration of intra-nasal live attenuated influenza vacci ne (Livac) and Ivac reduces the infection rate and thus illness rate amongs t high-risk elderly. Presumably this is because of the ability of Livac to stimulate secretory antibody which neutralizes virus at the mucosal surface . Other approaches are examining the benefit of baculovirus recombinant vac cine or adjuvanted Ivac to determine if the higher serum antibody these vac cines produce compared to Ivac, will diffuse onto the mucosal surfaces and in a similar fashion, neutralize virus at that site. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.