The Effectiveness of Influenza Vaccination in Different Groups

ABSTRACT

Annual administration of the seasonal influenza vaccine, especially to persons known to be at elevated risk for developing serious complications, is the focus of current efforts to reduce the impact of influenza. The main factors influencing estimated inactivated influenza vaccine efficacy and effectiveness, the results obtained in different population groups, current vaccination strategies and the possible advantages of new vaccines are discussed. The available evidence suggests that influenza vaccines are less effective in the elderly than in young adults, but vaccination is encouraged by public health institutions due to higher mortality and complications. There is no consensus on universal vaccination of children yet economic studies suggest that yearly paediatric vaccination is cost saving. The benefits of herd immunity generated by paediatric vaccination require further study. Newer vaccines should be more and more-broadly protective, stable, easy to manufacture and administer and highly immunogenic across all population groups.

KEYWORDS:

• Influenza vaccines
• efficacy
• effectiveness
• study design
• vaccination policies
• risk groups

Financial & competing interests disclosure

This study was partially funded by the National Plan of I+D+I 2008-2011 and ISCIII-Subdirección General de Evaluación y Fomento de la Investigación (Project PI12/02079) and cofounded by FEDER, and the Catalan Agency for the Management of Grants for University Research (AGAUR Grant number 2014/ SGR 1403). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.