Phacilitate, Barcelona Vaccine Forum 2010: Focus on correlates of protection against influenza

Abstract

The success of vaccination has been evidently shown, e.g. in the eradication of smallpox. However, vaccine development and registration has become increasingly challenging as definite parameters of efficacy are often lacking. One of the reasons is that, in contrast to treatment of overt disease through medication, prevention of disease by vaccines is difficult to measure. This is specifically evident with the introduction of a vaccine targeting a relatively uncommon infection such as induced by Meningococci C. The efficacy of this vaccine was finally determined only after large scale introduction in the UK as in the Netherlands since the number of clinical infections was too low to determine efficacy in clinical trials. Even for frequent pathogens such as influenza the protective effect of vaccination is sometimes questioned in the absence of clear parameters of protection. Here, ethical considerations prevent a double blind placebo-controlled trial that should enable an unambiguous insight. As a whole, the identification and usage of valid parameters of efficacy indicating protection is essential for vaccine development and registration. The introduction of these so-called correlates of protection (COP) is therefore essential. At the Phacilitate Barcelona Vaccine Forum 2010, identification of new COP for vaccines was a recurring focus of discussion, specifically for vaccines against influenza, and essential observations were made to advance its development.