CIDRAP Report Calls for Novel Influenza Vaccine
By Matthew Watson, November 9, 2012
A recently released report by Michael Osterholm and colleagues at the University of Minnesota’s Center for Infectious Disease Research and Policy (CIDRAP) provides a detailed review of the status of influenza vaccine in the United States. It also calls into question the efficacy of currently available vaccines. Now licensed in the US are a trivalent influenza vaccine (TIV) and a live attenuated vaccine (LAIV). Both target the hemagglutinin (HA) surface protein and have to be reformulated annually to match circulating viral strains. Osterholm and team identify overconfidence in these products as a major barrier to technological advancement. In their view, an ideal vaccine would be universally protective against all influenza virus strains, but, at minimum, should confer immunity against H1, H2, H3, H5, and H9 viruses.1
Influenza Vaccine Efficacy and Effectiveness
The report authors acknowledge that because currently available vaccines are generally safe and do provide some level of protection, they should continue to be used until more effective vaccines are available. However, they cited the results of a previously published meta-analysis 2 where they found that the available efficacy and effectiveness data are either not available or vary among vaccines and age of target populations. The methodology of that review specifically excluded influenza vaccine studies that utilized a clinical diagnosis of influenza-like illness or serological surveys as an endpoint. Studies were included only if they used laboratory methods to verify the diagnosis of influenza (ie, RT-PCR or culture). Using these criteria, the authors were able to identify evidence of efficacy in healthy adults aged 18–65 years who received TIV (59% pooled estimate) and in children aged 6 months–7 years who received LAIV (83% pooled estimate). They were also able to estimate effectiveness (69% pooled estimate) for the monovalent vaccine developed against pandemic H1N1. In all other cases—including in those above age 65—the evidence was either inconclusive or absent.2
CIDRAP’s review also highlights current regulatory and research processes, which are geared toward incremental changes in influenza vaccines (eg, high dose, intradermal, quadrivalent) rather than supporting what the authors refer to as “game changing” vaccines. These products would provide long lasting and broad protection from infection, be highly effective in at-risk populations, have a low incidence of adverse events, and be inexpensive to manufacture, distribute, and administer. Additionally, the authors note that the current emphasis on augmenting production of vaccine may overshadow development of vaccines with improved efficacy.
The CIDRAP team asserts that there is an urgent need for novel, non-HA antigen vaccines that confer broad protection against influenza viruses, but their review of currently registered clinical trials turned up only 13 such vaccines in development out of 177 trials. The authors recommend that the federal government declare the development of such a product a national priority, undertake a highly coordinated leadership effort, and provide the necessary resources to support the needed research and development.
Osterholm MT, Kelley NS, Manske JM, et al. The Compelling Need for Game-Changing Influenza Vaccines: An Analysis of the Influenza Vaccine Enterprise and Recommendations for the Future. CIDRAP. October 15, 2012. Available at: http://www.cidrap.umn.edu/cidrap/files/80/ccivi%20report.pdf. Accessed 11/6/2012
Osterholm MT, Kelley NS, Sommer A, Belongia EA. Efficacy and effectiveness of influenza vaccines: a systematic review and meta-analysis. Lancet Infect Dis. 2012 Jan;12(1):36-44.