Vaccines against epidemic and pandemic influenza

BACKGROUND: Preventative vaccination is the most effective way to control epidemic and, perhaps, pandemic influenza viral infections. However, the immunogenicity and efficacy of influenza vaccines against epidemic strains are suboptimal among older adults. The risk of serious complications from influenza viral infection is compounded by co-morbid conditions among older adults. Furthermore, despite annual influenza vaccination campaigns, the vaccination rates in high risk populations range from 60.5 - 79.2% only [1] . In addition, H5N1 avian influenza viruses have the potential to cause a pandemic. However, H5N1 vaccines currently licensed in the US are poorly immunogenic in high doses in the absence of an adjuvant even in healthy adults. OBJECTIVES: In this review, we address the current status of vaccines against epidemic and avian influenza viruses of pandemic potential. METHODS: We have limited the review to the discussion of technologies and strategies that have progressed to human clinical trials and/or licensure for seasonal and pandemic influenza. RESULTS/CONCLUSION: Improving the immunogenicity of vaccines against avian influenza viruses, as well as aggressive programs to vaccinate high risk populations against seasonal and pandemic influenza, are crucial for our public health efforts in minimizing the impact of influenza epidemics or pandemics.