Vaccines for emerging viruses-a comprehensive update

Over the past decade several notable viruses have suddenly emerged from obscurity to become serious public health problems and global threats, provoking concern about sustained epidemic and pandemic transmission in immunologically naïve human populations. With each newly-emerged virus hazard comes the call for rapid vaccine development. Vaccines are an important component of disease prevention and control for emerging viral infections since in many cases other medical options are limited or non-existent and vaccines are also highly cost effective. Some infections for example may result in such a rapid clinical deterioration that the effectiveness of therapeutics is limited. Other new human virus infections maybe symptomless or cryptic and by the time a diagnosis is possible, a therapeutic maybe of limited use. While many classic approaches to vaccine development are amenable to emerging viruses, the application of molecular techniques in virology has profoundly influenced our understanding of virus biology and virus-host interactions, and so facilitated the development of new vaccine strategies and vaccine vector platforms. Vaccination approaches based on replicating, attenuated and non-replicating virus vector schemes have become useful vaccine tools. If our growing understanding of viral disease emergence and increasing range of vaccine strategies are coupled with an international commitment to underpin vaccine development, vaccine interventions for new and emerging viruses become a possibility.