New antivirals for emerging viruses
Respiratory viruses are well known for their ability to mutate and, during the past few years, many have emerged including SARS and flu H5N1. Unfortunately, these viruses induce severe respiratory diseases in high risk patients, particularly the elderly. Through research on the elderly immune system, the EU-funded 'Immune response to respiratory virus infections and vaccination in elderly' (Respviruses) project aimed to develop appropriate antiviral strategies. Project researchers studied both the innate and acquired sections of the immune system and the response by both to the main emerging respiratory viruses such as human metapneumovirus (HMPV), respiratory syncytial virus (RSV) and flu H5N1. Most adults have antibodies against RSV so it was surprising that a clinical study revealed that infection with the virus was caused by lack of neutralising antibodies. For this purpose, an online database application developed by Respviruses can handle more than 2,000 datasets on infections and immune status against respiratory viruses. The Respviruses team also used an ageing animal model to test the efficacy of RNA interference-based therapies where short stretches of designer RNA can silence the viral genes and render the virus inactive. Six so-called Dicer substrate siRNA (DsiRNA) molecules were found to be very effective against HMPV in a novel high-throughput assay. Another breakthrough for the project scientists is that they have cultured the human bocavirus for the first time. Also an emerging disease, bocavirus causes lower respiratory tract disease. A detailed knowledge of the immune system response in the elderly to emerging respiratory diseases will aid the development of antiviral strategies. Furthermore, mortality and morbidity in the elderly will be reduced.