Influenza viruses are a major threat to health in livestock and humans. Influenza viruses are spread through contact, large respiratory droplets and aerosols, however factors affecting these modes of transmission are poorly understood. Swine Influenza (SI) viruses are implicated in human influenza, as sources of new influenza strains that are transmitted to humans by occupational exposure. Existing inactivated vaccines against SI are strain specific and do not protect against new strains. Therefore development of a broadly protective universal influenza vaccine that could provide long lasting immunity and prevent transmission is a high priority.
- To determine the importance of local and systemic immunity in protection against swine influenza
- To develop a 'universal' cross-protective swine influenza virus vaccine
- To determine the mechanisms of cross-protective immunity and identify correlates of protection
- To determine what factors contribute to transmission of swine influenza virus
- Local and Systemic Immunity. Improving SI vaccines will depend on understanding better the mechanisms and importance of systemic and local respiratory immunity in protection. The use of aerosol devices generating different particle sizes will enable us to determine whether it is essential to induce immunity in both the upper and lower respiratory tract. We are analysing which immune mechanisms are critical for protective immunity.
- Universal Influenza Vaccine. We are testing a candidate universal influenza virus vaccine, S-Flu, developed by Alain Townsend at the University of Oxford (Powell T et al, J Virol 2012). S-Flu has shown protective efficacy in mice and ferrets against homologous and heterologous challenge. We are studying the protective efficacy, optimal immunisation regime, and mechanisms and correlates of protection in pigs.
We are also studying recombinant cytomegaloviruses which generate powerful, long lasting immune responses with unusual specificity, properties that make them potentially attractive vaccine vectors. In collaboration with Dr Zsolt Ruszics, Freiburg, Germany, we are investigating their use as Influenza vaccines in livestock.
- Influenza Virus Transmission. Using natural models of host adapted influenza virus infection in pigs we are analysing the virological, clinicopathological and immunological parameters associated with transmission, as members of an sLoLa funded consortium. We will test the efficacy of different vaccine strategies not only to reduce disease severity but block transmission.
The same influenza viruses infect humans and pigs, and the disease has similar clinical signs and pathology, therefore pigs are an excellent model to study pathogenesis, transmission and immunity to influenza infection. Therefore insights gained from pig studies can be immediately applied to humans.
- Development of a universal vaccine which protects against all influenza virus strains would be an enormous advantage to prevent SI in pigs and reduce the zoonotic threat.
- Determining the viral and host factors related to transmission will enable better control measures to prevent disease, to be developed and applied.
- The methods developed for aerosol or mucosal delivery to pigs will have wide application to many respiratory pathogens of pigs, other large animals and humans.