1. Present address: GlaxoSmithKline, Stevenage, UK
2. MRC – University of Glasgow Centre for Virus Research, Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1QH, UK
3. Present address: Special Infectious Agents Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
4. Present address: Bristol-Myers Squibb, Mexico City, USA
5. Institute of Cancer and Genomic Sciences, Institute of Biomedical Research West, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK