Marek's disease virus causes lethal tumours in chickens and turkeys. Pioneering research was done on the
disease by the IAH in the 1960s and 1970s, leading to the production of the first Marek's disease virus
(MDV) vaccine. This and subsequent vaccines have been immensely successful at keeping the disease in check.
However, periodically mutants of increased virulence occur and rise to prominence, requiring new vaccine
approaches to defeat them. It has long been suspected that the selection pressure driving the evolution of
ever-more virulent MDVs is vaccination itself; another example of a biological arms race. Recently, the IAH's
Professor Venugopal Nair and his collaborator Professor Andrew Read of Penn State University, USA, have
produced experimental evidence to support this hypothesis.
The picture shows presenter Dr Alice Roberts talking with Professors Read and Nair during filming at IAH for
a documentary in the BBC Horizon series, to be broadcast in 2011.