An appreciation of the seminal contributions of John Brooksby and Fred Brown on foot and mouth disease.

John Brooksby was an outstanding Scottish veterinary virologist who worked at the Pirbright Institute (Pirbright) for 40 years, including 16 as the institute's director. He devised quantitative methods for measuring neutralising antibodies and perfected a complement fixation test for the diagnosis, typing and strain differentiation of foot and mouth disease (FMD), especially when combined with neutralisation. He identified four of the seven types of FMD virus (FMDV) and many subtypes. Consequently, the institute was designated the World Reference Laboratory for FMD. As director, Brooksby also oversaw advances in the pathogenesis, epidemiology and aerobiology of FMD and other diseases. His advice on the prevention and control of FMD was widely sought by international organisations and individual countries. Fred Brown was an eminent English biochemist and molecular virologist. He joined the Biochemistry Department at Pirbright in 1955, became head of the department in 1964, and in 1980 became deputy director of the institute. Advances under his leadership included the use of aziridines as inactivating agents for vaccine production, purification of FMDV suitable for biochemical analyses, demonstration of the infectivity of isolated RNA, analysis of the genomic and antigenic structure of FMDV, solving of the atomic structure of FMDV and demonstration of the potential for synthetic peptide vaccines to protect animals against virus challenge.