Plum Island Animal Disease Center Like other RNA viruses, the<unk>  virus continually evolves and mutates, thus one of the difficulties in vaccinating against it is the huge variation between, and even within, serotypes. No cross-protection has been seen between serotypes (a vaccine for one serotype will not protect against any others) and in addition, two strains within a given serotype may have nucleotide sequences that differ by as much as 30% for a given gene. This means<unk>  vaccines must be highly specific to the strain involved. Vaccination only provides temporary immunity that lasts from<unk> s to years. Currently, the World Organisation for Animal Health recognizes countries to be in one of three disease states with regard to<unk> :<unk>  present with or without vaccination,<unk> -free with vaccination, and<unk> -free without vaccination. Countries designated<unk> -free without vaccination have the greatest access to export markets, so many developed nations, including Canada, the United States, and the UK, work hard to maintain their current status. Some countries such as Brazil and Argentina, which have large beef-exporting industries, practise vaccination in some areas, but have other vaccination-free zones. Reasons cited for restricting export from countries using<unk>  vaccines include, probably most importantly, routine blood tests relying on antibodies cannot distinguish between an infected and a vaccinated animal, which severely hampers screening of animals used in export products, risking a spread of<unk>  to importing countries. A widespread preventive vaccination would also conceal the existence of the virus in a country. From there, it could potentially spread to countries without vaccine programs. Lastly, an animal infected shortly after being vaccinated can harbor and spread<unk>  without showing symptoms itself, hindering containment and culling of sick animals as a remedy. Many early vaccines used dead samples of the<unk>  virus to inoculate animals, but those early vaccines sometimes caused real outbreaks. In the 1970s, scientists discovered that a vaccine could be made using only a single key protein from the virus. The task was to produce enough quantities of the protein to be used in the vaccination. On June 18, 1981, the US government announced the creation of a vaccine targeted against<unk> , the world's first genetically engineered vaccine. The North American<unk>  Vaccine Bank is housed at the United States Department of Agriculture's Foreign Animal Disease Diagnostic Laboratory at Plum Island Animal Disease Center. The center, located off the coast of Long Island, New York, is the only place in the United States where scientists can conduct research and diagnostic work on highly contagious animal diseases such as<unk> . Because of this limitation, US companies working on<unk>  usually use facilities in other countries where such diseases are endemic.
Foot-and-mouth disease
Tongue disease
Plague 
Chickenpox
Polymeal
Sealpox
Shingles
Mumps