Multiple vaccine and pyridostigmine interactions: effects on cognition, muscle function and health outcomes in marmosets.

Following active service during the 1990/1991 Gulf Conflict, a number of UK and US veterans presented with a diverse range of symptoms, collectively known as Gulf Veterans Illnesses (GVI). The administration of vaccines and/or the pretreatment against possible nerve agent poisoning, pyridostigmine bromide (PB), given to armed forces personnel during the Gulf Conflict has been implicated as a possible factor in the aetiology of these illnesses. The possibility that long-term health effects may result from the administration of these vaccines (anthrax, pertussis, plague, yellow fever, polio, typhoid, tetanus, hepatitis B, meningococcal meningitis and cholera) and/or PB, have been investigated using a non-human primate model, the common marmoset. This paper reports the results from three aspects of the study, cognitive behaviour (performance of a touchscreen mediated discrimination task), muscle function (performance of a simple strength test) and general health. There were no marked long-term changes in cognition, muscle function or health that could be attributed to vaccines and/or PB administration. Statistical differences related to treatments were only observed in two aspects of cognition and one of clinical chemistry. These changes were transient in nature and their magnitude were minor and, in consequence, was not regarded as having long-term biological significance.