Western Equine Encephalitis (WEE) is a viral disease primarily affecting horses and humans. It is caused by the Western Equine Encephalitis virus, which is transmitted through the bites of infected mosquitoes. Symptoms in humans can include fever, headache, and in severe cases, neurological issues. WEE is most common in the western United States and Canada, particularly during the summer months when mosquito populations are high. While the disease is rare in humans, it can lead to serious complications, especially in young children and older adults. Vaccines are available for horses to help prevent the disease.