An outbreak of encephalitis in 1938 Massachusetts sent health officials scrambling to find a way to explain the epidemic. Upon the deaths of eight children, brain matter from an infected child was used to inoculate horses, resulting in the confirmation of a distinct disease that could infect both humans and horses; researchers called it “eastern equine encephalomyelitis,” or EEE. Throughout the 1940s and 1950s, veterinarians, biologists, and other experimental scientists worked to uncover the disease’s transmission network, which directly related to the victims’ environment. Pastured animals and humans living close to or visiting wild areas seemed to be at the greatest risk for infection. With the creation of an effective vaccine that could prevent the disease in horses and an emergent understanding of how to prevent human exposure, EEE increasingly became associated with wildlife, only dangerous if it escaped its natural habitat to invade human society.
Using veterinary textbooks, agricultural manuals, and other scholarly publications, this paper investigates how animal vaccines were used in mid-20th century America to form a protective barrier between humans and wildlife diseases. This immunological barrier, I argue, served as a cultural boundary between wild and domestic spaces. In a period of increasing environmental awareness and concentrated efforts to seek interaction with natural spaces, the “wild” was both a place worthy of protection and a lingering threat to human health. Vaccines enabled people to come into more frequent contact with these spaces, manipulating certain animal bodies while drawing margins around human spaces and “wild” ones.
