<unk> s act by binding to and neutralizing venoms. The principle of<unk>  is based on that of vaccines, developed by Edward Jenner; however, instead of inducing immunity in the person directly, it is induced in a host animal and the hyperimmunized serum is transfused into the person. The host animals may include horses, donkeys, goats, sheep, rabbits, chickens, llamas, and camels. In addition, opossums are being studied for<unk>  production.<unk> s for medical use are often preserved as freeze-dried ampoules, but some are available only in liquid form and must be kept refrigerated. They are not immediately inactivated by heat, however, so a minor gap in the cold chain is not disastrous. Some ophiophagic animals produce natural antidotes that render them immune to certain snake venoms. It does not appear that humans could be naturally immune to animal venom, but some individuals may be more or less susceptible to its effects. A person can build up immunity to a particular venom through frequent low and increasing doses (about every 21 days), but this immunity is only in effect while he or she is undergoing the dose regime. According to Greek history, King Mithridates did this in order to protect himself against attempts of poisoning, therefore this procedure is often called mithridatism. However, cytotoxic venom causes injury even at low doses meant to build resistance and the long-term effects of venom dosing in general have not been studied. Thus, there is no practical purpose or favorable cost/benefit ratio for this, except for people like zoo handlers, researchers, and circus artists who deal closely with venomous animals. Mithridatism has been tried with success in Australia and Brazil and total immunity has been achieved even to multiple bites of extremely venomous cobras and pit vipers. Because neurotoxic venoms must travel farther in the body to do harm and are produced in smaller quantities, it is easier to develop resistance to them than directly cytotoxic venoms (such as those of most vipers) that are injected in large quantity and damage immediately upon injection.
Antivenom
Altitoxin
Antitoxin
Snake antivenom
Anti-tetanus immunoglobulin
Rabies immunoglobulin
QuantiFERON
Sarin