the injection of an immune serum for the purpose of preventing infectious diseases in humans and animals; a relatively short-term passive immunity is produced, lasting one to four weeks. In modern medical practice, gamma globulin is increasingly being used in seroprophylaxis. Seroprophylaxis is indicated in many instances. For example, in epidemic areas immune serums are administered to persons who have been exposed to measles and whooping cough. They are also administered in order to prevent tetanus, in cases of animal bites in order to prevent rabies, and in cases of tick bites in order to prevent Russian spring-summer encephalitis. Repeated seroprophylaxis is administered in the preventative treatment of infectious hepatitis.

In veterinary medicine, seroprophylaxis is used in such cases as colibacillosis in calves and paratyphoid in young swine. Certain cases of infection, for example, pseudorabies, require the use of the globulin fractions of serum, whereas other infections, for example, foot-and-mouth disease, are prevented with milk serum from immunized animals.