A polyvalent vaccine is a type of vaccine that is capable of protecting against multiple strains of a virus or bacteria. It is also referred to as a multivalent or combination vaccine. Often, these vaccines contain a mixture of antigens, which stimulate the immune system to build antibodies against each of the targeted strains. There are several synonyms for polyvalent vaccine, such as combined vaccine, cocktail vaccine, mixed vaccine, and multiplex vaccine. These vaccines have the advantage of providing broader protection against various strains, reducing the number of vaccinations required, and simplifying the vaccination process. Overall, polyvalent vaccines play a crucial role in preventing and controlling infectious diseases.