What defines inactivated vaccines?

Inactivated vaccines are defined by their method of production, which involves killing the virus or bacteria that causes the disease they are designed to protect against. This process ensures that while the pathogen can no longer cause disease, it still retains enough of its structure to be recognized by the immune system. When administered, the immune system can recognize the inactivated components as foreign, leading to the production of an immune response, including the generation of antibodies.

The key characteristic of inactivated vaccines is that they do not require the pathogen to replicate. Instead, they rely on the body's ability to mount an immune response to the killed virus or bacteria. This is why statements regarding the necessity of replication or long-lasting immunity through replication are not applicable to inactivated vaccines. Additionally, the suggestion that inactivated vaccines are purely polysaccharide based is incorrect, as many are based on whole viruses or bacteria that have been inactivated rather than being based solely on polysaccharide components.