What type of vaccine can be made from pieces of a virus or bacteria?

Subunit vaccines are designed using specific pieces of a virus or bacteria, such as proteins or sugars, which are essential for eliciting an immune response. By isolating these components, subunit vaccines present the necessary antigens to the immune system without including the entire pathogen, thus avoiding the risk of causing disease. This type of vaccine can generate a strong immune response while being safer, especially for individuals with weakened immune systems.

In contrast, live attenuated vaccines contain weakened forms of the actual virus or bacteria, and inactivated vaccines use the entire pathogen that has been killed or destroyed; both options do not specifically focus on generating immunity from distinct pieces of the pathogen like subunit vaccines do. Toxoid vaccines, on the other hand, are made from inactivated toxins produced by bacteria, rather than from components of the bacteria or virus itself, differentiating them from subunit vaccines.