An<unk>  (or killed vaccine) is a vaccine consisting of virus particles, bacteria, or other pathogens that have been grown in culture and then killed to destroy disease-producing capacity. In contrast, live vaccines use pathogens that are still alive (but are almost always attenuated, that is, weakened). Pathogens for<unk> s are grown under controlled conditions and are killed as a means to reduce infectivity and thus prevent infection from the vaccine.<unk> s were first developed in the late 1800s and early 1900s for cholera, plague, and typhoid. Today,<unk> s exist for many pathogens, including influenza, polio (IPV), rabies, hepatitis A and pertussis. Because<unk>  pathogens tend to produce a weaker response by the immune system than live pathogens, immunologic adjuvants and multiple "booster" injections may be required in some vaccines to provide an effective immune response against the pathogen. Attenuated vaccines are often preferable for generally healthy people because a single dose is often safe and very effective. However, some people cannot take attenuated vaccines because the pathogen poses too much risk for them (for example, elderly people or people with immunodeficiency). For those patients, an<unk>  can provide protection.
Inactivated vaccine
Attenuated vaccine
Conjugate vaccine
Synthetic vaccine
Subunit vaccine
Genetically modified vaccine
Heterologous vaccine
Cell-based vaccine