Knowra Vaccine Vaccine A biological preparation that trains the immune system to recognize a pathogen or disease target. Vaccination can prevent infection, reduce disease severity, or limit transmission.
Adaptive immune system : The immune system’s antigen-specific defenses, mediated chiefly by lymphocytes and immunological memory. Vaccines rely on adaptive responses to recognize their targets and respond more quickly later.
Immunization : The process of becoming protected against a disease through vaccination or, less safely, infection. Vaccination is one route to immunization, but the terms describe different things.
Routine vaccination : Scheduled vaccination given to populations to prevent diseases with established vaccines. Routine programs maintain broad protection against diseases that circulate or can return.
Live attenuated vaccine : A vaccine made with a weakened pathogen that can replicate but usually does not cause disease in healthy people. It can mimic infection and generate strong immunity, but may be unsuitable for some people.
Variolation : An early practice of deliberately exposing people to material from smallpox cases to induce protection. It preceded vaccination and demonstrated that induced exposure could prevent severe smallpox.
Antigen : A molecule or molecular feature recognized by antibodies or antigen receptors on immune cells. Vaccine antigens give immune cells a target to learn and remember.
Pathogen : An infectious agent, such as a virus, bacterium, fungus, or parasite, that can cause disease. Vaccines train defenses against a pathogen or a component it produces.
Herd immunity : Indirect protection that occurs when enough people are immune to limit an infectious agent’s spread. High vaccination coverage can reduce transmission and protect people who lack immunity.
Inactivated vaccine : A vaccine made from pathogens rendered unable to replicate, while retaining immune-stimulating components. It avoids replication, often trading some immune strength or duration for that constraint.
Edward Jenner : An English physician whose 1796 smallpox inoculation experiment helped establish vaccination. His work gave vaccination its name and launched a safer alternative to variolation.
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