The process of making an individual immune or resistant to an infectious disease, typically through the administration of a vaccine.
A biological preparation that enhances immunity to a particular disease. It contains an agent that resembles a disease-causing microorganism and is often made from weakened or killed forms of the microbe, its toxins, or one of its surface proteins.
The indirect protection from infectious diseases that occurs when a large percentage of a population becomes immune to an infection, thereby providing a measure of protection for individuals who are not immune.
A substance capable of inducing an immune response in the body, particularly the production of antibodies.
A protein produced by the immune system in response to the presence of a specific antigen. Antibodies help to neutralize or eliminate pathogens such as bacteria and viruses.
Any unexpected or unwanted reaction to a vaccine or medication, ranging from mild side effects like soreness at the injection site to severe allergic reactions.
An additional dose of a vaccine given after an initial series of doses to enhance and/or prolong the immune response.
The proportion of a population that needs to be immune to a particular infectious disease in order to prevent its sustained transmission within the population.
A specific situation or condition in which a vaccine should not be administered due to the risk of harm outweighing the potential benefits.
The ability of a vaccine to prevent the development of a specific disease under ideal and controlled conditions, typically expressed as a percentage reduction in disease incidence among vaccinated individuals compared to unvaccinated individuals.