immunizacj

Immunization is the process by which an individual's immune system is stimulated to develop protection against one or more diseases. It can be achieved through vaccination, which trains the body to recognize and fight specific pathogens, or, less commonly, by receiving antibodies directly for short-term protection.

Active immunization uses vaccines that introduce a component or a safe form of a pathogen to elicit an immune response and establish immunological memory. Passive immunization provides immediate but typically temporary protection by supplying preformed antibodies. Vaccines may contain live attenuated organisms, inactivated or killed organisms, subunits, toxoids, conjugates, or genetic material such as RNA or DNA, and they are delivered by various routes, most commonly injections but also nasal or oral forms for specific vaccines.

Immunization schedules outline the timing of doses to achieve and maintain protection, often starting in early childhood and including booster doses. New vaccines continue to emerge, including platforms like mRNA and viral vectors, alongside traditional types such as inactivated or weakened vaccines. The effectiveness of immunization is enhanced by high coverage, contributing to herd immunity, which reduces transmission and can protect individuals who cannot be vaccinated.

Safety monitoring and pharmacovigilance assess adverse events following immunization. While vaccines may cause rare side effects, the overall benefits in preventing disease and saving lives are well established. Immunization is a central component of public health, contributing to declines in morbidity and mortality from many infectious diseases worldwide.