bólusetningu

Bólusetning, often translated as vaccination or immunization, is the medical practice of stimulating the immune system to protect against infectious diseases. It involves administering a vaccine that presents antigens or instructions to produce them, in a manner that does not cause disease in a healthy person.

Vaccines train the immune system by prompting an adaptive response, resulting in antibodies and memory B and T cells. When later exposed to the pathogen, the immune system can respond rapidly, reducing disease risk or severity. Vaccines come in several types: live-attenuated, inactivated, subunit, toxoid, conjugate, viral vector, and newer platforms such as mRNA or DNA vaccines. They are delivered by various routes, most commonly intramuscular injections, but some are oral or intranasal.

Safety and regulation: vaccines undergo phased testing for safety and efficacy before approval. Common side effects are usually mild (soreness at the injection site, fever). Serious adverse events are rare and monitored through surveillance systems. Ongoing post-licensing safety monitoring ensures continued evaluation and quality control across manufacturing and distribution.

Public health impact: widespread vaccination reduces disease incidence, complications, and deaths, and can achieve herd immunity, protecting those who cannot be vaccinated. The required coverage depends on the pathogen’s contagiousness and vaccine effectiveness. Vaccination programs have led to the eradication or substantial control of several diseases.

Development, ethics, and access: vaccine development proceeds from discovery to clinical trials, regulatory approval, and manufacturing. Ethics include informed consent and equitable access. Public health policies may include school-entry requirements or workplace vaccination in certain contexts; programs aim to reduce disparities and protect populations at risk.