Vaktsiin

Vaktsiin is a medical intervention that prevents infectious diseases by training the immune system to recognize a pathogen without causing full illness. Most vaccines present antigens derived from the pathogen, such as inactivated organisms, proteins, or genetic material, sometimes delivered by harmless vectors. In response, the immune system produces antibodies and memory T and B cells that provide protection upon later exposure. In Estonian, vaktsiin refers to vaccines.

Vaccines come in several formats, including live attenuated, inactivated, subunit, toxoid, conjugate, and newer technologies such as messenger RNA (mRNA) and viral-vector vaccines. They are usually administered by injection, but some are given orally or nasally. Vaccination schedules vary by disease and country and often include primary series and booster doses.

Before a vaccine is approved for use, it undergoes preclinical testing and phased clinical trials to assess safety and effectiveness. Regulatory agencies authorize licenses and monitor safety after deployment, with ongoing surveillance for adverse events and rare complications.

Vaccines have dramatically reduced the burden of diseases such as smallpox, polio, measles, and diphtheria and are central to public health. High vaccination coverage can prevent outbreaks through herd immunity, protecting those who cannot be vaccinated.

The modern vaccine landscape includes rapid development approaches and platforms that can be adapted to new pathogens, as well as emphasis on cold-chain logistics to maintain potency.