Rokotusta

Rokotusta, or vaccination, is the medical practice of administering a vaccine to stimulate the body's immune system to develop protection against infectious diseases without causing the disease itself. Vaccines may contain inactivated or attenuated organisms, purified proteins, inactivated toxins (toxoids), or genetic material such as mRNA, and are designed to present antigens that educate immune memory.

By exposing the immune system to these antigens, vaccines trigger adaptive immune responses and the development of memory B and T cells. This can provide protection to the vaccinated person and, when a high proportion of the population is protected, contribute to herd immunity that reduces transmission.

Vaccination programs typically involve scheduled doses given at specific ages or intervals, sometimes with booster shots. Vaccines can be delivered by intramuscular, subcutaneous, oral, or nasal routes, and may be combined to reduce the number of injections.

Most vaccine side effects are mild, such as soreness at the injection site or fatigue; serious adverse events are rare. Vaccines undergo testing before approval and ongoing monitoring after licensure through pharmacovigilance systems, with guidance on eligibility and contraindications provided by health authorities.

Vaccination has dramatically reduced or eliminated many infectious diseases worldwide, preventing illness, hospitalizations, and deaths. Public health guidance emphasizes vaccination as a core preventive measure, while education and equitable access remain important considerations for maintaining high uptake.