Vaccinasjon

Vaccinasjon, commonly known as vaccination, is a method of stimulating the body's immune system to protect against a specific disease. It typically involves introducing a weakened or inactive form of a pathogen, such as a virus or bacterium, or a component of it, into the body. This non-infectious agent, called a vaccine, prompts the immune system to recognize it as foreign and develop a defense against it.

When the vaccinated individual is later exposed to the actual disease-causing pathogen, their immune system is already prepared to fight it off. This often results in preventing the disease entirely or significantly reducing its severity. Vaccinasjon plays a crucial role in public health, contributing to the eradication or control of many infectious diseases that were once widespread and deadly.

The development of vaccines has been a cornerstone of modern medicine. They are administered through various routes, most commonly injection, but sometimes orally or nasally. The process of immunization, where a person becomes resistant to a disease, is the outcome of successful vaccinasjon. Herd immunity, a form of indirect protection, occurs when a large percentage of a population is vaccinated, making it difficult for a disease to spread and thereby protecting those who cannot be vaccinated, such as infants or individuals with compromised immune systems. While generally safe and effective, like any medical intervention, vaccines can have side effects, which are typically mild and temporary.