Basic information on vaccines

Vaccines are used to create immunity against infectious diseases. Many of these diseases have already been eradicated from Finland, and vaccines have also reduced their incidence worldwide.
  • The higher the vaccination rate of the population is, the lower the chance of the disease in question infecting those who are unvaccinated. Vaccines cannot be administered to certain groups, such as children with cancer. Vaccinating children is particularly important, as infectious diseases and their sequelae are the most dangerous to them.
  • When a person is vaccinated, the body receives a small quantity of the disease-causing microbe or part thereof in a form that engages the body’s natural defense mechanism against the pathogen. The vaccine makes the person immune to the disease without having to suffer the possibly life-threatening symptoms of the full-blown disease. Vaccines also spare the person from the sequelae of the disease.
  • The infectious diseases that vaccines protect people from are dangerous in themselves. Contracting these diseases can also cause permanent health problems, such as infertility.
  • Vaccines come in many different types. The active component may be inactivated, i.e. killed, pathogens, attenuated live microbes or detoxified parts of microbes.
  • Vaccines also contain tiny amounts of adjuvants and preservatives. They ensure the vaccine’s effectiveness, shelf life and composition. The most important additive is water, which is used to dilute the vaccine.
  • Vaccines usually confer long-lasting, and even lifelong, immunity. For certain vaccines, a single dose is enough to provide immunity for years or even decades. For others, several doses or subsequent booster shots are needed. Some vaccines are injected, while others are taken orally or as a nasal spray.
  • If a person gets infected with a disease in spite of being vaccinated for it, the disease is usually much less severe than for an unvaccinated patient, and the incidence of dangerous sequelae is lower.
  • Vaccines and their effectiveness and safety are constantly studied and monitored. A detailed register of potential side effects is maintained.

Further reading

Page published 30.4.2018
Page edited 30.7.2018