Vaccination is artificially acquired immunity – it involves putting a killed, weakened or partial pathogen into the body. Although the vaccine does not make the recipient ill, the vaccine stimulates production of antibodies that provide immunity.
Vaccination is like faxing the nation – putting a copy of a germ into everyone to prevent them catching a disease.
Example of a virus vaccine
Flu vaccines often contain antigens taken from three different strains of flu. The three strains are determined each year by the World Health Organisation, based on the latest available information on which strains are most prevalent.
Example of a bacteria vaccine
Live oral typhoid vaccine is often in the form of delayed-release capsules and protects against typhoid fever in people aged 6 years and older who are at increased risk because they are travelling to areas where typhoid is more common.