What is a booster vaccination and what is its purpose?
A booster vaccination is an extra dose of a vaccine. If possible it should be administered before the protection provided by initial immunisation diminishes. Its purpose is to maintain or restore, and prolong, the protection provided by the vaccine. Other vaccinations besides the one for COVID-19 also lose their effect over time and should be renewed. For example, the FOPH recommends getting regular boosters for the vaccination against diphtheria and tetanus (lockjaw).