Preventive vaccines: these are the typical vaccines against infections, such as COVID or those applied in childhood. Their purpose is to protect against eventual infections which can be caused by the pathogens targeted by the vaccine. The enhanced immunity generated after vaccination persists for long periods of time in the absence of changes in the infectious agents. However, they sometimes change their structure (mutations) which requires successive vaccinations to ensure efficient protection. This is the case with the influenza (flu) vaccine.
Therapeutic vaccines: these types of vaccines are designed to treat patients whose disease responds to the effect of the vaccine. These vaccines induce an immune response that helps the patient’s disease (e.g. allergy immunotherapy). They are also used to prevent recurrences in susceptible patients, such as in the case of patients with recurrent urinary tract infections or in cancer patients to prevent tumor relapses.