Answer: Booster dose of vaccine is given to elicit a secondary immune response ( by means of re-exposure of pathogen in the booster dose) so that more number of long lived antibody producing plasma cells are produced in the body.
Due to this, a higher level of protection is created in the body.
Whenever the body encounters the disease causing agent, it can easily clear off the infection.
Thus, booster dose serves as an additional vaccine dose to boost the memory of the immune system against a particular disease.
Example of vaccine that require booster dose- HPV ( human pappiloma virus), Hepatits A, Hepatitis B, Polio.
