Q: It is being stated that the cervical cancer vaccine (Gardasil) is the first vaccine ever designed to prevent a cancer. What are the side effects of this vaccine and is it really necessary?

A:Gardasil vaccine is based on two principles: (a) that cancer of cervix is due to HPV viruses (this is only partly true because even without such infection cancer can attack the patients) and (b) the vaccine is directed to create antibodies to four strains of HPV viruses. Hence if the cancer is likely to originate due to these specific four strains of HPV (and not other strains or reasons), then the individual will be protected. Generally the vaccine is useful in sexually active females with different male partners. However it is not very useful in other cases.