Final answer:
HPV strains 16 and 18 are high-risk oncogenic types associated with the majority of cervical cancer cases and can be prevented through vaccines like Gardasil and Cervarix.
Step-by-step explanation:
HPV strains 16 and 18 are classified as high-risk oncogenic strains due to their strong association with cervical cancer. In fact, these two strains are linked to the majority of cervical cancer cases. High-risk strains of HPV, including HPV 16 and HPV 18, are known for their ability to disrupt normal cellular functions, which can lead to the development of precancerous changes in the cells of the cervix. This can progress to invasive cervical cancer. Both of these strains can be targeted through vaccination, with vaccines like Gardasil protecting against these and other high-risk HPV types. Gardasil 9 covers nine high-risk HPV types, while Cervarix is specific to HPV 16 and 18, which are the primary culprits in cervical cancer cases.