Final answer:
About 70% of cervical cancer cases are attributable to HPV types 16 and 18, which are high-risk strains preventable by vaccines like Gardasil and Cervarix.
Step-by-step explanation:
The percentage of cervical cancer attributable to HPV types 16 and 18 is 70%. These two strains are classified as high-risk HPV types and they significantly increase the risk of developing cervical cancer. Regular Pap testing and vaccinations, such as Gardasil and Cervarix, can help detect and prevent infections from these high-risk HPV types. Vaccination is recommended before the onset of sexual activity to maximize effectiveness.