ScienceDaily: Cervical cancer vaccine holds up:

A vaccine protecting against two types of viruses that cause cervical cancer has demonstrated unusual staying power, new research shows.

In a follow-up study to a randomized clinical trial, researchers found antibody levels in the study subjects remained steadfast for up to four and a half years. Researchers say the results confirm the success and safety of the vaccine Cervarix, which is designed to guard against two cancer-causing human papillomaviruses, HPV 16 and 18.