In part 1 and part 2 of this series, we discussed the HPV vaccine and its links to ovarian insufficiency and autoimmune disease. In part 3, we turn to questions regarding the effectiveness of the vaccine to prevent cervical cancer, and the limitations of relevant clinical trials to detect such a type of effect.
Summary of Key Facts There are multiple obstacles in designing a valid clinical trial to prove the HPV vaccine could prevent cervical cancer, e.g. long lead time, lack of adequate informed consent, complexity between HPV infection and cervical cancer, and the negative impact of girls’ sexual behavior, which may worsen the risks of cervical cancer.
Most of the HPV’s interventional clinical trials have too short a follow-up time to draw a concrete conclusion.
In a large Swedish observational trial, which is treated as the most convincing study to prove the HPV vaccine’s effects on cervical cancer, a few confounding factors were not adequately balanced between the HPV vaccination group versus the unvaccinated group.
The National Cancer Institute’s Surveillance, Epidemiology, and End Results Program (SEER) data and another U.S. study found the HPV vaccine has no effects in reducing cancer rates.
Three other registry-based studies in Alabama, Australia, and the UK suggest that HPV vaccination is associated with increased cervical cancer rates in certain age groups. Long Lead Time from HPV Infection to Cervical Cancer
Typically, there is a long period from HPV infection to cervical epithelium abnormalities, then cervical cancer….