Researchers analysing the design of HPV vaccines Cervarix and Gardasil efficacy trials found the Phase II and III trials had methodological problems that could have overstated the effectiveness of these vaccines against HPV.
We found insufficient data to clearly conclude that HPV vaccine prevents the higher-grade abnormal cell changes”
The researchers from Newcastle University and Queen Mary University of London, both UK, found that the trials were not designed to detect cervical cancer because it takes decades to develop; instead they detected low grade abnormal cell changes. These changes, according to the study collaborators, are not clinically important because “they often resolve spontaneously without progressing,” into cancers.
“We found insufficient data to clearly conclude that HPV vaccine prevents the higher-grade abnormal cell changes that can eventually develop into cervical cancer,” said Dr Claire Rees, Lead researcher from the Queen Mary University of London.