Genotype Distribution Change After Human Papillomavirus Vaccination in Two Autonomous Communities in Spain

Context It has been more than 10 years since the human papillomavirus (HPV) vaccination program was initiated in most advanced countries. Thus, it seems necessary to change the uterine cervical cancer screening strategy. Molecular-based tests are considered essential in this scenario. Objective We aimed to review the distribution of the HPV genotypes after the introduction of the vaccination program with Cervarix (R) and Gardasil 4 (R) in two autonomous communities in Spain, looking for possible changes in distribution and the occurrence of a herd effect. Design A cross-sectional study was performed in 45,362 samples that were processed in the Cantabria and Aragon communities during the period from 2002 to 2016. We compared the genotype distribution before and after the vaccination program was initiated. Results Genotypes HPV6 and HPV11 have decreased significantly after the introduction of the vaccine. HPV16 has had a decrease, but not a significant one in the statistical analysis. However, HPV31, HPV52, and HPV45 have increased in percentage. A replacement phenomenon with other genotypes not included in the vaccine has been observed in our population. Conclusions Continued surveillance is needed to provide further indication of any changes over time in the genotypes in circulation. This will be facilitated by monitoring the genotyping results from the new model of cervical screening using primary HPV DNA testing.

Automated summary

This study reviewed the distribution of HPV genotypes in two autonomous communities in Spain after the introduction of HPV vaccination programs, finding a significant decrease in some genotypes but also observing replacement phenomenon with genotypes not included in the vaccines. Continued surveillance is needed to monitor any changes in genotype distribution over time.