Reduction in the prevalence of vaccine type HPV infection in young women offers the opportunity to monitor early effects of vaccination program. In Colombia, HPV vaccination was introduced in 2012 by National Immunization Program as primary strategy for the prevention of cervical cancer. We evaluated the program’s impact on genotype-specific HPV infection prevalence and the distribution in a group of non-vaccinated vs vaccinated young women aged 18-25 years old from Colombian
Young women aged 18–25 years from Manizales were invited to participate to this study through different communications strategies established at local health centers and Technological and higher education institutes. Cervical samples were tested for type-specific HPV DNA using a Linear Array genotyping test. HPV prevalence infection among 807 women in the post-vaccine group (2016–2017) were compared with prevalence of 951 women non-vaccinated (2015).
The prevalence of vaccine HPV genotypes (16, and 18) was significantly lower in vaccinated sample than in the non-vaccinated sample: 4.8 % (39/807) vs 15.5% (147/951); P < .001). Moreover, this reduction was higher in women vaccinated before starting sexual activity compared to after 2.4% (8/329) vs 6.5% (31/478) or women who received 3 doses (0%) or at least 2 doses (2.4%) of vaccine compared who received 1 doses 8.5% (28/329). We found evidence of cross-protection for HPV31, HPV 45 after vaccine introduction but it was no significant. Besides, we found slight increases in 4 nonvaccine high-risk HPV types (HPV39, HPV 51, HPV52 and 59). Interestingly, to HPV6/11 infection although the frequency was low in non-vaccinated group (3.3%), after vaccination it was 0.2% to HPV6 and no infection were observed to HPV 11.Finally, although there is a reduction of HPV vaccine type, the prevalence of other HR-HPV remain high, even a slight increase in the vaccinated population is observed (36.6% non-vaccinated Vs 39.7% vaccinated).
Five years after the introduction of the Colombian HPV vaccination program, a decrease in vaccine-targeted genotypes is evident. Variables such as age, number of doses and application of the vaccine before sexual debut increase the effectiveness of the vaccine. In addition, knowing the actual state of the HPV infection in Colombia allows to evaluate the current vaccination schemes and raises the possibility of inclusion of the nonvalent vaccine in our population.