A trial on effective surveillance and impact of vaccination on screening for cervical cancer was conducted in Italy:
•To evaluate the effectiveness of vaccination in 25-year old women, not previously vaccinated, at the time of their first access to cervical cancer screening
•To evaluate the immune response following vaccination at this age
•To study the dynamics of the infection after vaccination, including the possible change in the frequency of non-vaccine HPV types
•To evaluate cytological abnormalities reductions in vaccinated women
•To understand the impact of vaccination on screening activity
All the 25-year old women invited to the Florence Cervical Cancer Screening program were asked to be enrolled in a vaccination study; at enrolment, women performed Pap test , HPV test , HPV serology test and received free offer of HPV vaccination (Cervarix®). The presence of high risk (HR) HPVs in cervical samples was evaluated by HC2 and HPV genotyping was Performed by INNO-LiPA Genotyping Extra t. HPV antibody testing was performed on an established and validated HPV serology method based on Luminex technology . HPV type specific seroreactivity was evaluated on all samples collected before and after vaccination (3-year post vaccination)
a strong reduction for any HR-HPV infection was observed in vaccinated women compared to unvaccinate (16% vs 21∙4%,p=0∙12), particularly for HPV16 (3∙2% vs 6∙7%,p=0∙08) and HPV31,33,45 (2∙1% vs 6∙5%,p=0∙02) For women HR-HPV negative at enrolment, results reveal no infections due to HPV16, HPV18 and HPV31,33,45. A strong antibody response was observed for HPV16 and18 but also for HPV16/18 related types .The compliance to the recall at a new screening round after 3 years was 82∙3% for vaccinated women in the present study and 77.5% in not vaccinated women , showing that vaccinated women maintained a high adherence to screening
In conclusion our results show a reduction for HR-HPV infections, cytological abnormalities and colposcopy referral rate in vaccinated women at 25yo and at this age the best strategy seems to vaccinate HR-HPV negative women. Considering the high efficacy of HPV vaccine also for adult women and taking into account that cervical cancer screening program are implementing HPV primary test starting from 30 years old, vaccinating HPV negative women could become part of the screening process. As we know, this topic is still a complex issue and different parties are involved: a cost effectiveness model would be useful to assess the best strategy to integrate screening and vaccination; our data could allow developing this model.