Prevention of cervical cancer related to hpv infections

Melika Ziaoddini,1,* Ahmad ziaoddini,2 Sara zamani,3 Hassan ziaoddini,4

1. Pharmaceutical sciences branch, Azad University, Tehran, Iran
2. University of Medical Sciences, Tehran, Iran
3. Department of Microbiology and Microbial Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran
4. Health Psychology Department, Research Centre of Education Ministry Studies, Tehran, Iran

Abstract

Introduction

Human papillomavirus (hpv) infection is an important sexually transmitted infection worldwide. hpvs are divided into high-risk and low-risk genotypes. high-risk types are responsible for cancers like cervical cancer. cervical cancer is one of the most common cancers in women in the world. this cancer is developed through pre-malignant lesions known as cervical intraepithelial neoplasia from grades i to iii. about 663 new cervical cancers are diagnosed in each year in iran. despite of the introduction of pap smear test from many years ago, cervical cancer still has a high mortality worldwide. until now, three hpv vaccine types are produced in the world. hpv vaccine types and their characteristics are shown in table 1. table 1. names and characteristics of hpv vaccines which are used for prevention of cervical cancer. name characteristics approved by food and drug administration vaccine efficacy gardasil quadrivalent hpv4, prevention of infections caused by hpv types 6,11,16,18 2006 95% cervarix bivalent hpv2, prevention of infections caused by hpv types 16,18 2009 95% gardasil 9 ninevalent hpv9, prevention of infections caused by hpv types 6,11,16,18,31,45,52,58 2014 98% the aim of this review study is to review topic of hpv vaccines (immunogenicity, safety, efficacy and cost), which are useful for prevention of cervical cancer worldwide and also in our country.

Methods

We reviewed the papers without time limitation about cervical cancer prevention. our research contained papers with the relevant keywords: cervical cancer, hpv vaccine, gardasil, cervarix and gardasil 9. the data bases of science direct, medline scopus and google scholar were searched. the title and abstract of the papers were reviewed. some of the papers that investigated cervical cancer prevention were used in this study.

Results

Most topics of some papers about hpv vaccine worldwide: two studies in 2009, declared that cervarix and gardasil both are safe and effective for women’s health. in 2011 gee et al, performed a post-licensure safety assessment of gardail. in their study, no statistically significant increased risk for any of the pre-specified adverse events after vaccination was detected. stokley et al declared that hpv vaccines can be safety co-administered with other routinely recommended vaccines. in 2015, cuzick showed that gardasil 9 improved protection against cervical cancer precursor lesions and high-grade cervical disease. petrosky et al investigated efficacy of gardasil 9 comparing with gardasil. they illustrated that, hpv 6, 11, 16 and 18 seroconversions for gardasil 9 are higher than gardasil. most topics of some papers about hpv vaccine in iran: rasekh et al in 2014 said that, despite a quadrivalent hpv vaccine was added to the iran drug list, but it has not been added to the national immunization program until now. they investigated cost-effective of hpv vaccine in iran and they suggested gardasil is not cost-effective in iran based on the base-case parameter value. hamkar et al in 2017 showed that vaccination could have a great impact on the prevention of cervical cancer in iran. yousefi et al in 2017, updated parameters on cost- effectiveness of hpv vaccine. they showed hpv vaccination can be cost-effective in iran due to the new method by the world health organization.

Conclusion

Hpv vaccines are part of national immunization program in some countries. the vaccination program before the first sexual contact is more effective in the prevention of cervical cancer. despite gardasil is available in iran, it is not in the national immunization program. the reasons may be due to low incidence of cervical cancer in iran, lack of awareness and high cost of hpv vaccination. cervical screening is emphasized for all women above21 years of age with sexual activity in iran. cervical cancer screenings like hpv testing and pap smear tests are common in our country. we recommend that cervical screening should be free of charge with a full insurance coverage for iranian women.

Keywords

Cervical cancer, vaccine, gardasil, cervarix