Jiayao Lei

Research problem and specific questionsHuman papillomavirus (HPV) vaccination has demonstrated remarkable effectiveness in lowering the risk of HPV infections and cervical diseases. While the vaccination has been extended to boys, evaluation on the sex-neutral vaccination program is needed to understand the impact in preventing HPV-related diseases in both women and men.  Besides, there might be reproductive benefits for vaccinated women due to lower risk of HPV infection and treatment for cervical lesions, but yet to be investigated.In this register-based evaluation of HPV vaccination program, we proposed three working packages aiming to answer the research questions of 1) what is the long-term impact of HPV vaccination on cervical cancer, and how does the effectiveness differ by doses, time since vaccination and vaccine types? 2) What is the effectiveness of sex-neutral HPV vaccination in reducing the risk of HPV-related diseases in both men and women? 3) Can HPV vaccination lower the risk of adverse pregnancy outcomes?Data and methodThe project will use nationwide Swedish registers accessed through the existing advancing cervical cancer eradication strategies (ACCES) database at Karolinska Institutet. The project will involve large-scale epidemiological studies using an observational study design to evaluate the long-term impact of HPV vaccines.Societal relevance and utilisationThe research is highly relevant to the Global Strategy to Accelerate the Elimination of Cervical Cancer launched by WHO and United Nations Millennium Development Goal 4 to reduce child mortality. The findings from the project will provide comprehensive evidence on the long-term effectiveness of HPV vaccination and its impact on maternal and fetal health, which will aid clinicians and policy makers in making informed decisions about cancer prevention and optimizing HPV vaccination programs. The project is expected to have immediate benefits for all genders and promote vaccination coverage at the global level.Plan for project realisationThe project will be conducted over a 3-year period and collaborated with a team of epidemiologists, experienced physicians, and biostatisticians at Karolinska Institutet and Sahlgrenska University Hospital in Sweden.

Infection of oncogenic types of human papillomavirus (HPV) can cause six types of cancers, occurring in cervix, vulva, vagina, penis, anus and oropharynx. To date, HPV vaccination has been shown to have remarkable effectiveness in preventing the vaccine-type HPV infections and cervical disease in women, but less is known for the effectiveness of sex-neutral HPV vaccination program. The purpose of the project is to assess the impact of HPV vaccination programs in preventing HPV-related diseases and the potential benefits for pregnancy outcomes in large-scale epidemiological studies, utilizing nationwide Swedish registers. We proposed four working packages aiming to 1) examine the long-term impact of HPV vaccination on cervical cancer 2) evaluate the effectiveness of sex-neutral HPV vaccination 3) investigate the potential benefits (indirect effectiveness) on pregnancy outcomes 4) predict the impact of HPV vaccination on HPV-attributable cancers. The research is of great clinical significance and highly relevant to the Global Strategy to Accelerate the Elimination of Cervical Cancer launched by WHO and United Nations Millennium Development Goal 4 to reduce child mortality. The project will be conducted over a 4-year period and involves collaboration with a multidisciplinary team of experts in epidemiology, infectious diseases, gynecology and obstetrics, health economics, and biostatistics, both within Sweden and beyond.