New study charts paths to end cervical cancer

Cervical cancer is the fourth most common cancer for women in the world, with more than 660,000 new cases and nearly 350,000 deaths per year. Now, University of Maryland mathematicians have developed effective strategies to help contain and potentially eliminate the disease. The research, published last week in the journal Bulletin of Mathematical Biology, offers a new mathematical model that can help public health officials design effective vaccination and cancer screening policies.

“The study provides a clear way of showing how science is influencing policy,” said study senior author Abba Gumel, a Distinguished University Professor of Mathematics at UMD who holds joint appointments in the Institute for Health Computing and the Institute for Physical Science and Technology. 

Nearly all cervical cancer cases are caused by human papillomavirus (HPV), which is considered the most common sexually transmitted infection in the world. HPV, a vaccine-preventable disease, is often asymptomatic and resolves naturally within two years in 90% of cases, but persistent infection in the remainder can lead to cancer.

HPV vaccines, which are already offered and recommended in 147 countries, can minimize disease spread and cancer risk. The UMD researchers developed a new mathematical model to assess the efficacy of various vaccination strategies, which they tested with a case study on South Korea. 

“Cervical cancer is one of the few cancers effectively prevented by vaccines,” said study lead author Soyoung Park, a Ph.D. candidate in applied mathematics & statistics, and scientific computation at UMD. “It was important to check if the recent government program for offering vaccines is going to be enough to effectively control the disease in Korea.”

Building a case study for South Korea

The model presented in the study incorporates previously published demographic and epidemiological data to predict how HPV transmits across a population. It stratifies people by sex, vaccination status, HPV infection and cancer progression, and it was calibrated using South Korean cancer data from 1999 to 2020. The model can be used to test how different vaccination strategies fare over time.

Simulations of the model revealed that current South Korean policies are insufficient to eliminate HPV and related cancers in the country. South Korea’s National Immunization Program (NIP), which started in 2016, currently vaccinates roughly 80% of the nation’s girls aged 12-17. Another 30,000 women aged 18-26 receive “catch-up vaccinations” annually. Additionally, the National Cancer Screening Program provides regular Pap tests to detect cancerous lesions for roughly 61% of Korean women older than 20. These existing efforts will reduce HPV-associated cancer burden over time, the authors found, but they will not eliminate the virus. 

“It’s achieving the objective of reducing cases of cervical cancer, but it’s not going to eliminate it,” said Gumel, who has collaborated with the modeling team of Merck Inc., the company that originally developed the HPV vaccine. “The objective is elimination.” 

South Korea could eliminate HPV by expanding vaccine access, the researchers found. The authors explored two scenarios where NIP could be improved. The first involved expanding vaccine access to cover 99% of females. Additionally, because the authors found that immunizing boys has a strong spillover effect of protecting females, the second scenario involved maintaining the current 80% female vaccination coverage while vaccinating 65% of boys aged 12-17. Model simulations suggest that these efforts would eliminate HPV-related cancers in South Korea within 60 and 70 years, respectively. 

Both vaccination strategies for expanded coverage are feasible in Korea given that national coverage for infant immunizations, such as measles, under NIP approaches 98%, Park said. She added that public buy-in for vaccination campaigns is high in South Korea. 

“There’s very low vaccine hesitancy,” she said. 

“Vaccinating boys reduces the pressure of having to vaccinate a large proportion of females,” added Gumel, who also holds the Michael and Eugenia Brin Endowed E-Nnovate Chair in Mathematics. “It makes elimination more realistically achievable.”

Applying the model around the world

The two solutions the researchers propose would achieve herd immunity, meaning that people who cannot be vaccinated—for example, the elderly or those allergic to the vaccine—would be protected against HPV and related cancers. 

“The way to protect them is to surround them with a sea of immunity,” Gumel said. 

The authors showed that while expanding Pap test coverage may only offer marginal benefits, strategies that promote safer sex practices, like condom use, would be very effective in curtailing the burden of HPV and related cancers in communities. 

Now, Park is tweaking the model to explicitly account for the contact dynamics of men who have sex with men, as well as other high-risk groups, such as female sex workers. 

At a conference talk last year in South Korea, Park connected with researchers who work closely with Korean public health agencies. They showed strong interest in sharing data and potentially using the study to improve NIP. She added that the findings are applicable around the world—including in the U.S. 

“We could use different data to compare the lessons learned about HPV to the U.S.,” Park said. “Can we do the same thing? Will the same set of intervention strategies work effectively here?” 

Gumel sees reason to try. He reckons that with the 95% effective Gardisil-9 vaccine offered in the U.S., around 70% coverage would be sufficient to achieve herd immunity.

“We do not have to be losing 350,000 people globally to cervical cancer each year,” Gumel said. “We can see an end to HPV and HPV-related cancers if we improve the vaccination coverage.”

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UMD mathematics Ph.D. candidate Hyunah Lim co-authored this article with Gumel and Park.

The paper, “Mathematical Assessment of the Roles of Vaccination and Pap Screening on the Burden of HPV and Related Cancers in Korea,” was published in Bulletin of Mathematical Biology on December 3, 2025.

This research was supported by the U.S. National Science Foundation. This article does not necessarily reflect the views of this organization.