Preventing HPV and Eliminating Cervical Cancer in the Americas

Cervical cancer is one of the most common cancers affecting women globally, leading to nearly 350,000 deaths in 2022, with the majority in low- and middle-income countries. Among the primarily middle-income countries of Latin America and the Caribbean, more than 30,000 women die each year from this cancer caused by infection with the human papillomavirus, or HPV, making it a leading cause of death for women in the region.

While there are several hundred known subtypes of HPV, the number considered to be high risk and associated with the development of cervical cancer is relatively small. Certain strains of HPV, which can be sexually transmitted, are also linked to cancer of the vagina and vulva in women, cancer of the penis in men, and oral and anal cancers in men and women. The vast majority of HPV-related cancers In Latin America and the Caribbean are cases of cervical cancer.

Vaccines to prevent infection with the strains of HPV most likely to progress to cancer have been available since the early 2000s. While nearly all of the countries in Latin America and the Caribbean have introduced HPV vaccines, many have historically faced challenges ensuring widespread access to the products, whether because of cost, low awareness of the links between HPV and cervical cancer, or the difficulties of reaching the target population, typically adolescents between the ages of 9 and 15 who have not yet initiated sexual activity, with multiple shots spaced several months apart. Disruptions to health services during the Covid-19 pandemic also widened gaps in routine immunizations, including HPV immunizations, with regional coverage of the first dose of HPV dipping slightly from 78 percent to 76 percent between 2021 and 2022.

The decision last year by the Pan American Health Organization’s (PAHO) Technical Advisory Group on Vaccine Preventable Diseases to recommend a one-dose regimen may make it easier for countries in the Americas to reach adolescents with HPV vaccine. And with Gavi, the Vaccine Alliance, relaunching its HPV program in 2023, there is considerable international momentum both around preventing infection with HPV and educating the public regarding the links between HPV and cervical cancer.

As the health community recognizes International HPV Awareness Day on March 4 and convenes in Cartagena, Colombia, March 5 to 7 for the Global Cervical Cancer Elimination Forum to reinforce high-level political leadership and commitments on the issue, improving equitable access to HPV prevention, testing and treatment; raising awareness about HPV vaccination programs and building capacity around HPV screening will help ensure access for young people in Latin America and the Caribbean, along with their counterparts elsewhere, to essential cancer prevention tools.

Following the approval of the first HPV vaccines in the early 2000s, several countries in the Latin America and Caribbean region launched HPV immunization programs, providing vaccines to patients free of charge through government-supported programs. Initially, many countries organized services around a recommended three-dose regimen and later switched to two doses following revised World Health Organization (WHO) guidance, while a few countries launched HPV vaccine programs directly with a two-dose protocol. Among the countries offering HPV vaccines, there has been some variability in the age of adolescents targeted for vaccination, with some programs aiming to reach recipients at one specific age, for example, 11, while others have targeted a range of ages, such as 9 to 11, or under the age of 12. The majority of countries in the region providing HPV vaccine started by focusing on girls; however, by 2022, 27 of the 47 countries in Latin America and the Caribbean that had introduced HPV vaccine reported that they were also vaccinating boys. Recognizing that adolescents in many countries do not routinely visit health centers, many immunization programs in the region have worked with educational institutions to deliver HPV vaccines to students at school or during school-related activities. By pooling procurement of vaccine doses for member countries, the PAHO Revolving Fund enables national immunization programs to purchase vaccines at a relatively low price of around $10 per dose.

In 2018, PAHO member countries endorsed the Plan of Action for Cervical Cancer Prevention and Control 2018-2030, with a goal of strengthening HPV prevention, improving screening and precancer treatment, and optimizing cancer diagnosis and treatment to reduce cancer incidence and mortality by one-third before the end of the decade. And in 2020 the World Health Assembly adopted the Global strategy to accelerate the elimination of cervical cancer as a public health problem. The strategy sets vaccination, screening, and treatment targets that, if met by 2030, could avert more than 60 million deaths worldwide from cervical cancer over the next century. Milestones on the road to elimination include ensuring that by 2030, 90 percent of girls are fully vaccinated with HPV vaccine by the age of 15; that 70 percent of women are screened for HPV with a high-performance test by age 35, and again at age 45; and that 90 percent of women with pre-cancerous lesions receive treatment and that 90 percent of women with invasive cervical cancer have a treatment management plan, as well.

In 2023, following decreases in coverage of the first dose of HPV vaccine over the course of the pandemic, PAHO relaunched its Plan of Action for Cervical Cancer Prevention and Control 2018-2030. The same year, recognizing an earlier review by the WHO’s Strategic Advisory Group of Experts on Immunization (SAGE) that noted the evidence that one dose of vaccine was comparable to two doses in protecting recipients between the ages of 9 and 20 from infection with the highest-risk HPV subtypes, along with updated WHO endorsement of an “alternative single-dose schedule,” the PAHO Technical Advisory Group (TAG) recommended that “all girls between the ages of 9 and 14 years receive at least one dose of the HPV vaccine” while noting that people living with HIV and others who are immunocompromised should still receive at least two doses and, when possible, three doses. By September of 2023, 10 of the 47 countries in the region reported that they had already switched to the single-dose schedule for the population between 9 and 20 years old.

While reaching the goal of eliminating cervical cancer depends largely on achieving high coverage of HPV vaccine, screening for HPV infection is also an important tool for prevention. Indeed, in 2023 the PAHO TAG also recommended “vaccination services against HPV should be fully integrated within a comprehensive approach towards cancer prevention to achieve the goal of global cervical cancer elimination.”

Ensuring regional access to reliable and high-quality tools to ensure secondary prevention, or screening, however, has proven to be challenging. Diagnostic options include cytological screening (Pap smear) and visual inspection with acetic acid, both of which look for evidence of cellular changes consistent with cancerous or pre-cancerous conditions. A third choice is HPV testing, which the WHO supports as the recommended screening option. While the Pap smear is the best known screening option in many countries, reports suggest sensitivity of cervical cytology in Latin American countries is between 22 percent and 42 percent, making sole reliance on the test of limited utility outside of centers where women have access to comprehensive care. HPV testing offers the benefit of being able to determine if someone is infected with one of the viral subtypes most likely to lead to cancer, but it remains expensive. Mexico is one of the only countries to have introduced HPV testing in all states and territories for women between the ages of 35 and 64. Other countries, including Argentina, Chile, and Peru have introduced HPV testing at the sub-national level while Brazil and Uruguay have conducted pilot projects to assess opportunities for national implementation. Another benefit of HPV tests is that there are versions that can be self-administered, and enabling women to collect test samples themselves without having to visit a clinic or be examined by a healthcare provider promotes higher acceptance and follow-up. However, an important requirement of successful HPV screening is the presence of well-equipped laboratories that can accurately assess samples for the presence of high-risk HPV subtypes and then communicate results to patients in a timely manner.

At the same time, there is a critical need in the Latin America and Caribbean region to improve education about the importance of HPV vaccination and screening in preventing cervical cancer and to overcome barriers in reaching adolescents, in particular with immunization services. Recent surveys in several countries suggest that while adolescents themselves, recognize that receiving the HPV vaccine is important, they and their families do not necessarily understand the links between HPV and cervical cancer or that having been vaccinated does not exempt a woman from needing to be screened at a later date for HPV. Research shows that people feel more confident about vaccines and their safety when they learn about them from a health care provider, pointing to the importance of working with doctors, nurses and community health workers to engage them in the effort to build awareness and confidence in HPV vaccines. Delivering the HPV vaccines through school-based programs has made it easier in several countries to reach a demographic that does not routinely visit health centers, but for those who are not in school, it is important to offer immunizations in other venues where adolescents congregate, whether markets, parks, or other social venues. Patient advocacy organizations and coalitions of cancer survivors also have an important role to play in communicating with the public about the risks and experience of cervical cancer and can encourage greater uptake of HPV vaccines and testing.

The Cervical Cancer Elimination Forum meeting in Cartagena this week convenes governments, multilateral agencies, and civil society groups to review evidence and make commitments regarding cancer prevention, including opportunities to increase HPV vaccination and boost access to high-quality screening and treatment. It comes at an important moment and builds on considerable momentum. Last fall, the Global HPV Consortium was announced, bringing public and private institutions together to prevent infections with HPV and accelerate progress toward eliminating cervical cancer as a public health threat. The new Commission on Primary Health Care and Resilience launched by PAHO, the World Bank, and The LancetAmericas also offers an opportunity to consider how best to integrate HPV vaccination and screening into routine services in the Latin America and Caribbean region.

As Peru develops plans for hosting the Asia-Pacific Economic Cooperation (APEC) meetings later this year, the government has signaled its intent to build on the APEC Health Working Group’s 2023 report on Cervical Cancer Elimination in the APEC Region and to prioritize HPV vaccination as an aspect of disease prevention and economic stability. And Brazil, which will host the G20 in November of 2024, has indicated a prioritization of “building resilient health systems” and local/regional production of vaccines, medicines, and other outbreak response products in its goals for the G20 presidency.

Determining how best to meet the needs of adolescents with routine immunizations, such as the HPV vaccine, can also pave the way for reaching this critical age group with other kinds of vaccines and disease-preventing products essential for responding to outbreaks and protecting global health security.

Katherine E. Bliss is senior fellow and director with the Global Health Policy Center at the Center for Strategic and International Studies in Washington, D.C.

The author is grateful to Carolina Andrada and Jonah Philipp for their research assistance in the preparation of this commentary.

Katherine E. Bliss
Senior Fellow and Director, Immunizations and Health Systems Resilience, Global Health Policy Center