Progress Toward Implementation of Human Papillomavirus Vaccination --- the Americas, 2006--2010

Cervical cancer is a major cause of morbidity and mortality in the Americas, where an estimated 80,574 new cases and 36,058 deaths were reported in 2008, with 85% of this burden occurring in Latin America and the Caribbean (1). Two oncogenic human papillomavirus (HPV) types (16 and 18) cause approximately 70% of cervical cancers and a substantial proportion of other HPV-related cancers (2). HPV vaccination provides an opportunity to greatly reduce cervical cancer burden through primary prevention of HPV infection. This report summarizes the progress toward HPV vaccine introduction in the Americas, focusing on countries that have introduced the vaccine in national or regional immunization programs. As of January 2011, four countries in the Americas had introduced HPV vaccine. Overcoming issues related to financing and delivery of HPV vaccine remains a key public health challenge to more widespread implementation of HPV vaccination in the Americas.

Two brands of HPV vaccine are available. Both are effective against oncogenic types HPV 16 and 18: a quadrivalent vaccine (Gardasil, Merck & Co., Inc.) and a bivalent vaccine (Cervarix, GlaxoSmithKline). Quadrivalent HPV vaccine is also effective against nononcogenic types HPV 6 and 11, which cause most genital warts. Pre- and post-licensure studies have shown that both vaccines are safe and well tolerated (3,4). Because HPV infections are acquired soon after initiation of sexual activity, HPV vaccine is most effective if administered before onset of sexual activity. The World Health Organization (WHO) recommends a 3-dose vaccine schedule, completed over the course of 6 months, for a likely primary target population of girls within the age range of 9 or 10 years through 13 years (3).

In April 2009, WHO issued a position statement recommending that routine HPV vaccination of females be included in national immunization programs, provided that 1) cervical cancer and/or HPV-related diseases constitute a public health priority; 2) vaccine introduction is programmatically feasible; 3) sustainable financing can be secured; and 4) cost-effectiveness of vaccination strategies in the country or region is considered. Preferably, HPV vaccines should be introduced as part of a coordinated strategy to prevent cervical cancer and should not undermine or divert funding from effective cervical cancer screening programs (3).

Information on HPV vaccine introduction in the United States and Canada was reviewed. Information about Latin America and the Caribbean was obtained through the Pan American Health Organization (PAHO), which, as part of ongoing cooperation with its member states, monitors HPV vaccine introduction in the region.* Country-specific information was verified by representatives of PAHO member states. As of January 2011, four countries in the Americas had included HPV vaccine in their immunization programs: the United States, Canada, Panama, and Mexico (Table). HPV vaccination coverage varied widely. For the 3-dose vaccination series, coverage among girls aged 13--17 years in the United States was 32% in 2010; in parts of Canada, ≥80% coverage has been reported among girls in the target age ranges.

In the United States, HPV vaccine has been available since 2006. HPV vaccine administration occurs mainly through pediatric and family medicine primary-care providers; a publicly funded program, Vaccines for Children, provides vaccine at no charge to children aged ≤18 years who are uninsured or meet eligibility criteria. Coverage rates have increased each year since introduction in 2006. In 2010, overall coverage among girls aged 13--17 years was 48.7% for ≥1 dose of HPV vaccine and 32.0% for 3 doses (5).

In Canada, HPV vaccine has been available since 2006. School-based HPV vaccination programs delivered by public health agencies began in 2007, and all provinces and territories had publicly funded programs in place by 2009 (6). Year of introduction, target age groups, and dosing schedules varied across provinces and territories; however, all offered HPV vaccine, free of charge, to girls in at least one of grades 4 to 9 (ages 9--15 years) (6). Ten of the 13 jurisdictions offered the vaccine to more than one grade as part of a time-limited catch-up program (7). Although most provinces and territories followed a 0-, 2-, 6-month dosing schedule, Quebec implemented a different approach; the first 2 vaccine doses were administered in grade 4 (ages 9--10 years), and the third dose in grade 9 (ages 14--15 years) (7). In September 2010, British Columbia also began using an extended dosing schedule. Series coverage varied nationally among jurisdictions that reported, with a range of 80% to 85% in the Atlantic (eastern) provinces to 51% in Ontario, after the first year of the program.

In Panama, the Ministry of Health added bivalent HPV vaccine to the national immunization program in 2008 for a target population of girls aged 10 years (8). Vaccine has been delivered through adolescent health services in both clinics and schools. Coverage rates have improved since vaccine introduction in 2008. In 2009, 1-dose coverage among girls aged 10 years was 89%, and 3-dose coverage was 46% (8). In 2010, 3-dose coverage was 67%.

In Mexico, HPV vaccine was introduced in 2008 to 125 targeted municipalities (comprising approximately 5% of Mexico's population) with the lowest human development index, which were estimated to have the highest incidence of cervical cancer (8). Quadrivalent HPV vaccine was delivered via mobile health clinics to girls aged 12--16 years in these municipalities using a 0-, 2-, 6-month dosing schedule (8). In 2008, 1-dose coverage among girls in the target age range within these municipalities was 98%, and 3-dose coverage was 81%. In 2009, Mexico expanded its HPV vaccination program to include 182 municipalities with the lowest human development index and changed to an extended dosing schedule that targets girls aged 9--12 years for the first 2 doses, delivered 6 months apart, followed by the third dose 60 months later. Using the extended dosing schedule, 1-dose coverage was 85%, and 2-dose coverage was 67%; 3-dose coverage at 60 months is yet to be measured. In 2011, Mexico's National Immunization Council approved a nationwide expansion of its HPV vaccination program to include school-based vaccination of all girls aged 9 years.

Reported by

Andrea S. Vicari, DVM, PhD, Lara G. Dilsa, Pan American Health Organization. Shelley Deeks, MD, Surveillance and Epidemiology, Ontario Agency for Health Protection and Promotion, Ontario, Canada. Susana P. Cerón Mireles, MD, Mirella Loustalot Laclette San Román, MD, Raquel Espinosa Romero, MD, National Center for Gender Equity and Reproductive Health; Maria del Carmen Domínguez Mulato, MD, Vesta Richardson López-Collada, MD, National Center for Child and Adolescent Health, Ministry of Health, Mexico. Yadira de Moltó, MD, Itzel S. de Hewitt, Ministry of Health, Panama. Mona Saraiya, MD, Div of Cancer Prevention and Control, National Center for Chronic Disease Prevention and Health Promotion; Terri Hyde, MD, Global Immunization Div, National Center for Immunization and Respiratory Diseases; Lauri E. Markowitz, MD, Eileen F. Dunne, MD, Elissa Meites, MD, Diya Surie, Div of Sexually Transmitted Diseases, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, CDC. Corresponding contributor: Elissa Meites, [email protected], 404-639-8368.

Editorial Note

HPV vaccines are safe and effective, and HPV vaccination offers an opportunity to reduce the substantial burden of cervical cancer for women in the Americas. Although progress has been made in HPV vaccine introduction in the Americas, only four of 35 (11%) PAHO countries included the vaccine in their immunization programs as of January 2011. Several important challenges to implementation of HPV vaccination in the Americas exist, including cost, competing demands for the introduction of other new vaccines, and limited health-care delivery systems that reach adolescents.

HPV vaccines are among the most expensive vaccines available, and current prices in high-income countries† are not affordable for low- and middle-income countries. As with other new vaccines, international cooperation aims to increase HPV vaccine affordability by reducing the cost per dose. For instance, PAHO's Revolving Fund for vaccine procurement is a mechanism that aggregates vaccine purchases by countries in Latin America and the Caribbean and thus achieves economies of scale. Under this fund, HPV vaccine was first offered in 2010; the price per dose for participating countries in mid-2011 was $14 (U.S. dollars). The GAVI Alliance (formerly the Global Alliance for Vaccines and Immunization) is a public-private partnership that provides financing and programmatic support for vaccine introduction in low-income countries. As of October 2011, GAVI had not committed funds for HPV vaccination, and only three Latin American and Caribbean countries (Guyana, Haiti, and Nicaragua) were GAVI-eligible, limiting the potential impact of this program in the Americas. Access to HPV vaccine at more affordable prices is critical for widespread introduction and long-term sustainability of this vaccine in Latin America and the Caribbean, where most countries are considered middle-income.

Another important challenge for implementation of HPV vaccination is limited experience in health-care delivery to adolescents. Historically, most immunization programs have focused on infant vaccination and therefore are less experienced with accessing and vaccinating adolescents. Some countries in the region have participated in demonstration projects to explore options for vaccine delivery. HPV vaccination projects, including school-based implementation projects, have been piloted in Bermuda, Bolivia, Cayman Islands, Haiti, and Peru. In addition to Mexico, the governments of Argentina, Guyana, Peru, and Suriname have been planning to implement national HPV vaccination programs in 2011. Efforts to identify the most effective and affordable strategies for vaccine delivery continue to be investigated (9). Although some countries are using an extended 3-dose schedule, PAHO/WHO and CDC recommend a 3-dose schedule administered over 6 months.

The pace of global introduction of vaccines can be slow. For example, worldwide introduction of hepatitis B vaccine took approximately 20 years. During the past 4 years, several countries in Latin America have introduced rotavirus and/or pneumococcal conjugate vaccines, marking the first time that new vaccines were introduced in middle- and low-income countries at the same time as in high-income countries (10). Additional strategies are needed to overcome challenges to increasing HPV vaccine introduction, especially in regions with a disproportionate burden of cervical cancers. New opportunities to focus on health issues for women could support prioritization of this vaccine for Latin America and the Caribbean.

References

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