BRASILIA, Brazil — On March 10, the Brazilian government took its first steps toward a nationwide mitigation of suffering triggered by the human papillomavirus (HPV), the world’s most common sexually transmitted infection and frequent cause of cervical and other cancers.
The World Health Organization’s (WHO) far-reaching advisory regarding HPV states that “most sexually active men and women will be infected at some point in their lives and some may be repeatedly infected”–a foreboding prediction that is rare in its scope.
HPV and Cervical Cancer: A Global Burden
HPV manifests itself in more than 100 different types, 13 of which are “high-risk” varietals that cause cervical, throat or anogenital cancers in men and women. Because HPV testing for these high-risk types is disproportionately available in developed countries, the scope of HPV infection worldwide is difficult to quantify. For reference, over 79 million Americans are currently infected with HPV, a burden that increases by 14 million annually.
Two HPV types, 16 and 18, cause seven out of 10 cervical cancers and precancerous growths. Types six and 11 (and a handful of others) cause highly infectious but benign symptoms such as genital warts.
Cervical cancer is second only to breast cancer as the most frequent cause of cancer in women. An estimated 270,000 women lose their lives each year due to complications from the disease, which ranks cervical cancer among the top three killers of women globally.
Over 85% of cervical cancer deaths occur in developing nations.
HPV Transmission and Vaccination
Infection with one of the scores of types of HPV typically occurs following the onset of sexual activity (penetrative sex is not a pre-requisite for infection with HPV, a notable distinction from the more familiar infection route of HIV).
Because the majority of HPV infections are asymptomatic (a surprising 90% of infections clear up within two years without intervention) pinpointing initial infection and preventing future transmission is both an individual and a public health challenge.
The HPV vaccine plays a key role in avoiding health consequences of infection with HPV, since it is the only truly preventative weapon in the arsenal of organizations like the Center for Disease Control (CDC) and WHO. Condom use and mutual monogamy lower, but do not eliminate, infection risk–and cervical cancer screenings merely retroactively identify instances of deteriorating health in HPV-infected persons.
Currently, two vaccines (Cervarix and Gardasil) have been Food and Drug Administration-approved for effectiveness against diseases caused by two cancer-causing types of HPV, 16 and 18. The vaccines are administered in three-dose regimens and are given as injections.
Gardasil is licensed for use in males and is quadrivalent (as opposed to bivalent) protecting against four total strains of HPV rather than the two covered by Cervarix.
A Problematic Cohort: Challenges to Vaccine Administration
The CDC recommends that all 11-year-old and 12-year-old boys and girls receive the full vaccine regimen of three doses (young men and women who did not receive the vaccine during the ideal preteen years can receive it through ages 21 and 26, respectively). Though the target age ranges are intended to nip HPV in the bud “long before any sexual activity with another person begins,” public health organizations have struggled with widespread misinformation regarding the vaccine’s side effects and its potential impact on the onset of sexual behaviors in preteens.
A 2010 study form the University of Massachusetts Medical School and the CDC found that over 30% of parents of 13-17 year-old girls refused or delayed vaccination. The study, which drew from U.S.-specific data as reported in the 2010 National Immunization Survey, found that refusal or delay was more likely in higher income households due to misconceptions of the vaccine’s medical necessity.
Internationally, HPV vaccination is similarly challenging, though, for unique reasons.
A Mixed Bag of Success
Australia’s 2007 vaccination program was the first to reach a national audience. The school-based government initiative vaccinated girls between 12 and 13 years of age and was followed by two other vaccination programs in 2009.
Cooperation with schools led to a positive result: 75% of girls between 12 and 15 years of age received all three doses. The community-based programs, however, only fully vaccinated approximately one-third of women 18-19 years old, and 20-26 years old.
Road Blocks to Vaccinations in the Developing World
Routine preventative health care for adolescents is uncommon in many developing nations; providing services to adolescent girls often requires the development and implementation of a sustainable infrastructure where none exists.
Cost has also been a determining factor in vaccine availability, though the GAVI Alliance has opened the door for developing nations to acquire HPV vaccines at unprecedented low rates. A vaccine that runs close to $100 in the West previously cost $13 in the public sector of the developing world and was out of reach for many. Gardasil doses now hover around a price point of $4.50 each.
Though Gardasil may be in hand, health care providers must see adolescent girls and boys three times to administer the vaccine. Development of programs that ensure full vaccination requires cooperation between schools, parents, health care officials and international agencies such as the GAVI Alliance and WHO.
Brazil: A Tradition of Vaccine Success
On an aggregate level, the Brazilian Immunization Program has excelled in reaching over 90% of children in its over 40-year history. The program mobilizes government health units to deliver high quality national campaigns that distribute state-produced vaccines against influenza, polio, pertussis, measles and more than 10 other diseases.
Though the indicators for these covered vaccines have been heralded by the international community as a gold standard for child care (over 95% of infants completed a three-dose diphtheria vaccine regimen, for example) collaboration between schools and the Brazilian Immunization Program has been infrequent.
Brazil has not historically achieved high coverage rates for adolescents. The recent roll-out of the nation’s HPV vaccination campaign will capitalize on positive outcomes achieved when health ministries and educational systems cooperate.
A Nation in Need
Brazil’s HPV crusade is monumental not only for its logistical and programmatic potential, but also because it “is in the most affected quartile of the world” for many cervical cancer statistics. Though breast cancer tops cervical cancer in terms of incidence, cervical cancer kills more Brazilian women between the ages of 15 and 44 than breast cancer does.
Approximately 14% of Brazilian women are infected with HPV. Annually, over 18,000 women are diagnosed with cervical cancer and nearly 8,500 are killed as a result of the disease.
In 2012, Dr. Marc Steben of Quebec’s National Public Health Institute described the status of HPV infection in Brazil as “very sad” and warned the nation that “[not]taking a stance forward against cervical cancer [would be]perpetuating sexual health inequities for Brazilian women… and the Brazilian society as a whole.”
Brazilian Government Moves Forward
Steben’s foreboding prediction for the state has been heeded. Health Minister Arthur Chioro and colleagues will administer the entire three doses of HPV vaccine at public and private schools in three stages through 2016, until 80% of Brazilian girls between 11 and 13 years of age are covered (over five million individuals total).
The GAVI Alliance recognizes the HPV vaccine as a key component of their effort to bolster adolescent health services and protect women from the debilitating disease that is cervical cancer. The development of vaccination programs provides an opportunity for educators and health workers to collaborate and synergize “nutrition, HIV education, sexual and reproductive health.”
Maria Blair, National Vice President of the American Cancer Society, applauds GAVI’s dedication to guarantee vaccine availability to sub-Saharan Africa, Asia and Latin America in the next few years. She views these measures as “an unprecedented opportunity to… [secure]a brighter future for women and girls, who are the backbone of their families and communities.”
In a few short years, the political, educational and health prognosis for women in developing nations may undergo drastic changes for the better as a result of Brazil’s recent vote to curb HPV infections.
Sources: CDC, GAVI Alliance, ICO Information Center on HPV and Cancer, Jornal brasileiro de doenças sexualmente transmissíveis, National Prevention Information Network, PLOS ONE, World Health Organization, World Health Organization, UNICEF
Photo: Huffington Post