Original articleAcceptability of a Human Papillomavirus (HPV) Trial Vaccine Among Mothers of Adolescents in Cuernavaca, Mexico
Introduction
Chronic infection with certain infectious agents is the main cause of cancer in developing countries 1, 2 where approximately 25% of cancers in women can be attributed to specific agents (3). Human papillomavirus (HPV) is the causal agent of cervical cancer (4) and other cancers of the anogenital area and is responsible for the majority of the chronic infections associated with cancer in women. It is estimated that at least 50% of women with an active sexual life have a genital HPV infection at some time during their lives (5). Cervical cancer is the second most common cancer in developing countries; the highest rates are reported in Mexico and Central America (6). The fact that infectious agents are the main cause of cancer in developing countries should result in new strategies for the prevention of these malignancies, such as the use of safe and effective vaccines. Prophylactic vaccines against hepatitis B virus (HBV) have proven effective in reducing both hepatitis and liver cancer (7).
Justification for a prophylactic vaccine against HPV infection is based on studies in animal models showing that papillomavirus vaccines can protect against infection and prevent the cancers associated with this virus 8, 9, 10. Phase I–II clinical trials have demonstrated that HPV vaccines are safe and effective 11, 12, 13, 14. Some strategies for primary prevention of HPV infection are sexual abstinence or mutually monogamous sexual relationships between noninfected partners. However, these sexual behaviors are not always realistic or feasible. Another proven strategy for the prevention of other sexually transmitted diseases is the consistent and correct use of condoms; however, their usefulness in preventing HPV infection has not been demonstrated.
The target population for prophylactic HPV vaccines will probably be girls who have not initiated sexual activity; therefore, parental consent must be considered when planning these vaccination trials.
The Universal Vaccination Program of Mexico has had remarkable results, with greater than 95% coverage among children under 5 years of age (15). However, there is no information about the acceptance of parents concerning the use of an HPV vaccine as a preventive measure for cervical cancer in their daughters.
This study was conducted to assess the feasibility of carrying out HPV vaccine trials in Mexico and to evaluate factors associated with the acceptance of such trials. We implemented a population survey to evaluate each mother's acceptance of her daughter's participation in an HPV vaccine trial.
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Methods
From July through September 1998, we conducted a population survey among a probabilistic sample of 880 women between 15 and 49 years of age who reside in the metropolitan area of Cuernavaca, Morelos, Mexico.
Cuernavaca is the capital of the state of Morelos, located in central Mexico bordering the capital city (Federal District) and the neighboring states of Puebla, Guerrero, and Mexico. In 1998, the population of Cuernavaca was estimated at 528,954 inhabitants. Principal economic activities in
Results
Respondents had little knowledge concerning the etiology of cervical cancer. Only 1.9% of the women responded that the main risk factor for cervical cancer is infection with HPV, 25.5% knew of at least one other risk factor, and 72.6% did not know the etiology or attributed it to erroneous beliefs.
Regarding knowledge of the usefulness of a vaccine, 84.2% of participants held a correct perception of its benefits. After receiving an explanation on the possibility of preventing cervical cancer
Discussion
The success of a vaccination campaign depends on effectiveness of the vaccine and on coverage attained, which strongly depends on the public's acceptance of the procedure. Likewise, HPV vaccine trials will be effective only if sufficient numbers of individuals accept the vaccine.
The findings of this study suggest that the two main factors associated with acceptance of HPV immunization among mothers of teenager girls are knowledge of the benefits of a vaccine and perception of risk. Women with a
Acknowledgements
This study was made possible by funding provided by the Mexican National Institute of Public Health. This manuscript was prepared while EL was a visiting scientist at the International Agency for Research on Cancer in Lyon, France.
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