Mothers’ willingness to pay for HPV vaccines in Anambra state, Nigeria: a cross sectional contingent valuation study

Cervical cancer is the fourth most commonly diagnosed cancer and fourth leading cause of cancer related deaths among females worldwide [1]. Every year, about 528,000 women around the world are diagnosed with cervical cancer and about 266,000 women die from the disease [1]. Cervical cancer ranks as the second most frequent cancer among women in Nigeria, with about 47 million women aged 15 years and older being reported to be at risk of developing cervical cancer. Further, almost 14,089 Nigerian women are diagnosed with cervical cancer and 8240 die from the disease yearly [2]. The health and economic burden of cervical cancer is hence substantial. Cervical cancer deaths often occur in relatively young women, who are raising children, caring for families, and contributing to communities [3].

While cervical cancer screening programmes have been effective in reducing cervical cancer incidence in developed countries, cervical cancer screening in Nigeria is still unpopular [2]. There is currently no organized national screening programme in the country. HPV screening is largely opportunistic, with screening coverage estimated to be around 8.7 % [2]. The two types of vaccines that prevent cervical cancer—GSK’s bivalent HPV vaccine (Cervarix) and Merck & Co. Inc.’s quadrivalent HPV vaccine (Gardasil)—are both licensed in Nigeria. The vaccines are highly effective in preventing persistent HPV infection and subsequent precancerous lesions due to infection with two types of HPV—types 16 and 18—that cause about 70 % of cervical cancer worldwide [2].

High prices have been a major barrier to introducing HPV vaccines in developing countries. The Vaccine Alliance (Gavi) and its partners provide the poorest countries with access to a sustainable supply of new and underused vaccines. Gavi offers access to HPV vaccines for as little as US$ 4.50 per dose and provides support for HPV demonstration programmes and the national introduction of HPV vaccines [4]. The type of support provided however depends on a country’s demonstrated ability to deliver vaccines to young adolescent girls [4]. Gavi’s current vaccine support for Nigeria includes pentavalent, pneumococcal conjugate, yellow fever, meningitis A and measles vaccines, as well as cash support for health system strengthening and immunization system strengthening [5].

Currently, HPV vaccines are purchased ‘out-of-pocket’ and are not included among the vaccines offered for free under the National Immunization Programme (NIP) in Nigeria. Providing free HPV vaccination would further strain the government’s tight health budget. Beside the cost of the vaccine, HPV vaccination requires the development of a new vaccine delivery service for adolescent girls in order to achieve the required doses [6]. This is particularly due to the lack of an existing structure to support the adolescent vaccine delivery. Therefore, even with Gavi’s support, HPV vaccination will require a substantial sum of money for its delivery.

The National Primary Health Care Development Agency (NPHCDA) in Nigeria recently announced the commencement of plans for national HPV vaccination. The plan involves a demonstration project in some selected states of the federation in order to determine cost, acceptance and best delivery method [7]. A financially sustainable HPV vaccine delivery strategy is likely to require user financing to offset some percentage of the actual cost of vaccination. However, the viability of user fees as a financing mechanism for HPV vaccine depends on private demand for the vaccines. Several studies that assessed parental acceptance of HPV vaccination for their daughters in Nigeria reported high levels of acceptance for the vaccine [8–10]. However, to the best of our knowledge, no study has estimated the amount parents are willing to pay for the HPV vaccine. The objective of this study was to assess Nigerian mothers’ willingness-to-pay (WTP) for the HPV vaccine using a contingent valuation method. We also compared the difference between the average WTP value and estimated cost of vaccinating a pre-adolescent girl (CVG) against HPV infection in Nigeria. We focused on mothers because the responsibility of family health in many families mainly falls to the mother [11].

This study aimed to establish how much Nigerian mothers are willing to pay for vaccination of their daughters against HPV infection. The findings showed that the majority of the mothers were willing to pay an average of US$ 11.68 to get their daughters fully vaccinated. Mothers that were previously diagnosed of HPV infection were more likely to demand for the vaccine. Mothers that live in urban areas were less likely to demand for the vaccine. The shortfall needed to augment the cost of vaccination ranges from US$ 6.48 to US$ 24.58 depending on the setting of vaccine delivery (rural or urban) and the unit cost of HPV vaccine (Gavi’s price or lowest price offered to public sector).

This study has useful implications for increasing uptake of HPV vaccine and planning HPV vaccination in Nigeria. Firstly, demand for HPV vaccine is quite high. A total of 91.6 % of mothers were willing to pay for HPV vaccination of their daughters. This is opposed to the fears of HPV vaccine rejection that is speculated on due to cultural and religious sensitivities towards health interventions that target prevention of a sexually transmitted disease [18]. For instance, it has been stated that mothers may be concerned about the vaccine being a ‘license to premarital sex’ [18]. Other Nigerian based population studies have also reported high HPV vaccine acceptance. A study conducted among female health care workers in Enugu, South-Eastern Nigeria reported HPV vaccine acceptability rate of 91.0 % [8]. HPV vaccine acceptance of 74 % among female university students in northern Nigeria has been reported [19]. Also, 70 % accepted vaccination of their daughters in a cross-sectional survey of mothers attending the gynaecology clinic in a Nigeria University Teaching Hospital [10]. High acceptance and demand for the vaccine points to high likelihood of HPV vaccination programme success in Nigeria as fundamental to the success of such programme is the recipients’ willingness to accept the vaccine.

The high demand for HPV vaccines could be capitalized upon to increase utilization of the vaccines in Nigeria. It could be possible to achieve higher vaccine uptake in Nigeria without relying on the government to provide the vaccine. A possible solution to achieving higher uptake of the vaccine is through education of the populace about cervical cancer and HPV vaccination. For example, those diagnosed of HPV infection were more likely to demand for HPV vaccination of their daughters. This group of persons will most likely have more in-depth knowledge of the disease and thus, explains their disposition towards HPV vaccine. A systematic review by Kessels et al. [20] also identified having higher vaccine-related knowledge, having a healthcare provider as a source of information and maintaining positive vaccine attitudes as correlates of HPV vaccine uptake in teenage girls. While waiting for national immunization, interventions that improve understanding of, and positive attitudes toward HPV vaccine could be applied. Educational interventions directed to parents or to adolescents/young adults have been shown to be moderately effective in increasing HPV vaccine acceptance and uptake [21]. Simple educational interventions such as fact sheet about epidemiology and morbidity associated with HPV infection or a few minutes of radio novel about cervical cancer case will help increase vaccine uptake in Nigeria [21].

Another solution to achieving high HPV vaccine uptake is to properly orient health professionals to inform patients and the public about HPV vaccination. Even if HPV vaccination is free under the national immunization programme, uptake of the vaccine will basically depend on whether health professionals are willing to inform adolescent girls about HPV vaccination. Provider-initiated model for improving health service utilization appears to be effective in developing countries. For example, increase in HIV test rates have been attributed to the rapid scale-up of the provider-initiated testing model [22]. The prescriber’s ability to educate their patient population on HPV vaccination must be supported and included as part of the national strategic plan for cervical cancer control. Denmark achieved very high vaccination rates (3-dose coverage of over 80 %) through administration by general practitioners [23].

The second important finding from our study is that co-payment for HPV vaccination could be a viable option to augment the cost of vaccination in a government funded vaccination scenario. HPV vaccination is a costly programme. Even at Gavi vaccine prices, HPV vaccination requires substantial set up costs. Unlike new infant vaccines, which may be added to an existing infant vaccine delivery system, HPV vaccination requires the development of a new vaccine delivery service in order to achieve the required doses [6]. This is particularly so because of: (1) micro-planning defined as planning of vaccination activities at local levels that take into account issues of accessibility, geography, population movements, and cultural characteristics; (2) social mobilization/information, education and communication; (3) higher cold chain equipment requirements for delivery outside health facility; and (4) higher service delivery costs [6]. With health expenditure of US$ 115 per capita and considering other competing health services including nutrition activities and emergency aid [24], it is important to consider other financing options to support HPV vaccination programme in Nigeria.

The caveat to co-payment as an option of financing HPV vaccination is that it may skew the vaccination programme to favour only those that can afford the vaccine. US$ 11.68 could be catastrophic for many to afford in Nigeria considering that about 99 million Nigerians or about 58 % of the population live with less than US$ 1.25 per day [25]. In order to ensure equity balanced programme, HPV vaccination should be provided for free to the poor populace in Nigeria. As a suggestion, a practical way to achieve this is to stratify different secondary schools based on their school fees and offer free vaccination to schools in lowest stratum in school-based vaccine delivery system. Poor populations e.g. rural dwellers could be targeted for free vaccination in outreach vaccine delivery systems.

The WTP value obtained in the study has to be considered in the light of bias that is associated with open-ended elicitation formats and WTP surveys in general. Respondents could have been influenced by the range of values chosen for the payment scale question design rather than their true maximum WTP values. It is also possible that some respondents may have stated no WTP value or very low WTP value especially if they feel that vaccination should be paid by the government. The small sample size of vaccine rejecters could have induced a systematic bias as logistic regression could overestimate odd ratios in studies with small to moderate sample size [26]. Despite these limitations, this is the first study that assessed mother’s WTP for HPV vaccination in Nigeria. The timeliness of this study makes the findings useful for HPV vaccination planning in Nigeria.

The findings showed that Nigerian mothers were willing to pay an average of US$ 11.68 for HPV vaccination of their daughters. At Gavi vaccine price, US$ 6.48 and US$ 7.58 extra are needed to augment the cost of vaccination in urban and rural areas respectively. At the lowest obtainable public sector vaccine price, US$ 23.48 and US$ 24.58 extra are needed to augment the cost of vaccination in urban and rural areas respectively. Demand for HPV vaccine was high and this should be capitalized upon to increase uptake of HPV vaccine. Educating the populace on cervical cancer and provider-initiated vaccination should be promoted as these could increase HPV vaccine uptake. In the event of government funded national vaccination, co-payment could be a feasible strategy to ensure sustenance of vaccination. However, free vaccination should be considered for the poor populace in order to ensure equity sensitive vaccination programme.