Parental Intention to Vaccinate Adolescents with HPV Vaccine in Selected Communities in Ibadan, Southwest Nigeria: An Application of Integrated Behavioral Model

"[I]nvestigating the intention of Nigerian parents to vaccinate their adolescents with HPV vaccine can...provide useful information which can be used in the design of the HPV vaccination program with a target for a high uptake of the vaccine when it is rolled out in the future."

Nigeria has the highest population of adolescents in Africa and a strong history of vaccine hesitancy. These and other factors increase the importance of behavioural research in Nigeria about human papillomavirus (HPV) vaccination, which is most effective for the prevention of cervical cancer when it is administered before sexual debut. This study investigated the intention of parents in five selected communities to get their adolescents vaccinated with HPV vaccine in Ibadan, Nigeria, using the Integrated Behavioral Model (IBM).

The research described here is part of a larger study that investigated acceptability of the HPV vaccine for adolescents by stakeholders in Southwest Nigeria. Since the HPV vaccine was not yet included in the routine vaccination schedule in Nigeria as of this writing, the study assumed parental intention would closely predict the actual uptake of this vaccine when it becomes routine. Attitude (divided into experiential and instrumental attitudes), perceived norms (made up of injunctive and descriptive norms), and personal agency (consisting of perceived control and self-efficacy) are used to determine the intention to perform a behaviour in IBM.

The findings from the larger study's quantitative data, gleaned from interviews with 678 parents, are presented here. Almost all of the parents (96.8%) had the intention to vaccinate their adolescents with HPV vaccine. This intention was significantly correlated with experiential attitude (the feeling associated with the performance of a behaviour: r = 0.74, p = <.01), instrumental attitude (the attribute that is associated with the performance of a behaviour: r = 0.33, p = <.01), injunctive norm (what the people in one's social circle expects of one's behaviour: r = 0.39, p = <.01), descriptive norm (what the people in one's social circle are doing: r = 0.32, p = <.01), perceived control (the ability to carry out a behaviour in the presence of challenges and barriers: r = 0.32, p = <.01), and self-efficacy (the self-confidence that one can perform a behaviour: r = 0.46, p ≤ .01). A higher proportion of parents older than 65 years significantly had no intention to vaccinate their adolescents with HPV vaccine.

Intention to vaccinate adolescents with HPV vaccine was predicted by experiential attitude (odds ratio (OR) = 0.88, 95% CI: 0.80-0.95), personal agency (OR = 0.22, 95% CI: 0.15-0.29), and injunctive norm (OR = 0.08, 95% CI: 0.02-0.13).

Reflecting on the findings, the researchers note that the high proportion of parents who had the intention to vaccinate their adolescents with HPV vaccine exceeds that found in most other studies. Although the reason for this is not clear, the researchers point to the presence of community health development committees in each of these communities, who have the responsibility of mobilising community members for vaccination programmes. These types of committees have been shown to have positive influence on vaccination coverage in Nigeria. Also, one of the differences between this study and earlier similar research is that the parents in the current study were given details about HPV, HPV vaccine, and cervical cancer before they were interviewed to avoid confusion with other disease conditions. Their responses were thus perhaps a truer reflection of what they thought, as compared to earlier studies that found misconceptions about these concepts in many countries (e.g., confusing HIV with HPV in South Africa).

The researchers discuss possible implications of the different predictors of vaccine intention found in the study. For example, the strong influence of the parents' social circle in their decision about vaccinating their adolescents highlights the importance of community behavioural change in this type of setting, where communal living is the norm.

A notable aspect of this study is the fair representation of fathers (about a third of the parents) compared with most studies, where fathers are either totally absent or are very few. Most African countries are patriarchal, so, excluding men from HPV vaccination or cervical cancer research will be counterproductive, because they are either the sole or main decision makers in their families. Outputs from such research may be irrelevant, because the sociocultural context in which healthcare decisions are being made was not considered in their design. Another strength is the use of elicitation interviews among the community members to develop the survey instruments based on the constructs of IBM. This step ensured that the content of the questionnaire was familiar to the parents, as their culture and beliefs were taken into consideration (in contrast to the Health Belief Model, which has a more individualistic lens).

In concluding, the researchers outline some future research directions, such as comparing the actual uptake of the vaccine when it becomes routine to the current findings. In addition, the reasons for the reluctance of older parents to vaccinate their adolescents can be investigated so that interventions to increase their intention to vaccinate their adolescents can be designed accordingly. The precise reasons for the high number of parents with the intention to vaccinate their adolescents with HPV vaccine also need to be explored.