Factors Influencing Intention to Obtain the HPV Vaccine in South East Asian and Western Pacific Regions: A Systematic Review and Meta-Analysis

Since licensing in 2006, there has been poor uptake of the human papillomavirus (HPV) vaccine among the targeted population in the South East Asia Region (SEAR) and Western Pacific Region (WPR). The lower response to HPV vaccination is reported to be due to vaccine hesitancy, which underpins reduced vaccine uptake and is defined as a delay in acceptance or refusal of vaccines despite availability of vaccine services. A systematic review was conducted to identify the studies exploring the relationship between factors and intention for HPV vaccination among women in SEAR and WPR countries. The review also sought to gauge the knowledge, beliefs, and attitude towards the vaccine among women from the WPR and SEAR, as these are fundamental when making decisions about vaccination.

Nineteen descriptive, cross-sectional studies were identified as suitable for qualitative synthesis, and three as suitable for meta-analysis. The geographical distribution of these studies was widespread, with research carried out in China, Hong Kong, Japan, Korea, Taiwan, Singapore, Malaysia, India, Nepal, Thailand, and the Philippines.

Eleven studies reported that more than half of their respondents (range 56.5% - 84.6%) had a positive intention of undergoing the HPV vaccination for themselves or their daughters. More women expressed an intention to have a vaccine (range 60% - 97.8%) if it was offered for free, as reported in four studies. Having a positive intention to vaccinate was significantly higher among women not aware of HPV infection (odds ratio (OR): 1.34, 95% confidence interval (CI): 1.02-1.76) and HPV vaccine (OR: 1.57, 95% CI: 1.26-1.96). It is possible that women in the 'unaware' group possessed limited information (for example, from media sources or friends) and may consider HPV to be a bigger health concern in comparison to those who are more aware of the subject. Some studies have found a drop in HPV vaccine uptake with awareness. This may be considered counterintuitive, but it affirms the multifactorial nature of the decision-making process and underlines the need for assessment of all influential factors. It may be wise to focus on "belief modification" of the public to improve vaccine uptake by targeting information on the importance and safety of vaccines to specific sections of the community. (Less confidence in safety and efficacy of the vaccine negatively affected intention to vaccinate.)

On the other hand, needing more information on HPV-related aspects was shown to have a profound effect in two studies. Lack of information was the main reason why Singaporean and Korean university students refused vaccination. Perceiving the vaccine to be expensive, low perception of contracting HPV infection and cervical cancer, and lack of concrete recommendations from healthcare providers also negatively affected intention to vaccinate.

A woman receiving support from her parents, encouragement from friends or recommendation from a physician is more likely to have the vaccine. Receiving a physician's recommendation or discussing the HPV vaccine with a physician was associated with vaccine acceptance and initiation.

In short, this review suggests that the decision-making processes of women in SEAR and WPR are influenced by the cost of vaccination, perceived efficacy and safety of vaccine, provision of information on vaccination, and awareness about HPV infection and the HPV vaccine.

The researchers write, "There is a need for a more tailored health-promotion program for HPV vaccination. In this, it would be useful that parents and young women understand why HPV vaccination is recommended at a young age, the benefits of taking the HPV vaccine and how it outweighs the risks involved (such as adverse effects), the risk factors involved in acquiring HPV infection, and the efficacy of the HPV vaccine in preventing genital warts and cervical cancer. Abolishing the cultural and religious barriers may be impossible, but pitching the vaccine as a cervical cancer vaccine rather than the HPV vaccine may help improve uptake. In addition, it is recommended that parents and young women be educated on why the HPV vaccine needs to be obtained at a young age rather than later."

It is hoped that this information will be of assistance in devising suitable interventions to improve access and acceptability to HPV vaccination in the SEAR and WPR.