REVIEW ARTICLE
CURRENT ISSUES FACING THE INTRODUCTION OF HUMAN PAPILLOMAVIRUS VACCINE IN MALAYSIA
Benefits of HPV vaccination
Due to the length of time required for malignant transformation, it is likely to be decades before the full impact of HPV vaccination on the incidence of cervical cancer can be determined. A study predicted that the vaccines would reduce the number of cervical cancer cases associated with HPV 16 and HPV 18 by as much as 95%.24 Vaccination could also allow less frequent screening and a later age of screening initiation,24 and reduce other HPV-related diseases, such as genital warts, along with their associated psychosocial and economic burden.
Immunisation of boys and men
Currently the vaccines are only approved for use in females. However, HPV infection is equally common in men and women of all ages. Most HPV vaccine studies have been conducted in women, who are at greater risk of cervical cancer than men are of acquiring anogenital cancers. The HPV types that cause cervical cancer have also been linked with both anal and penile cancers in men, although these are rare.25 Thus the vaccines should protect men from genital warts and anogenital cancers.
The vaccine appears to be highly immunogenic and safe for men as well as women.26 Herd immunity effects of vaccination can protect unvaccinated individuals, thus it has been suggested that both boys and girls should be vaccinated.27 As men may be carriers of oncogenic HPV types,28 vaccinating men could reduce HPV transmission, and potentially lower cervical cancer rates among women. However, some researchers have used mathematical modelling to suggest that vaccination of males in addition to females offers little additive benefit in preventing cervical cancer.24 Efficacy trials in young men are ongoing, and the results should contribute to the debate.
POTENTIAL CHALLENGES TO VACCINATION ACCEPTANCE IN MALAYSIA
In Malaysia, the vaccine received regulatory approval in November 2006. However, there is no data available on the Malaysian public’s knowledge on HPV or attitudes to HPV vaccine. Comprehensive surveys need to be carried out to address this, if the vaccine is to be considered for widespread use. The general lack of knowledge about HPV is a major factor that might adversely affect HPV vaccine acceptability. Generally, studies from other countries show poor knowledge among women of HPV and associated diseases. A British survey revealed that <1% could name HPV as a cause of cervical cancer,29 while just 13% of high-school adolescents in Canada had heard of HPV.30
Numerous studies have evaluated acceptability and attitudes regarding the HPV vaccine, but almost all were carried out in developed nations. The characteristics of the vaccine itself, patients’ knowledge and health beliefs, sexual nature of the disease being prevented, and physician recommendations all strongly influence vaccine acceptability.31
Social stigma
Vaccine acceptability undoubtedly will be maximised by effective communication of risks associated with HPV infection and the benefits of vaccination. However, the vaccine may be contentious due to the sexually-transmitted nature of HPV, which carries the stigma of unacceptable sexual behaviour. Receiving a diagnosis of HPV produced emotional distress, anxiety, fear, sexual problems, concerns about transmission, negative self-image and feelings of stigma.32 Young people may feel that by obtaining HPV immunisation, they would be perceived as being more likely to engage in sexual activity. This social stigma may give rise to uncertainty and hesitation when considering vaccination. In addition, as male involvement in contraception is still unfavourable and unacceptable to some men in our society, it will be a challenge to include men in a vaccination programme that aims to prevent cervical cancer in women.
Parental attitudes and perceptions
Parental acceptance of HPV vaccination is critical since the vaccines are recommended for children and young adolescents before the onset of sexual activity. Children and adolescents rely on their parents for guidance as well as consent for vaccination. Two important factors associated with increased acceptance of HPV immunisation among parents were knowledge of vaccine benefits and perception that their child is at risk of infection.10,33 Due to religious or moral values, some may perceive that their children are at low risk for contracting the infection, and thus believe that vaccination is unnecessary. Parents may fear that vaccination of their children might promote sexuality and result in increased unsafe sexual behaviour. It was found that intention to vaccinate was higher when the vaccine was described as preventing cervical cancer, rather than preventing cervical cancer as well as STI.34 Furthermore, as sexual issues are taboo in many Asian cultures, parents may find it difficult to explain to their children the need for vaccination against a STI. Parents may also be wary of new vaccines with no long-standing track record of safety, and unknown duration of protection. They may prefer to wait until the vaccine has been well established before subjecting their child to it.
