Vaccine refusal appeared as early as the 18th century, following the introduction of the smallpox vaccine. The movement gained strong influence in the late 1990s due to a (since-retracted) 1998 report on the alleged link between the measles, mumps, and rubella (MMR) vaccine and autism in children. The said paper by Wakefield et al. caused widespread concern on vaccine safety, which led to a decline in vaccination rates and increased incidence of vaccine-preventable diseases (VPDs). Although subsequent research found no evidence of the MMR vaccine-autism link, vaccine hesitancy is present in a growing minority to this day.
Malaysia has seen a reemergence of VPDs such as diphtheria, measles and pertussis in recent years. Recently in October 2018, the country was saddened by the death of a 14-month-old baby in Johor Bahru due to complications of diphtheria; the toddler’s parents had chosen not to immunise their daughter. Another case of diphtheria involving the death of a two-year-old child in Miri, Sarawak was reported earlier in March 2018. Similarly, the child had not received vaccination against diphtheria since birth.
There were 32 reported cases of diphtheria in the country in 2017, with seven reported deaths. A majority (75%) of the reported cases rose due to vaccine refusal. These figures are a stark contrast to those observed in 2015, in which Malaysia had reported less than five diphtheria cases each year for 11 consecutive years.
The trend in vaccine refusal is especially worrying as the drop in number of vaccinated individuals in a population can negatively impact the herd immunity attained from continuous efforts to immunise the population. This, in turn, increases susceptibility of individuals who cannot safely receive vaccinations (be it due to severe allergy, very young age, compromised immune system or serious illness) to highly contagious and deadly diseases. The infection of an unvaccinated individual increases the risk of infection in other unvaccinated individuals, including those in close contact (e.g. unvaccinated siblings) and also strangers.
The National Health and Morbidity Survey (NHMS) 2016 stated that 4.5% of children 12-23 months of age in Malaysia received incomplete vaccination against preventable diseases in the first year of life. An additional 0.1% had not received any vaccination by their first birthday. The states/federal territories with highest rates of incompletely vaccinated or unvaccinated children aged 12-23 months are Kuala Lumpur (7.3%), Selangor (7.3%) and Labuan (7.1%). The most common reasons given for incomplete vaccination was lack of time (19.9%), child was unwell (17.3%) and cost or transportation constraints (16.6%). Other reasons for incomplete vaccination include vaccine refusal (4.0%), vaccine distrust (2.1%), doubt in halal status (1.3%), concern on possible side effects (2.4%), religious concerns (0.9%) and bad prior experience (0.6%).
In Muslim-majority Malaysia, the halal status of vaccines is under frequent debate due to some vaccines’ production involving porcine elements. However, Deputy Health Minister of Malaysia, Datuk Seri Dr. Hilmi Yahaya has issued a statement that all vaccines provided at public hospitals in Malaysia are guaranteed halal. The halal issue has also been cleared in a media statement made by Director-General of Department of Islamic Development Malaysia (JAKIM), Tan Sri Dato’ Haji Othman Mustapha, clarifying that vaccine usage is permitted for the benefit it confers in preserving human well-being and life. It is also important to note that even vaccines with non-halal status are permissible in emergencies if no halal options were available.
Currently, there are no laws compelling mandatory vaccine administration in Malaysia. Lack of awareness on the dangers of not receiving immunisation against deadly yet preventable diseases may lead to more cases of infection and deaths. Many parents are influenced by inaccurate information from non-credible sources or convinced by close family or friends to reject vaccinations and opt for ‘natural’ alternatives such as homeopathy instead. The low incidence of VPDs due to its eradication by nationwide vaccination programmes might also lead these parents to falsely believe that immunity against these diseases were not essential. Parents have a duty to protect their children’s health and thus are responsible to educate themselves with accurate information from reliable sources, e.g. their healthcare providers.