ADVERTISEMENT

Protecting ourselves from dengue


WHILE Indonesia, the Philippines, Thailand and Singapore have within this past year approved the new vaccine against dengue fever and started to make strides against the deadly disease, Malaysia continues to rely on outmoded mosquito control techniques such as fogging.

Last year, 93,781 Malaysians contracted dengue fever and 217 died, according to the Government’s November update.

Why is it that 13 dengue-endemic countries in Asia and Latin America have so far approved the new vaccine and Malaysia lags behind, despite its high burden of disease? So far, the Government has not been entirely clear on its reasons for delaying the decision.

When the vaccine completed clinical trials in 2014, Deputy Health Minister Datuk Seri Dr Hilmi Yahaya announced that the vaccine would be made available within the public health system by mid-2015.

The Government reversed this decision several months later, apparently unconvinced that the vaccine was sufficiently effective for large-scale use.

Last November, Health Minister Datuk Seri Dr S. Subramaniam justified the continued blocking of the vaccine on the grounds that there is not enough data on how it works in adults.

By this stage and with so many countries now adopting the vaccine, there is now plenty of clinical evidence to answer questions regarding its safety and efficacy.

The clinical trials, which led to the World Health Organisation (WHO) giving the nod to the vaccine, were among the most extensive for any vaccine in history, involving around 30,000 people in 10 countries across Asia and Latin and America (including 1,400 volunteers in Malaysia). The five Asian countries in the study alone constituted 70% of the global disease burden of dengue.

The Asia clinical trial demonstrated that the vaccine resulted in an 88.5% reduction of dengue haemorrhagic fever, the severest form of dengue. Dengue haemorrhagic fever leads to hospitalisation for over half a million people every year, mostly children.

The study also showed a significant reduction of 67% in the risk of hospitalisation due to dengue.

Concerns have been raised by the health minister and others that the vaccine can make dengue symptoms worse for children later infected by the dengue virus.

For this reason, the WHO recommends the vaccine be used for children over nine years and adults living in dengue hotspots – of which there are 145 identified locations in Malaysia, including 107 in Selangor, 23 in Johor and nine in Perak.

This is because the data shows the vaccine works best for those already infected previously by dengue – which in endemic areas includes most older children and adults.

Concerns have also been raised that the vaccine is not effective against the strains of dengue virus most common in Malaysia.

Commenting on the fact that the vaccine is only 50% effective against the most common Malay­sian strain (DENV-1), Universiti Malaya research consultant and virology expert Prof Datuk Dr Lam Sai Kit was quoted in October 2016 as saying that the current vaccine is not perfect but the data showed that it was good enough to be used alongside the usual mosquito control measures and has the potential to significantly reduce the burden of dengue in Malaysia.

The vaccine also offers 75% protection against the other common Malaysian strain (DENV-3).

One can understand the Govern­ment’s caution in committing a large amount of public funds to include the vaccine in the national immunisation programme.

Less understandable is its reluctance to approve it for private use, so that individuals can take steps to protect themselves and their families.

This is the path taken by Singa­pore, which approved the vaccine for private use in October, following a thorough review of the clinical evidence.

The dengue vaccine is not a perfect vaccine, but few vaccines are.

Dr Meer Ahmed, former assistant director of medical services in the Malaysian Army, has pointed out that when the cholera vaccine was introduced, it had only a 30% protection rate. Yet, it was promptly approved by the Government and is still in use today.

There is inconsistency with the way the Government is treating the new dengue vaccine as compared to how it has approved vaccines in the past.

Datuk Dr Musa Mohd Nordin, a renowned paediatrician and neonatologist, has observed that virtually all the vaccines available today in the National Immunisation Programme (NIP) were first made available to private providers.

Vaccines for Hepatitis B, Measles, Mumps, and Rubella (MMR), Haemophilus influenzae B and Human Papilloma Virus were prescribed by private practitioners prior to their inclusion into the NIP, according to Dr Musa.

He has indicated that “others yet to be incorporated into the NIP, e.g Pneumococcal Conjugate Vaccine, Rotavirus, Varicella, Influenza vaccines, etc, are presently widely used by private practitioners while the Health Ministry considers the cost implications”.

Registration of a pharmaceutical product is compulsory before it can be used in Malaysia, but that does not mean people have to use it once it is registered.

Granting registration, the dengue vaccine would give doctors and their patients living in dengue hotspots the opportunity to weigh the available evidence themselves, and make an informed choice.

This choice to use the dengue vaccine should also be presented in the same way that other vaccines not yet incorporated into the NIP, are available to the Malaysian public. Too many undue restrictions will potentially hamper the impact it might have on communities living in those hotspots.

Given the risk to life posed by dengue, it should be their right to protect themselves and their families.

PHILIP STEVENS

Senior Fellow

Institute for Democracy and Economic Affairs

letters , dengue , vaccine

   

ADVERTISEMENT