Malaysia drags feet on anti-dengue vaccine Dengvaxia

Oct 5, 2016
Singapore has approved the world's first dengue vaccine Dengvaxia.
Singapore has approved the world’s first dengue vaccine Dengvaxia, but Malaysia drags its feet to make a decision.

The Health Ministry should stop dragging its feet and expedite the approval of the world’s first anti-dengue vaccine Dengvaxia.

Singapore’s Health and Sciences Authority (HSA) has already approved Dengvaxia to be used at Down South, but Malaysia is yet to approve it even though the vaccine was offered a year ago by Universiti Malaya.

The Star reported UM research consultant Prof Emeritus Lam Sai Kit of questioning the delay in approving the Dengvaxia vaccine, pointing out that the dengue situation in Singapore was similar to Malaysia’s.

“The sad thing is that we were offered this vaccine more than a year ago and the ministry is still dragging its feet.

“Why must we always have to follow instead of lead?” asked Dr Lam, who has been involved in dengue virology for over 40 years.

“I feel for those who suffered from dengue, and more so those who succumbed to it. How much longer to wait? How many more cases and deaths before they make a stand?”

Dr Lam was a central figure in the discovery of the Nipah virus in late 1990s and instrumental in developing in-house rapid diagnostic techniques to detect the dengue virus.

Launched in 2015, the vaccine is backed by the World Health Organisation’s Strategic Advisory Group of Experts.

Singapore aside, Dengvaxia has also been approved for use in Mexico, the Philippines, Brazil, El Savador, Costa Rica, Paraguay, Guatemala, Peru, Indonesia and Thailand.

Previously Health Ministry director-general Dr Noor Hisham Abdullah said the Drug Control Authority under the ministry had convened several meetings to review the data submitted by the manufacturer and would make a conclusion on the registration by mid-2016.

He said with the overall 65.6% efficacy of the vaccine, it would just be an additional tool in the multi-pronged approach to dengue prevention and control.

Asked about the concern over the vaccine’s low coverage and the possibility of severe dengue when a person is infected twice, Dr Lam said: “The age groups recommended by Singapore overcome these concerns. It follows the WHO guidelines.”

Dr Lam, a renowned medical virologist and the founding chairman of Asia Pacific Steering Committee for Dengue Vaccine to Vaccination Programme, added that the HSA’s guideline was clear and specified how the vaccine was to be used and the reasons it was used on selected age groups.

Asked to comment on reports that the vaccine is less effective against the DENV-1 and DENV-2 strains of dengue, which are predominant strains in Singapore, Dr Lam said it was not a perfect vaccine but the data showed that it was good enough to be used alongside the usual vector control measures.

Singapore HSA has approved Dengvaxia following a seven-month expedited review of the potential benefits and risks.

It will be made commercially available in several months’ time.

Manufacturers Sanofi has not yet said how much it will cost, although its global medical affairs head Dr Ng Su-Peing has said that the company’s goal is to make the vaccine “as commercially accessible as possible”.

Studies have shown that overall, the vaccine is effective at reducing dengue by 60%, and reducing severe dengue by 84%.

Against the Den-1 and Den-2 strains – which account for three-quarters of the dengue cases in Singapore – the vaccine’s efficacy is 50% and 40% respectively, compared with 75% and 77% for the other two strains.

The HSA’s decision to approve the vaccine was based on 24 clinical studies carried out by Sanofi Pasteur – the company manufacturing the vaccine – which involved 41,000 people.

The vaccine was approved for use in anyone aged 12 to 45 years, as studies showed that the risk of hospitalisation from dengue was reduced in those above 12 years old.

But studies also showed that the vaccine was not very effective in those aged above 45.

The HSA said it was prepared to revise its age guidelines when more data is available.

Importantly, the vaccine was also 81% effective in people who had already had a dengue infection previously, compared to 38% in those who had never had the virus.

Younger children who had never had dengue also ran a higher risk of hospitalisation if they contracted the virus after being vaccinated, although this was not seen in older children.

The HSA therefore advised those who have not had dengue to speak with their doctors on whether or not they should get the vaccine.

Singapore Health Ministry does not recommend rolling out this dengue vacine as a national programme as it would not be a clinically and cost-effective means to tackling dengue infection in the republic.

This means that subsidies and Medisave cannot be used to pay for vaccination.

Professor Ooi Eng Eong, who is deputy director of the emerging infectious diseases programme at Duke-NUS Medical School, said: “The impact vaccination would have on the overall incidence of dengue in Singapore would depend tremendously on the number of people who become vaccinated.

“The larger this number, the greater impact vaccination would have on reducing the number of dengue cases in Singapore,” said Prof Ooi, who is also a scientific advisory board member on dengue for Sanofi.