Dengue vaccine final trial results look promising

The French drugmaker Sanofi's vaccine division, Sanofi Pasteur, had been carrying out research on the fastest-growing tropical disease over the past two decades.

Its final clinical trial was conducted on 20,875 children aged 9-16 years old across five countries in Latin America - Brazil, Columbia, Honduras, Mexico and Puerto Rico.

The results show the vaccine cuts the risk of hospitalisation by 80.3 percent after a three-dose vaccination schedule. It is also shown to be safe and provides high protection against dengue haemorrhagic fever.

The Latin American trial results indicated a 50.3 percent efficacy against serotype 1(ST1), 42.3 percent against ST2, 74 percent against ST3 and 77.7 percent against ST4.

Although the results show a weak rate against serotype 2, Sanofi was positive that the vaccine could be the best chance against the mosquito-borne disease.

The availability of the vaccine is in line with the World Health Organisation’s target of reducing morbidity by 25 percent and mortality by 50 percent by 2020, said Dr Muruga Vadivale, the Senior Medical Director of Dengue Medical Affairs for the Asia-Pacific Region of Sanofi Pasteur.

"We have to bear in mind that there is currently no treatment for dengue, and no vaccination or protection against the disease. Nearly half the world’s population are at risk. One person is hospitalised every single minute, every year.

"As a medical professional, I am very excited about the results. For the first time ever, after 20 years of research and development, dengue is set to become a vaccine preventable disease," the Singapore-based Dr Muruga told Bernama when contacted Wednesday.

On July 11, Sanofi announced in the reputable medical journal The Lancet, that its dengue vaccine had passed phase III clinical trials in Southeast Asia, one of the last stages of tests for a drug before it can be put on the market.

The clinical trials carried out on 10,275 healthy children aged 2-14 years old in Malaysia, Indonesia, the Philippines, Thailand and Vietnam showed the vaccine reduced dengue by 56.5 percent in the vaccinated group compared with the control placebo group, as observed during 25 months of active surveillance.

The data also showed good serotype specific protection, with better protection shown against DEN3 and 4 (75 percent). However, as with the Latin American trials, the vaccine showed less protection against DEN1 (50 percent) and least to DEN2 (35 percent).

It is 88 percent effective against dengue haemmorhagic fever.

Malaysian virologist Emeritus Prof Datuk Lam Sai Kit viewed positively the consistent results of the clinical trials.

"Although the full details will not be available until the full publication is out, we can gauge that the vaccine has passed the safety test and that it offers protection against all four serotypes to varying degrees.

"Cutting down by half the number of people getting infected, reducing the hospitalisation rate by two-thirds and thus reducing cost, and preventing severe dengue by a similar amount (88 percent in Asia) are important findings.