INDONESIA

Cautious optimism greets results of Asian dengue vaccine trial

A trial of the most advanced vaccine for dengue fever shows that it reduces the severity of the disease, but offers modest protection for those most at risk.

More than 10,000 children in Asia were involved in the trial, developed by French pharmaceutical company Sanofi Pasteur.

While the tests show some promise, researchers say it will be some time before the vaccine becomes available.

Radio Australia’s Tom Maddocks has the story.

For Dr Rose Capeding, leading the vaccine trial was a particularly personal one.

“My eldest son, who is now doing his medical internship, was hospitalised for dengue a few years ago and I think as a mother it's one of the worst nightmares. The platelet count was 18,000 and he was febrile for seven days and again the fever comes back so it was really a nightmare for me.”

Dr Capeding is an infectious diseases expert at the Research Institute for Tropical Medicine in the Philippines.

She led the clinical trials, which involved more than 10,000 healthy children between two and 14 years of age, across the Philippines, Thailand, Indonesia, Vietnam and Malaysia.

The study found that 56 per cent of the children vaccinated were protected from the disease, the most severe cases of dengue were reduced by nearly 90 per cent and the number of hospitalisations were reduced by nearly 70 per cent.

Unsurprisingly, protection was higher in those who have already been exposed to dengue, suggesting that the vaccine would be most helpful in countries at risk, rather than a vaccine for travellers.

Dr Capeding says the trial in Asia is ongoing and they're waiting for other results from a study in Latin America.

“With the complete vaccine profile maybe the next step is to register the vaccine and I think it will take quite a long process, it depends on the registration requirements or the process in each respective countries. I just hope it will be registered and commercially be available to the population, especially in endemic countries because right now we don't have, there's no specific treatment for dengue, no vaccine for dengue, and it's a major public health problem.”

While this is, to date, the most advanced vaccine for dengue, the study found that it only offers modest protection.

Annelies Wilder-Smith is a professor of Infectious Diseases at Singapore's Lee Kong Chian School of Medicine and she provided a critique on the study.

“I think we need to learn that for diseases like malaria, dengue and also HIV, we need to learn to be content with probably lower efficacy rates than for the previous vaccine preventable diseases. Fifty-six per cent on a public health level is not as bad as one would think. I mean if we can reduce the current 100 million cases of dengue worldwide to half I think that is already a success in some way.”

Q. Are you confident that these vaccines will be commercially viable?

“It's a very complex question. It really depends on the country, on the epidemiological levels of dengue in that particular country and it depends on the final pricing that Sanofi Pasteur will put on this vaccine. So basically in the end it will be more a question of the behalf of economists. So is it going to be a cost-effective vaccine or not. So the need for the dengue vaccine is clear. I think we all agree we need a dengue vaccine. The question where we are still unclear is if the 56 per cent efficacy, will it warrant already introduction into the current dengue endemic areas. Obviously you would want to prioritise for the moment. Those countries with a high incidence of dengue, countries like Thailand, Vietnam, Cambodia etc. and all the countries that can afford the vaccine. I think countries or islands like Solomons, where dengue is not such a major issue, can still introduce a vaccine but it's not of such urgency as countries like Thailand, Sri Lanka, Brazil etc.”

The vaccine's maker is French pharmaceutical company Sanofi Pasteur.

They've invested about 1.9 billion Australian dollars in developing the vaccine and have even built a dedicated factory with capacity to produce 100 million doses per year.

Regardless of the vaccines efficacy, there are questions about how it would be sold and what it would cost.

Sanofi Pasteur says it was "too premature" to discuss the vaccine's potential price.

But for Dr Capeding, it's enough to take to the market.

“For me as a mother, even though the efficacy is more than like 56.5 per cent, I think I will take that as a mother.”

• Asia
• dengue
• vaccine
• epidemic
• Radio Australia