Great Hesitation In Adopting Dengue Vaccine

Dengxavia, the world’s first approved dengue vaccine, has been rolled out in parts of Asia and South America—but doubts over its efficacy and potential for causing side effects remain.

AsianScientist (Oct. 10, 2016) – by Joel Adriano – Should countries start vaccinating its citizens against dengue? This is a dilemma countries with huge dengue cases have to grapple with while weighing the use of Dengvaxia, the world’s first approved dengue vaccine.

The vaccine is 65.6 percent effective against dengue, says Dr. Ng Su-Peing, global medical director of Sanofi Pasteur, which produces the new vaccine.

In April, the Philippines became the first country to roll out Dengvaxia, while Brazil launched a similar one last month. Indonesia is also reportedly considering mass vaccinations, along with the Latin American countries of Costa Rica, El Salvador, Guatemala, Mexico, Paraguay and Peru.

But after vaccinating almost half a million school-age children, Philippine health officials under the administration of newly-installed president Rodrigo Duterte halted the dengue vaccination program and proposed a review over fears that the vaccine could cause side effects. Some local doctors also advised to wait for other countries to try out the vaccine first or wait for a better drug to come in.

Dr. Tikki Pang, former World Health Organization director for research policy and a professor at the Lee Kuan Yew School of Public Policy of the National University of Singapore, says two other drug firms are close to coming up with dengue vaccines, though it will probably take two or three years before these become available. He also thinks their efficacy wouldn’t be significantly different from Dengvaxia.

About 390 million people in over 100 countries are affected by dengue each year. Pang says while deaths in terms of percentage aren’t quite high, over 12,000 people dying each year from dengue are still too many.

“Should you wait [for a better drug] at the expense of people’s lives?” he asks. “The current vaccine might not be perfect, but it’s the best we have at the moment. Moreover, it doesn’t prevent countries from shifting to a better vaccine later on once this becomes available.”

What is critical, he says, is for decision-makers to determine the extent of the problem as it might be too costly to implement mass vaccination, and to consider independent scientific evidence.

Interestingly, Pang declined to reveal the cost of the Dengvaxia vaccine, which isn’t readily available outside of government-sponsored vaccination programs. One can only guess that the vaccine doesn’t come cheap—which raises the question if poor countries can afford it.

Pang suggests that governments and drug firms could opt for “advance market commitment,” wherein governments commit to buy the vaccines as early as during the research stage to guarantee some return on investments.

Another suggestion Pang makes is tier pricing, where drugs are sold higher in rich countries to subsidize prices in poorer ones—like what’s happening with hepatitis B and typhoid vaccines.


Source: SciDev.Net; Photo: Shutterstock.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

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