Dengue fever epidemic in Cambodia may meet match with new vaccine

Dengue fever epidemic in Cambodia may meet match with new vaccine

The dengue vaccine, developed by Sanofi Pasteur, has been shown effective against three of four known strains of the deadly tropical fever.

Faine Greenwood July 27, 2012

A Cambodian girl walks out of a school with her father in Phnom Penh on July 18, 2012. (TANG CHHIN SOTHY/AFP/Getty Images)

Dengue fever may soon meet its match: a new vaccine has been shown to perform well against three of the four known strains of the virus, Reuters reported. The innovation could have great impact in nations where the tropical fever is a serious public health concern.

Dengue fever is spread by mosquitos and is colloquially known as "breakbone fever," due to the extreme pain some victims of the virus experience. A threat to nearly 3 billion people worldwide, it is particularly frustrating to treat because there are four different types of dengue virus.

Sanofi SA, a French pharmaceutical company, has reportedly developed the new dengue vaccine, and is currently performing trials.

The Sanofi vaccine, according to the company, has performed well in recent trials in Thailand, and has been shown to be safe. Large-scale trials of the vaccine are now underway in Asia and in Latin America, according to the company, and the US Food and Drug Administration has reportedly granted "fast-track" status to the promising new vaccine.

Cambodia is currently experiencing a dengue fever epidemic that, while less widely publicized than the "mystery" EV-71 outbreak, is still taking a terrifying toll in the small Southeast Asian nation — especially on children.

According to the Phnom Penh Post, dengue killed 60 people in the first half of 2012. The 15,600 reported cases of the disease in the first half of 2012 reveals a rate that has nearly quadrupled compared to the same period in 2011, when 4,604 cases were reported.

Although the epidemic is bad, it's not the worst in Cambodia's history, pointed out Steven Bjorge, team leader for malaria and other vector-borne diseases at the World Health Organization's Cambodia office. A 2007 epidemic killed 407 and infected 39,861, according to the Phnom Penh Post.

"The current dengue outbreak is somewhat worse than the past few years, but less than the last big outbreak year of 2007," said Bjorje. "To speak of a 'bad' outbreak this year in a way lessens the impact that every year is bad, in that 12,000 to 15,000 recorded cases are seen each year."

He added, "An effective vaccine would be a great step forward, and we've been waiting on this development for many years."

However, Bjorje cautioned against undue enthusiasm over the Sanofi vaccine. "The current vaccine was successful in protecting against three of the four serotypes. It requires three injections spread out over months, so it is not a simple vaccine to use."

It also isn't likely to be cheap — a concern for the poor, tropical countries where a dengue vaccine is most needed. "The cost will probably not be small, at least in the beginning," he said.

Global Vaccines Inc. Executive Director Robert Johnston echoed Bjorje's cost-concerns. "While the richest 5 percent of persons, even in poor countries, can afford commercial prices for such vaccines, the remainder of the people (about two-thirds of the world's population) live on less than $2 per day," he said.

"Even if a vaccine is made, and even if it is highly effective, a high cost (as with vaccines for rotavirus and human papilloma virus) will make it inaccessible to the vast majority of those who need it most," he added.

The deadly EV-71 virus — which can cause a severe form of the common childhood ailment hand, foot and mouth disease — hasn't been stomped out in Cambodia yet either, according to the WHO. According to the Phnom Penh Post, out of 85 reported cases, there have been 56 deaths.

A press release issued today by the WHO and the Cambodian Ministry of Health called for enhanced surveillance in public health facilities and a stepped-up health education campaign in Cambodia. About 9,000 kindergarten and primary schools have been closed in Cambodia to combat the virus, the GlobalPost reported earlier this month.

During the last week, according to the statement, a total of 533 cases of hand, foot and mouth disease had been reported to the Ministry of Health from across Cambodia. There were nine confirmed cases of severe EV-71 infection, with three fatalities.