Brazil became the first South American country Monday to authorize the world's first-ever dengue fever vaccine, which its French manufacturer says has the potential to save hundreds of lives here.

The tropical disease, a flu-like illness carried by mosquitoes, killed 839 people this year in Brazil and infected more than 1.5 million.

The sprawling South American country's decision to allow the new vaccine, called Dengvaxia, is a coup for French pharmaceutical giant Sanofi, which has now gotten the green light from regulators in three countries.

Mexico became the first country to allow the vaccine on December 9, and the Philippines followed suit last week.

Sanofi has requested regulatory approval in 20 countries across Asia and Latin America.

The vaccine is a potential "blockbuster" drug for the company, which estimates it could generate more than $1 billion a year in revenue.
The Brazilian government said regulators must still set a price per dose, a process that takes about three months on average.

A separate review would have to be carried out for the vaccine to be incorporated in the national vaccination plan, a health ministry official told AFP.

Scientists have long been stumped by dengue, which has four separate strains.

Clinical tests -- carried out on 40,000 people from 15 countries -- have found Dengvaxia can immunize two-thirds of people aged nine years and older, rising to 93 percent for the more severe form of the disease, dengue hemorrhagic fever.

Dengue infects as many as 400 million people per year, and the deadliest form kills 22,000 per year, says the World Health Organization.

It was once considered a disease of the tropics, endemic in only nine countries.

But globalization, urbanization, climate change and air travel are helping it to move into more temperate zones. It is now endemic in more than 100 countries.

The WHO says cases have risen 30-fold over the last 50 years, with more than half the world's population potentially at risk.

The 20 countries where Sanofi Pasteur hopes for regulatory approval have a total population of two billion people -- 200 million of them in Brazil.