PORT-AU-PRINCE (AP) —  The chief advocates for a cholera vaccination program in Haiti began distributing the vaccine last weekend after a government ethics committee gave approval following months of delay, a project organizer said.

Jonathan Lascher, Haiti program manager for the Boston-based Partners in Health (PIH), said more than 200 trained health workers would administer the oral vaccine to almost 50,000 people outside the western port city of Saint Marc.

Cholera is caused by a bacteria found in contaminated water or food, and can kill people within hours through dehydration. It is easily treatable if caught in time.

A Health Ministry ethics committee initially blocked the campaign because it mistook it for a research project rather than a pilot program that could be expanded throughout the Caribbean nation, Lascher said. The vaccination campaign had been planned to begin in January.

“We're all set to go and there are no more bureaucratic hoops to jump through,” Lascher said by telephone. The ethics committee “understands that it's not a research project.”

The vaccination program comes in the wake of an announcement that  the number of cholera cases has jumped as the country headed into the annual rainy season.

The U.N.'s Office for the Coordination of Humanitarian Affairs said in a monthly bulletin that the new cholera cases were found in the western and northern parts of the country and that Haitian health officials recorded 77 new cases a day for the whole country in early March, when the rains began.

Medical teams were deployed to stem the spread of the disease but their effectiveness has been hampered in part by little coordination and an absence of salaries paid to people working in cholera treatment centers run by Haitian authorities, the U.N. bulletin said.

The new cholera cases came after a steady decline since June last year when aid workers saw peaks of more than 1,000 cases on certain days.

Partners in Health said it saw the number of cases nearly triple from almost 19,000 in April 2011 to more than 50,000 two months later.

PIH and partner Gheskio Center, a Haitian nonprofit supported by the U.S. Agency for International Development, plan to vaccinate almost 100,000 Haitians in the Saint Marc area and in a downtrodden neighborhood of the capital as the rainy season begins and threatens to spread the waterborne disease.

The proposal for a vaccine campaign surfaced soon after cholera emerged in October 2010, when U.N. peacekeepers from Nepal apparently introduced the disease inadvertently, according to several scientific studies. Since then, cholera has killed more than 7,000 people and sickened 530,000 more, health officials say, giving Haiti the highest cholera infection rate in the world.

It seemed obvious that Haiti would benefit from such a vaccine but there were obstacles from the beginning.

Some public health experts questioned the program because it would inoculate only 100,000 people, or one percent of the population and could deplete the world's stock of available cholera vaccine, potentially putting people at risk in other vulnerable places. At the time, there was only one cholera vaccine on the global market. A second wasn't approved by the World Health Organization until September.

The approval was needed so U.N. agencies like UNICEF could procure the vaccine.

There were other concerns about the vaccine. The humanitarian group Doctors Without Borders argued that the money for the vaccine, whose immunity wears off within three years, would be better spent on improving Haiti's inadequate sanitation, a source for spreading cholera.

PIH's co-founder Dr. Paul Farmer countered that the vaccine could be distributed without compromising efforts to develop Haiti's water and sewer system.

The project is expected to cost $1.3 million. The American Red Cross is contributing $1 million of that, said Tamara Braunstein, a spokeswoman for the Red Cross.