September 22, 2011

THE CHOLERA EPIDEMIC in Haiti, which began 11 months ago and quickly became the worst such outbreak in modern history, has exacted a jaw-dropping human toll. So far it is reported to have killed nearly 6,500 people and sickened almost a half-million — 5 percent of the country’s population. And public health experts believe those official figures badly undercount the number of victims.

Here’s another number to consider: $20 million. That’s about what it would cost to vaccinate every person in Haiti against the disease.

To date, almost no one in Haiti has received the vaccine. Sensibly, public health workers have scrambled to identify and treat cholera victims, saving many thousands of lives in the process. At the same time, the country has struggled, in the wake of last year’s devastating earthquake, to improve access to decent sanitation and clean water, shortages of which provided ideal conditions for cholera to spread.

Cholera vaccines are not a magic bullet and are not available in adequate numbers at the moment. The global stockpile is estimated as sufficient for only 200,000 people. Even if manufacturers ramped up production to full capacity, it would take several years to make enough for everyone in Haiti — and doing so would mean neglecting cholera outbreaks elsewhere in the world.

In addition, the vaccine, although relatively effective, hardly ensures immunity, and it generally lasts just two years, after which a booster dose would be required. Some health workers also worry that administering the vaccine, which involves two doses taken at least a week apart, would be difficult.

Still, there are compelling reasons to add vaccinations to the arsenal of public health weapons that has been deployed against cholera in Haiti. After a severe spike in infections during this summer’s rainy season, transmission of the disease has tapered off somewhat, but cholera is still killing Haitians at a rate of at least 10 a day and sickening tens of thousands more each month. Experts believe that cholera, which had never been documented in Haiti, is now endemic there; tragically, it is likely to be a fact of Haitian life for years.

The country’s emphasis must remain on infrastructure and public education, so that more Haitians have access to clean water and understand the critical importance of basic sanitation and cleanliness. There can be no letup in the efforts that have been made to treat cholera victims in slums and rural areas with oral rehydration salts and other interventions that are highly effective in saving lives.

But those efforts should be supplemented with an ambitious vaccination program starting as soon as practicable. A recent study showed that if only 5 percent of the population in the most vulnerable areas were vaccinated, it would cut the number of cholera cases by 11 percent, and if 30 percent of Haitians got the vaccine, it would reduce infections by 55 percent and save 3,320 lives. Surely that would be a worthwhile return on a very modest investment.