Health

'Unprecedented rise' in cholera outbreaks prompts WHO to switch vaccine strategy

The World Health Organization said on Wednesday it will temporarily suspend the standard two-dose vaccination regimen for cholera, replacing it with a single dose due to vaccine shortages and rising outbreaks worldwide.

UN agency pivoting to one-dose approach due to 'grave state' of vaccine supply

Patients with cholera symptoms sit in an observation centre at a cholera clinic run by Doctors Without Borders in Port-au-Prince, Haiti on Oct. 7. (Odelyn Joseph/The Associated Press)

The World Health Organization said on Wednesday it will temporarily suspend the standard two-dose vaccination regimen for cholera, replacing it with a single dose due to vaccine shortages and rising outbreaks worldwide.

The U.N. agency said "the exceptional decision reflects the grave state of the cholera vaccine stockpile" at a time when countries like Haiti, Syria, Malawi are fighting large outbreaks of the deadly disease, which spreads through contact with contaminated water and food.

As of Oct. 9, Haiti had confirmed 32 cases and 18 deaths from the disease, while many cases were still awaiting confirmation.

"The pivot in strategy will allow for the doses to be used in more countries, at a time of unprecedented rise in cholera outbreaks worldwide," WHO said in a statement on Wednesday.

The WHO's emergencies director Mike Ryan told reporters in a briefing that the change in strategy was a sign of the "scale of the crisis" caused by a lack of focus on safe sanitation and immunization for all at risk.

"It's a sad day for us to have to go backwards," he said.

A mother holds her child diagnosed with cholera in a hospital in Deir el-Zour, Syria, on Sept. 29. The UN and Syria's Health Ministry have said the source of the outbreak is believed to be linked to people drinking unsafe water from the Euphrates River and using contaminated water to irrigate crops. (Baderkhan Ahmad/The Associated Press)

The one-dose strategy had proved to be effective as a response to cholera outbreaks, the agency said, although the duration of protection is limited and appears to be much lower in children.

The disease often causes no or mild symptoms, but serious cases cause acute diarrhea and can kill within hours if untreated.

Cholera cases have surged this year, especially in places of poverty and conflict, with outbreaks reported in 29 countries and fatality rates rising sharply. The WHO also said that climate change means that cholera is a risk in an increasing number of countries, as the bacteria causing the illness multiplies faster in warmer waters.

A cholera outbreak in Syria has already killed at least 33 people, posing a danger across the frontlines of the country's 11-year war and stirring fears in crowded camps for the displaced.

A cholera outbreak in a north Cameroon refugee camp has killed three people and infected at least 36, the UN refugee agency said on Wednesday.

The first case was confirmed on Saturday in the Minawao refugee camp, which hosts around 75,000 people who fled Boko Haram insurgents in neighboring Nigeria.