A mass vaccination campaign against cholera has begun in Mozambique to prevent this deadly disease from turning into a full-blown epidemic. 

Mozambique's Ministry of Health confirms more than 1,400 cases of cholera and two deaths, with most cases in Beira, the city hit hardest by Cyclone Idai.

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The campaign is spearheaded by the World Health Organization and United Nations Children’s Fund. During the coming five days, the two agencies and partners plan to vaccinate nearly 900,000 people in the city of Beira and three surrounding areas.

Oral cholera vaccinations usually involve two doses given seven days apart. But WHO spokesman Christian Lindemeier says the amount of available vaccine is enough for only one dose for each person.

“We are hoping that in the course of the year when things are a bit calmer, a second dose could be given, which then extends, of course, the protection. Right now ... the emergency protection is at least six months," Lindemeier said.

"That is why we would like to follow up within the six months to have a longer protection, because let us not forget the area in Mozambique is highly endemic for cholera anyway.”

Aid agencies note the national vaccination campaign is only one of several approaches being taken to curb the spread of cholera. UNICEF spokesman Christophe Boulierac says of equal importance is the provision of safe drinking water to people throughout the disaster zone.

“The fact that together with the government and our partner DfID (the UK's Department for International Development) we have rehabilitated the water system in Beira for 500,000 people after only one week will now pay off, we think, and will contribute to save thousands of lives in the city just because it is preventing the further spread of the disease,” said Boulierac.

Cholera is an acute diarrheal disease that can kill within hours if left untreated. It is mainly caused by the ingestion of contaminated food and water. The young, the frail and the old are most vulnerable.

Children, in particular, are at great risk. Health officials warn children who contract cholera in the morning could be dead by the evening if they are not immediately treated.