The current outbreak began in late September.
The school year was due to start on Monday and no date has been set for term to begin.
Cholera is a water-borne diarrhoeal disease that can kill within hours if left untreated, but is easily cured with oral rehydration, intravenous fluids and antibiotics.
Clean water and sanitation are critical to controlling transmission.
President Edgar Lungu has said he was "deeply concerned" at the spread of the disease, blaming water from shallow wells, unsanitary conditions in residential and public areas and contaminated food.
On December 30, he ordered the military to assist efforts to control the disease.