A prominent American health organization has issued a report predicting that up to 1.4 million people could be infected by the Ebola virus by next January if preventive measures do not prove effective soon.

In its weekly Morbidity and Mortality reports released Tuesday, the US-based Centers for Disease Control and Prevention(CDC) stated that, under the worst-case scenario, if “interventions don’t start working soon, as many as 1.4 million people could be infected by January 20.”

The development came shortly after another report on the worsening epidemic in Africa by the World Health Organization (WHO), which estimated in an article in The New England Journal of Medicine that Ebola cases in the worst-hit African countries will extend to more than 20,000 by early November. The agency, however, did not extend predictions beyond that month.

Commenting on the CDC’s drastic prediction, the WHO’s Director of Strategy Christopher Dye explained, “These kinds of projections are not to say that this is what is going to happen.”

He added, “These projections say, ‘If there aren’t further measures put in place, these are the kinds of case numbers we’d expect to see.’”

The CDC developed a new modeling tool called EbolaResponse to estimate the likely number of future infections.

The report was based on data from August but did not take into account the ongoing international Ebola relief efforts.

In their worst-case scenario, the CDC researchers presumed that the Ebola cases are extensively underreported by a factor of 2.5 in Sierra Leone and Liberia, two of the three hardest-hit countries in West Africa.

Meanwhile, as of September 19, the number of cases tied to the disease in Guinea, Liberia, and Sierra Leone has reached 5, 843. Some 2,800 people have also died of the disease.