UNITED NEWS INTERNATIONAL (UNI) — Two million individuals are set to receive cholera vaccinations in what is being called the largest cholera vaccination drive in history.

The drive comes as a response to a recent string of cholera outbreaks in Africa and will focus on five countries: Zambia, Uganda, Malawi, South Sudan and Nigeria.

As of Monday, at least 12 sub-Saharan African countries have reported active cholera transmission, according to the World Health Organization.

Since early 2018, the World Health Organization says it has worked with health ministries in the five countries to help organize vaccination campaigns in each respective region.

This vaccine drive marks a stark increase in vaccinations of cholera from recent years.

There were 1.5 million doses of cholera vaccines used between 1997 to 2012, compared to the 15 million doses approved for use in 2018 alone.