A polio and measles immunisation campaign is being launched by the city of Johannesburg and the social development department.
The city said in a statement on Monday the campaign would run between April 29 and May 17 and from June 17 to 28. It would target all children below the age of five.
"The city of Johannesburg has set a target of reaching at least 95% of the 332 585 children living in the city," it said. The city said it was important to bring children in for two rounds of immunisation.
"To protect children against the polio virus, polio drops need to be given twice," it said. "Children who miss the second round will not be fully protected against the polio virus."
Mayoral committee member for health and social development Nonceba Molwele urged parents to bring their children to be immunised.
"Parents and care-givers are urged to participate in the campaign because polio and measles are highly infectious diseases that are life-threatening and often result in long-term damage and disability," Molwele said.