Through frequent door-to-door polio immunization campaigns, South Sudan has vaccinated more than 94 percent of children under age five against the disease, according to the Ministry of Health. The immunization effort has been one of the country's few health success stories since it achieved independence a year and a half ago.
In conjunction with World Immunization Week, taking place this week, thousands of volunteer vaccinators are conducting a four-day campaign, trying to reach as many of the country's 3.3 million children as possible to keep the country polio-free.
Polio a priority
When the country emerged from decades of war in 2005, its health system was devastated. There were few functioning health centres in rural areas, which meant most children went without routine vaccinations against deadly diseases like polio.
Polio vaccination became one of the new country's early priorities, in line with an international effort to completely eradicate the disease by 2013.
The door-to-door effort is critical to the success of the programme, said Gladys Lasu, a health and nutrition specialist with UN Children's Fund (UNICEF), which procures the vaccinations for many immunization campaigns.
"We're trying to eradicate polio in South Sudan," Lasu said. Though there have been no new cases in nearly four years, she said the effort is important so it "can continue being that way."
Four times a year, the health ministry organizes teams of volunteers to fan out across the country and immunize as many children as possible - including children who have already been immunized. Repeat immunizations are not harmful, and universal outreach is easier than trying to identify specific unvaccinated children.
Ahead of the campaigns, organizers launch a media blitz that includes text messages, billboards and radio announcements. Trucks with speakers bolted to the roofs blare announcements encouraging people to bring their children to health centres or make them available for the door-to-door vaccinators.
Moses Ali Bolo is a team leader in the Nyakuron area of Juba. He coordinates 10 teams, who will vaccinate a total of at least 1,000 children every day.
Parents "are responding to the vaccinators," he said. "They are aware of the vaccinators, through the radio. That is why they are turning up."
Anthony Lako, the director of the ministry of health's expanded immunization programme, said immunization uptake - and the polio campaign in particular - have been well-received by the population. "Many areas [have been] reached, but there still are, of course, lots of challenges."
These include the steady stream of South Sudanese who have been returning to the country since it achieved independence in 2011. Many have not been vaccinated.
Lako also said there are areas of South Sudan - particularly Jonglei State, in the country's northeast - that are wracked by violence, making it difficult for vaccinators to reach all households.
Still, the polio campaign seems to be working, with no documented re-emergence of the disease.
Focus needed on other diseases
But the country's broader immunization efforts have not been as successful.
South Sudan's Ministry of Health made immunization a priority in its basic package of health and nutrition services, which was drafted ahead of the country's independence. These included routine childhood immunizations for children under one year old, specifically vaccinations for diphtheria, whooping cough, tetanus, tuberculosis and measles. There are no door-to-door campaigns for these vaccines, but families are encouraged to visit local government health facilities, which are supposed to provide the immunizations.
Yet only 9 percent of children under the age of one in South Sudan are fully immunized, according to the 2012 National Expanded Programme on Immunization Coverage survey. South Sudan remains a priority country for polio vaccination according to UNICEF.
Lako said all health facilities are supposed to vaccinate children, but "some [vaccines] are not given due to issues related to accessibility. Some of the facilities have no human resources. That is why it is not fully implemented."
Still, UNICEF has launched two door-to-door campaigns to fight maternal and neonatal tetanus in the country's southern Equatoria region, according to Lasu. Another effort should follow in August.
The health ministry reports more than half of all women in the country have received two doses of the tetanus vaccine. The World Health Organization (WHO) recommends women receive at least two doses one month apart in the first pregnancy.
The country's health sector has been hit particularly hard by an ongoing austerity budget. At independence, 98 percent of South Sudan's revenue came from oil production, but in January 2012, the country shut down oil production following a dispute with Sudan - whose pipelines the South is dependent on to export oil - over transit fees. Production was re-established this month, but no revenue is expected to come in until late June, at the earliest.
According to WHO, only 5 percent of the nearly $9.5 million spent annually on immunizations comes from the government. That should change soon. During his speech opening parliament on 23 April, President Salva Kiir pledged budget increases for vital sectors, including health.