The Democratic Republic of Congo (DRC) declared the end of the yellow fever outbreak in that country today following a similar announcement in Angola on 23 December 2016, bringing an end to the outbreak in both countries after no new confirmed cases were reported from both countries for the past six months.
"We are able to declare the end of one of the largest and most challenging yellow fever outbreak in recent years through the strong and coordinated response by national authorities, local health workers and partners," said Dr Matshidiso Moeti, the World Health Organization (WHO) Regional Director for Africa, commending the unprecedented and immense response to the outbreak.
The outbreak, which was first detected in Angola in December 2015, had caused 965 confirmed cases of yellow fever across the two countries, with thousands more cases suspected. The last case detected in Angola was on 23 June 2016 and DRC's last case was on 12 July the same year.
More than 30 million people were vaccinated in the two countries in emergency vaccination campaigns. This key part of the response included mop up and preventative campaigns in hard to reach areas up until the end of the year to ensure vaccine protection for as many people in all areas of risk as possible. This unprecedented response exhausted the global stockpile of yellow fever vaccines several times.
More than 41 000 volunteers and 8000 vaccination teams with more than 56 NGO partners were involved in the mass immunization campaigns. The vaccines used came from a global stockpile co-managed by Médecins Sans Frontières (MSF), International Federation of the Red Cross and Red Crescent Societies (IFRC), UNICEF and WHO. In the first 6 months of 2016 alone, the partners delivered more than 19 million doses of the vaccine – three times the 6 million doses usually put aside for an outbreak. Gavi, the Vaccine Alliance financed a significant proportion of the vaccines.
A challenging outbreak
The first cases in this outbreak were identified on 5 December 2015 in Viana, Luanda Province, Angola. The outbreak spread to the entire country and to neighbouring country Democratic Republic of the Congo, where local transmission was established in March 2016.
From the start of the outbreak, Angola reported a total of 4306 suspected cases and 376 deaths, of which 884 cases and 121 deaths were laboratory confirmed.
In this outbreak, DRC has reported 2987 suspected cases, with 81 laboratory confirmed cases and 16 deaths.
Emergency doses to reach more people
One of the major achievements of the response to this outbreak was the introduction of an innovative dose-sparing strategy using one fifth of a regular dose of the yellow fever vaccine – a technique approved by WHO's global vaccine expert group to protect as many people as possible from the immediate threat of a major urban outbreak.
WHO supported the Ministry of Health in DRC to vaccinate 10.7 million people in the city of Kinshasa using this dose-sparing strategy as a short-term measure that will provide immunity against yellow fever for at least 12 months and likely longer.
Support to countries continues
In addition to supporting mass vaccination campaigns, WHO and partners continue to provide support to Angola and DRC to strengthen disease surveillance, to control the spread of mosquitoes and engage communities so that they can protect themselves.
Climate change, the increased mobility of people within and across borders from rural to densely populated urban areas, and the resurgence of the Aedes aegypti mosquito are increasing the risk of yellow fever epidemics.
"Yellow Fever outbreaks like the one in Angola and the DRC could become more frequent in many parts of the world unless coordinated measures are taken to protect people most at risk. Therefore we need to implement a strong preventive approach to vaccinate the population at risk across the region," said Dr Ibrahima Socé Fall, WHO Regional Emergency Director.
In response, a broad coalition of partners including WHO recently developed a new strategy calling for the 'Elimination of Yellow fever Epidemics' (EYE) to strengthen global action and integrate lessons learnt from the outbreak in Angola and DRC.
Key components of the EYE strategy include measures to ensure people are vaccinated before an outbreak strikes, increase the number of global vaccine stocks for outbreak response and support for greater preparedness in the most at-risk countries.
The Organization's response to the outbreak has been possible thanks to financial support from the Angolan, German and Japanese Governments, Gavi, the Vaccine Alliance, BioManguinhos, the Central Emergency Response Fund (CERF), the WHO International Coordination Group (ICG) Revolving Fund, USAID and the Contingency Fund for Emergencies.