7 key findings from UN's bungled response to yellow fever

The World Health Organization and its partners shipped more than 6 million yellow fever vaccines to Angola in February to quash an emerging epidemic, yet when they asked country officials the following month what happened to the vaccines, they discovered that about 1 million doses had mysteriously disappeared.

Of the UNagency's shipments that did make it to Angola, some vaccines were sent to regions with no yellow fever cases, while others arrived at infected areas without syringes. In neighbouring Congo, some vaccines weren't always kept cold enough to guarantee they would be effective.

• Yellow fever outbreak a 'serious public health event', WHO says

This lack of oversight and mismanagement has undermined control of the outbreak in Central Africa, the worst yellow fever epidemic in decades, an Associated Press investigation has found.

WHO vowed after its fumbled response to the 2014 Ebola epidemic in West Africa that it would adopt a "no regrets" policy to better manage future disease outbreaks with its partners in other health organizations and national governments. But according to hundreds of pages of internal emails and documents obtained by AP, the U.N. health agency is facing many of the same problems that compromised its handling of Ebola, an outbreak that killed 11,000 people in three West African countries.

Health officials now estimate they will be short millions of doses to fight an epidemic that has also spread to Congo. To date, yellow fever is estimated to have caused upward of 5,000 cases and at least 450 deaths. More than 18 million vaccines have been sent to the continent, far short of the 40 million doses some experts think are needed to contain the outbreak.

Dr. Bruce Aylward, who directed WHO's Ebola response, acknowledged that more changes are still needed to enable WHO to respond quicker to complex emergencies, even though he said the agency has made substantial reforms in the past two years.

"It would be a mistake to think that WHO is now ready," he said. "I think a lot of things are better but I don't think we're there yet."

7 key findings:

1. Amid a critical yellow fever vaccine shortage, more than 1 million doses sent by the U.N. World Health Organization and partners to Angola in February disappeared. Officials complained internally that they suspected the shots were appropriated by local politicians or wound up on the black market.

2. Months later, WHO and partners were still mystified by where the vaccines were being used in the country. In a series of internal calls, health officials complained that shots were sometimes used in areas that had no yellow fever cases, without any explanation. Experts complained that it was "pointless" to approve vaccine plans for Angola since the country was completely disregarding them.

3. An internal draft document sent from WHO's Africa office to its Geneva headquarters in June cited a lack of senior leadership at WHO. It said the emergency outbreak response manager and team in Angola "are unable to lead or positively influence the operational direction and scale of containment efforts."

4. As the outbreak raged, manufacturers sent vaccines that sometimes were not accompanied by syringes, due to poor U.N. management. In Congo, one WHO logistics officer questioned whether the vaccines were being kept cold enough and warned WHO could "hardly guarantee the quality of the vaccine."

5. The sole laboratory in Congo for diagnosing yellow fever closed for weeks after running out of diagnostic materials, leaving officials unable to track the evolving outbreak. Pressured by aid groups to act quickly, WHO's Director-General Dr. Margaret Chan emailed Dr. Joanne Liu, International President of Doctors Without Borders, to detail a number of steps taken to resolve the problem. To avoid bad publicity, Chan asked Liu not to share the email.

6. The continuing outbreak in Angola and its increasing need for yellow fever vaccine has left other countries unable to get requested stocks, compromising their preparedness for a potential outbreak. Faced with growing demands for limited vaccines and a proposal to dilute doses to stretch availability, a senior UNICEF staffer wrote in a June email: "WE HAVE A MAJOR PROBLEM ON OUR HANDS."

7. Officials plan to offer weaker vaccines in Congo this month, despite limited evidence that diluted vaccines would provide sufficient protection in African populations. Instead of the normal vaccine, officials plan to use a version containing one fifth the usual dose. A draft WHO document on the "fractional dosing" included a line that said the strategy should be "forgotten." In a later version, that sentence was deleted.