Information revealed from WHO's internal meetings speaks of delayed communications and hidden data.
Study results also show that two thirds of the patients are men.
The WHO reports a new Ebola outbreak in the Congo, where the fight against the COVID-19 pandemic is already joined by the biggest measles outbreak in the world.
President Trump said the U.S. will leave the WHO, alleging the agency protected China in the early days of the coronavirus pandemic.
During the Cold War, the US conducted experiments with radioactive substances on its citizens.