Two new cases in Guinea, one recovered

The WHO report, published in the New England Journal of Medicine, provides the first results of a long-term study being jointly conducted by the Sierra Leone Ministry of Health and Sanitation, Sierra Leone Ministry of Defence, the World Health Organization and the U.S. Centers for Disease Control and Prevention.

The virus has killed more than 11,000 people in almost two years. “We don’t have the definitive evidence yet”, Margaret Chan, director general of the World Health Organization, told the BBC.

A vaccine against the Ebola virus, developed by Chinese scientists and being tested in Sierra Leone, has proved to be “safe, responsive with very few complaints or side effects”, an official at Sierra Leone’s health ministry has said.

Even after that period, Ebola may be present in the population.

Instead, the preliminary study discovered that the virus can still be found in the semen of survivors for at least nine months after the onset of symptoms.

Researchers aren’t sure why Ebola remains in semen as opposed to other bodily fluids and don’t know if the lingering virus might sicken others. People with Ebola are believed to be most infectious when they are the sickest. Seven to nine months after diagnosis, one-quarter-11 out of 43-still also had traces of Ebola. All men who’d been diagnosed within the previous three months tested positive for the virus.

Johnson & Johnson (JNJ) reported that it has begun clinical trials for an Ebola vaccine in Sierra Leone.

“The abstinence thing isn’t working”, he said, noting there are a number of pregnant women in his district whose partners are Ebola survivors.

Liberia was declared free of Ebola transmission on September 3 after 42 days with no new cases, and Sierra Leone is halfway to the same goal.

“If we don’t find a way of addressing this, we will never stop Ebola”, he said.