WASHINGTON: The World Health Organisation said on Friday it’s ready to use a new vaccine to combat Ebola while in the United States authorities anno­unced their first success in treating a patient.

In a tweet to the media, WHO Assistant Director General for Health Systems and Innovation Marie Paule Kieny said Ebola vaccines could “be available for efficacy trials” in accepted countries in West African countries in December this year, a month earlier than expected.

In another tweet, she said that pharmaceutical companies developing the vaccine had “committed to ramp up capacity” to provide “millions of doses” by the middle of next year.

In the United States, authorities announced that Nina Pham, one of the two nurses infected with Ebola, was declared virus-free.

She walked out of a hospital near Washington, DC, on Friday, “smiling and unasisted”.

“Although I no longer have Ebola, I know that it may be a while before I have my strength back,” 26-year-old Nina Pham said at a news conference.

The two nurses were infected with Ebola while treating a Liberian Ebola patient at a hospital in Dallas, Texas. The patient, Thomas Eric Duncan, died on Oct 8.

US health officials said three other Americans who contacted the virus while working for a Christian missionary organisation in Liberia have also recovered.

Published in Dawn, October 25th, 2014