Liberia discharged its last confirmed Ebola patient on Thursday, as it reported for the first time in nine months it had gone a full week without any new infections.
Beatrice Yordoldo left the Chinese-built Ebola treatment unit (ETU) in the Paynesville suburb of the capital Monrovia to cheers from healthcare workers, government officials and aid workers.
"Today I am very grateful to the almighty God and the Chinese ETU, and all of the Liberian nurses that are working with them. I did not know I could make it," she said.
The country "reported no new confirmed cases" during the week to March 1, the World Health Organization (WHO) said in a report late Wednesday.
"This is the last confirmed Ebola case in our country," deputy health minister Tolbert Nyenswah told reporters as Yordoldo was given an emotional send-off.
Almost 24,000 people have been infected with the virus since December 2013, all but a handful in Liberia, Guinea and Sierra Leone, and 9,807 of them have died, according to (WHO).
Of those, 9,249 cases including 4,117 deaths were registered in Liberia, which six months ago was reporting more than 300 new cases each week.
At the height of the epidemic in a country whose health infrastructure had been ravaged by back-to-back civil wars, overflowing health clinics had to turn people away, often to die in the streets.
But a huge national and international response helped stem the spread.
Of 45 samples tested nationwide last week, none were positive, the WHO said, adding that it was first time there had been no new confirmed cases since May 26, 2014.
- Significant increase -
The outlook was more worrying in Guinea and Sierra Leone, which jointly reported 132 new confirmed cases last week.
Sierra Leone, which counts the most cases in total at 11,466, including 3,546 deaths, registered 81 new confirmed infections last week, up from 65 the week before.
Transmission in the country "remains widespread", the WHO warned, pointing out that new cases had emerged in eight different districts across the country, with rising numbers in Freetown, the Western Rural district and in the northern district of Bombali.
The outbreak in Bombali was reportedly linked to a cluster of cases in the Aberdeen fishing community in Freetown, and WHO said efforts were underway to track over 2,000 contacts associated with that cluster.
The 51 new confirmed cases registered in Guinea last week also marked a significant increase on the 35 new cases reported during the previous seven-day period.
The country, which in total counts Ebola 3,219 cases and 2,129 deaths, also saw a marked hike in new cases in the capital Conakry and in nearby Forecariah, WHO said.  
Massive efforts and funds have been poured into the fight to rid the three west African countries of the Ebola scourge, and a main focus has been to ensure that all those infected are isolated and cared for in treatment centres.
Ensuring safe burials of the highly contagious bodies has also been a priority.
- Vaccine trials -
But both Sierra Leone and Guinea continued to see high numbers of people dying of Ebola in their communities, "suggesting that the need for early isolation and treatment is not yet understood, accepted or acted upon", WHO warned.
More than half of the 32 confirmed Ebola deaths in Guinea last week happened in the community, rather than treatment units, while 16 percent did in Sierra Leone.
Unsafe burials also continue to be a problem in the two countries, with 16 registered last week alone.
The first large-scale trial of an Ebola vaccine will begin in Guinea at the weekend, the WHO said Thursday, weeks after a similar test kicked off in Liberia.
The Phase III testing of the vaccine -- one of two that are in the most advanced stages of development -- aims to ensure it provides protection against the virus.
There is no licensed treatment or vaccine for Ebola, and the WHO has endorsed rushing potential ones through trials in a bid to stem the epidemic.
Researchers have said that it remains unknown what level of immune response is needed to protect humans from Ebola, which causes often fatal haemorrhaging, organ failure and severe diarrhoea.
"If a vaccine is found (to be) effective, it will be the first preventive tool against Ebola in history," WHO chief Margaret Chan said in a statement.