(CNN) -- The deadliest Ebola outbreak in recorded history has now infected nearly 2,000 people, with more than half of those killed by the disease, the World Health Organization said Wednesday.
Ebola is believed to have infected 1,975 people in four West African countries since the outbreak began this year, and 1,069 of them have died, the WHO said. The numbers reflect the WHO's count as of Monday.
That's an increase of 127 cases and 56 deaths in two days, the WHO said.
The outbreak began in Guinea and has spread to Liberia, Sierra Leone and Nigeria.
The new numbers come as health officials are opening up to the use of experimental treatments and vaccines, since no proven treatment or vaccine exists.
A group of ethicists gathered by the WHO this week unanimously concluded that it is ethical to offer unproven medications to fight the Ebola virus, even if their adverse effects are unknown.
After the panel's decision, Canadian Health Minister Rona Ambrose announced that her government will donate between 800 and 1,000 doses of an experimental Ebola vaccine to the WHO. A "small supply" will be kept at home "in the unlikely event it is needed for compassionate use in Canada," the Public Health Agency said.
The drug, VSV-EBOV, is Canadian-made and -owned, having been developed by the National Microbiology Laboratory.
And after an experimental serum was used to treat two American missionaries and a Spanish priest, Liberia is poised to use the serum on two infected doctors.
The U.S. Food and Drug Administration approved Liberia's request for access to ZMapp, which was created by the San Diego-based biotech firm Mapp Biopharmaceutical Inc. Sample doses of the medicine will be sent to Liberia this week to treat doctors who have contracted the virus, the Liberian government said.
The two Americans who received ZMapp, Dr. Kent Brantly and Nancy Writebol, received the serum after contracting Ebola in Liberia. They were transferred to an isolation unit at an Atlanta hospital and appear to be recovering.
Writebol's husband, David, said his wife tells him that "she is feeling better and getting stronger."
"Each time I talk to her, I get a sense her voice is clearer and brighter," he told CNN's Elizabeth Cohen.
The Spanish priest, Miguel Pajares, contracted the disease in Liberia and was transferred to an isolation unit in a Spanish hospital, where he received the serum. He died Tuesday morning.
Mapp Biopharmaceutical said Monday that its supply of ZMapp has been exhausted. Kentucky BioProcessing, which manufactures a version of the drug, is working to increase production of ZMapp, but the process will take several months, company spokesman David Howard said last week.
Ebola can torment its victims with high fevers, internal and external bleeding, vomiting and diarrhea. It often afflicts multiple organ systems and can kill up to 90% of those infected.
The virus spreads through contact with organs and bodily fluids such as blood, saliva and urine.
CNN's Stephanie Smith, Holly Yan and Jacque Wilson contributed to this report.