The number of confirmed cases of Ebola virus has risen to 710, including 149 deaths, as the epidemic continues to spread in several parts of the country, government data in Congo has increased.

Recent field reports recorded 21 new cases in the past 24 hours, bringing the total number of confirmed infections as of Friday to this new record, amid a health environment suffering from extreme vulnerability and insecurity that hampers rapid response efforts to combat the disease.

UN warnings and a rare strain that caught the field by surprise

The World Health Organization (WHO) has warned that the virus continues to spread and is heading towards new health zones, amounting to 34 regions distributed between Ituri provinces and North and South Kivu.

The head of the WHO's Epidemiology and Intervention Analysis Unit, Olivier Le Bouland, said in a statement from the city of Beni that infections are being monitored almost daily in new areas, reflecting the expansion of the outbreak and the existence of gaps in high-risk areas, especially in the Ituri border region, where displacement, armed conflicts and mining activities are doubling the difficulty of contact tracing and monitoring.

The danger of the current outbreak, according to Le Pollan, is that the virus belongs to the rare "Bondebogio" strain, which is different from the traditional "Zaire" strain that the country has previous experience in dealing with.

A glimmer of scientific hope and vaccines under development

New scientific indications have revealed a glimmer of hope for the development of targeted therapies after discovering the ability of some recovered people to make antibodies that help identify the virus's genetic targets.

Professor Ali Fattoum, a professor of immunology and vaccines from Michigan, told Al Jazeera that understanding how the immune system deals with the virus opens the door to more accurate drugs, pointing out that there are two vaccines under development, one produced by Merck against the Zaire strain that was 80% effective, and the other developed by AstraZeneca in collaboration with the Serum Institute of India to secrete antibodies that target the current "Bundiboggio" strain.

Fattoum stressed that the current challenge lies in quarantine, border control to prevent the spread of the virus to its neighbors such as Uganda, and changing the rituals of dealing with the bodies of the deceased, which are a major source of infection resulting from contact with bodily fluids.

What is the Ebola virus?

Ebola virus is a highly dangerous and deadly haemorrhagic fever that was first discovered in 1976 near the Ebola River in the Congo. The virus is transmitted to humans from wild animals (such as fruit bats and monkeys) and then spread to humans through direct contact with blood, bodily fluids, or secretions of an infected or deceased person.

The incubation period of the virus ranges from two to 21 days, and its symptoms are high fever, weakness, and muscle pain, before it develops into vomiting, diarrhea, and failure of kidney and liver function, and may be accompanied by internal and external bleeding leading to death in the absence of immediate medical care and early fluid support.