Ebola: blood serum leads the global race to find a cure

WHO says serum could be available in 'weeks' – but what other Ebola treatments and vaccines are being developed?

LAST UPDATED AT 10:45 ON Wed 22 Oct 2014

Serum extracted from the blood of Ebola victims who survived the virus could be made available to patients in Liberia in the coming weeks, according to the World Health Organization (WHO). 

The body is fast tracking several experimental drugs and vaccines to be ready by January, according to the BBC.

There is currently no proven Ebola vaccine or cure, but several pharmaceutical companies are racing to develop safe and effective methods of treating and preventing the disease.

What is blood serum and how does it work?

Serum is part of blood plasma and, in this case, is taken from a patient who has recovered from Ebola as it contains essential antibodies that can fight the virus. It has proven effective in earlier outbreaks, but the WHO has previously been hesitant to use it widely until stricter safety controls were introduced. Healthcare workers warn that the blood needs to be screened carefully for diseases such as HIV and the serum only be administered by health care professionals.

When will it be ready?

The serum has already been used to treat infected healthcare workers. Earlier this month, William Pooley, the British nurse who recovered from the virus donated his blood to infected healthcare workers in Texas. The WHO expects the serum to be more widely distributed in Liberia, the country worst affected by the outbreak, "within weeks".

Vaccines

Human trials are currently underway for several different vaccines developed by the large pharmaceutical companies GlaxoSmithKline and NewLink Genetics as well as the US National Institute of Allergy and Infectious Diseases. Scientists hope that patients will react to the small amount of the virus and develop immunity against it.

When will they be ready?

The latest announcement from the WHO suggests that a vaccine could pass safety and efficacy tests as early as January next year. However, just last week, GlaxoSmithKline said their vaccine would not be ready in time for the current outbreak as safety trials would not be completed until the end of 2015.

ZMapp

The experimental drug is made up of a cocktail of antibodies harvested from an infected animal's blood and grown in specially-modified tobacco leaves. It works by stopping the virus from entering and infecting new cells. It has been used to treat dozens of healthcare workers, many of whom have gone on to make a full recovery. However, doctors say it is too early to know whether the drug is effective or safe in the long-term.

When will it be ready?

ZMapp takes a long time to produce even in small quantities and all available doses have now been distributed, according to its manufacturers. Supplies of the drug "will not be sufficient for several months to come" the WHO warned recently.

TKM-Ebola

Developed by a Canadian pharmaceutical company, the drug works by interfering with the virus's genetic code and stopping it from producing disease-causing proteins.

When will it be ready?

Human trials were halted earlier this year over safety concerns, but the company recently announced that the US Food and Drug administration had partially lifted the ban, raising hopes that the drug could be made available in the near future.

Ebola: fresh deployment of UK troops to West Africa

21 October 

Soldiers from the Royal Army Medical Corps have been deployed to Sierra Leone as part of the UK's pledge to help fight the Ebola outbreak.

Nearly 100 medics were joined by International Development Secretary Justine Greening, who is travelling to the region to oversee the UK's training centres. The medics will be working alongside 90 military personnel already stationed in the country.

The deployment forms part of the UK's £125m aid package to help the tackle the disease in West Africa. This includes setting up treatment centres, training healthcare workers and sending around 750 personnel to the region along with the Navy's RFA Argus.

"Halting the disease in West Africa is the most effective way of preventing Ebola infecting people here in the UK," she told ITV news.

"I look forward to seeing for myself how British Army medics and engineers, as well as our humanitarian and health workers, are spearheading the UK's efforts to contain and ultimately defeat Ebola."

The outbreak has killed over 4,500 people, mainly in Sierra Leone, Liberia and Guinea.

Ghana's President John Mahama has said that vital medical supplies are finally beginning to reach the worst affected countries. Aid agencies have criticised major airline carriers such as British Airways for cancelling direct flights to the region as it impedes their ability to deliver essential goods and personnel.

European countries have already pledged £400m in aid to help stem the crisis, but the UK is pressing for that amount to be doubled, the BBC reports.

The BBC's international development correspondent Mark Doyle has said that while the UK's contribution is "significant", it has come "very late", as aid agencies had been warning of a humanitarian crisis since April.

Meanwhile, enhanced screening methods have now been extended to Gatwick Airport. Passengers arriving from West Africa face temperature checks, will need to fill in a questionnaire and will be observed for visible signs of the virus.

The measures are expected to be introduced at Eurostar terminals by the end of the week and at Manchester and Birmingham airports in the coming weeks.

Ebola virus factfile

What is the Ebola virus and what are the symptoms?

The World Health Organisation describes Ebola as "a severe acute viral illness". Early symptoms are similar to malaria and include the sudden onset of fever, intense weakness, muscle pain, diarrhoea, vomiting and both internal and external bleeding. There are five known strains of the virus, the one currently spreading across West Africa is known as the Zaire Ebola virus and is one of the most dangerous. Patients who do not survive the disease most often die from blood loss, organ failure or shock.

Where did it come from?

Scientists believe it was initially present in wild animals such as fruit bats living in tropical rainforests in equatorial Africa. The disease spread to humans when they came into contact with the organs, blood or other bodily fluids from infected animals through hunting.

How is it spread?

Ebola is highly infectious. It can be transmitted through contact with the blood, bodily fluids and organs, including skin, of sufferers or through indirect contact with environments contaminated by the disease. The disease can also have a long incubation period, up to three weeks, which allows it to spread rapidly before diagnosis and quarantine can take place.

Is there a cure?

There is no known cure or vaccine for the virus and the disease kills between 25 and 90 per cent of its victims. The fatality rate of the current strain appears to be roughly 70 per cent, according to the latest WHO figures. The only routine treatment doctors can currently offer is palliative care such as rehydration and pain relief.

However, there are various experimental treatments and vaccines currently in development, most notably the zMapp drug which has been given to several healthcare workers who have contracted the disease. It's effectiveness and long-term safety is yet unknown.

What happens to people who survive the disease?

"There is strong epidemiological evidence that once an individual has resolved an Ebola virus infection, they are immune to that strain," according to Dr Bruce Ribner, director of the infectious disease unit at Emory University Hospital in the US. Doctors believe that the antibodies present in a patient's blood could protect them from that virus, but warn they would still be susceptible to other strains.

William Pooley: British Ebola nurse returns to Sierra Leone 

20 October

William Pooley, the British nurse who recovered from the Ebola virus has returned to work in West Africa.

The 29-year old, thought to be the first Briton to be infected with the disease, contracted Ebola while working as a health care volunteer in Sierra Leone. He was flown back to the UK, where he was quarantined and received the experimental drug zMapp and later made a full recovery. 

Pooley said returning to work in a region where over 4,500 people have died from the disease was an "easy decision" to make.

He has said he could not stand "idly by" while more people died. "I chose to go before and it was the right thing to do then and it’s still the right thing to do now," he told The Guardian.

It is still unclear whether or not Pooley is immune to the virus or how long it could last. "They have told me I very likely have immunity, at least for the near future, to this strain of Ebola," he said. "I have also been told it's a possibility that I don't, so I will just have to act as if I don't."

Pooley will join a team of British health care workers from King's College London and three NHS trusts working at a hospital in the capital Freetown.

He urged the West to direct more attention to the heart of the outbreak in West Africa. "The risk of a really damaging outbreak here [in the UK] is negligible. There's an absolute catastrophe happening in another part of the world," he said. "That should be our focus."

In other developments: 
  • Liberian president Ellen Johnson Sirleaf has warned that a generation of Africans were at risk of being lost to the disease, adding that the whole world has a stake in the fight against Ebola.
  • Nigeria has been officially declared Ebola-free, six weeks after the last infection was reported. The successful containment of the virus was due to early detection, a co-ordinated response from government healthcare workers and quick and effective contact tracing.
  • The Spanish nurse who was the first person to contract Ebola outside of Africa has now recovered from the disease, according to the Spanish government.

Ebola: new vaccine will be 'too late' for current epidemic

17 October 

An Ebola vaccine currently undergoing safety testing will not be ready in time to combat the current outbreak, according to the pharmaceutical company GlaxoSmithKline.

Dr Ripley Ballou, head of GSK's Ebola vaccine research has said that the safety and efficacy of the drug will not be established before the end of 2015. Two other vaccines are also currently in development.

Experts fear that the only way to contain this outbreak is with a safe and effective vaccine as the scale of the epidemic now means that traditional methods of containment will no longer work.

Over 9,000 people are now known to be infected with the virus and more than half have died, according to the latest figures from the World Health Organization (WHO). But the virus is spreading exponentially and the WHO has predicted that there could soon be 10,000 new cases a week.

Professor Peter Piot, the director of the London School of Hygiene and Tropical Medicine who discovered Ebola in 1976, warned that outbreak could last well into next year.

"Then only a vaccine can stop it, but we still have to prove that this vaccine protects, we don't know that for sure," he told the BBC.

In other developments:

  • The WHO has warned that 15 countries, neighbouring or trading with the three countries at the heart of the outbreak, face a real risk of the disease spreading across their borders. These include Ivory Coast, Ghana, Mali and the Central African Republic. "It could lead to major destabilisation of societies and also political destabilisation," Piot told The Guardian.
  • President Barack Obama is facing mounting pressure from Republicans to ban all incoming flights from Liberia, Guinea and Sierra Leone. He says he remains open to issuing travel bans, but only if recommended by public health experts.
  • David Cameron has urged European leaders to implement enhanced screening at airports, introducing measures like those in place at Heathrow airport, which will be extended to Gatwick and Eurostar terminal next week.

Ebola: Obama orders 'Swat team' response to outbreak

16 October

President Barack Obama has outlined enhanced measures to combat an Ebola outbreak in the US, including dispatching rapid response teams to hospitals.

Speaking after heading an emergency meeting in Washington, Obama promised "much more aggressive" monitoring of Ebola cases in the US.

He has also cancelled immediate travel plans in order to oversee the government's response to the Ebola crisis. This comes after a second nurse, Amber Joy Vinson, tested positive for the disease in Texas.

The Centres for Disease Control and Prevention (CDC) has been instructed to send 'Swat-teams' of experts to hospitals that report an infection within 24-hours, USA Today reports. Obama said that hospitals across the country were on stand-by for further cases and that an investigation into how the virus spread in Texas was ongoing.

Obama yesterday took part in a conference call with David Cameron and the leaders of France, Germany and Italy on how to respond to the crisis.

But despite the concerns, Obama continues to downplay the risk of an outbreak in the US, saying the chance of non-healthcare workers contracting the virus is currently "extremely low."

"I am absolutely confident that we can prevent a serious outbreak of the disease here in the United States," he said. "But it becomes more difficult to do so if this epidemic of Ebola rages out of control in West Africa. If it does, it will spread globally."

Over 4,500 people have now died from the outbreak in West Africa.

In other developments:
  • The CDC has come under intense criticism following allegations that Vinson informed them that she had a symptom of the virus, yet was allowed to board a plane and travel across the country. The CDC is now trying to contact all 132 people on board her flight.
  • The UN has warned that the West African region affected by Ebola is facing an impending food crisis as farmers abandon their crops and the movement of goods remains restricted.
  • The campaign group Avaaz says it has identified over 3,000 volunteers, including doctors and other health care workers, who are willing to travel to West Africa to help fight the outbreak.

Ebola remains 'out of control'  with death toll rising to 4,447

15 October

An end to Ebola in Nigeria and Senegal looks near, but elsewhere the outbreak remains "out of control", the World Health Organisation has warned.

New cases in Guinea, Liberia and Sierra Leone "continue to explode in areas that looked like they were coming under control", said the United Nations agency.

The estimated death toll, which multiplies confirmed cases to take into account under-reporting, currently stands at 4,447, reports the BBC.

Bruce Aylward, WHO's assistant director-general, has warned there could be up to 10,000 new cases a week within two months in Guinea, Liberia and Sierra Leone if efforts are not stepped up.

"An unusual characteristic of this epidemic is a persistent cyclical pattern of gradual dips in the number of new cases, followed by sudden flare-ups," the agency said in a statement. "WHO epidemiologists see no signs that the outbreaks in any of these three countries are coming under control."

Yesterday, Barack Obama said that "the world as a whole is not doing enough" to contain the Ebola threat. He will be discussing the crisis in a video conference later today with British, French, German and Italian leaders.

Nevertheless, WHO said it will declare the end of the outbreak in Senegal on Friday and in Nigeria on Monday so long as no new cases arise. In what the agency describes as a "piece of world-class epidemiological detective work", all confirmed cases in Nigeria have been linked back to a Liberian air traveller who introduced the virus into the country on 20 July.

Passengers arriving at Heathrow airport from countries affected by the disease are beginning to be screened by health officials. Passengers have had their temperatures taken and been asked to fill in health forms, which include questions about the traveller's temperature and whether or not they have come into contact with anyone who has died of unknown causes.

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