Vaccine gives monkeys Ebola immunity

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Vaccinated monkeys have developed “long-term” immunity to the Ebola virus, raising a prospect of successful human trials. Experiments by the US National Institute of Health showed immunity could last at least 10 months.

Now, human trials of the vaccine have begun in the US with the first patient a 39-year-old woman, and will be extended to the University of Oxford in the UK as well as in Mali and Gambia. Animal research, on which the decision to begin human trials was based, was published in the journal Nature Medicine. It shows four crab-eating macaques all survived what would have been a fatal dose of Ebola virus five weeks later. However, only half survived an infection 10 months after immunization, but Dr Anthony Fauci, the director of the US National Institute of Allergy and Infectious Diseases, believes a booster shot could make the vaccine really durable. People will be given just the initial jab, not a follow-up booster, in the trials.

The World Health Organisation (WHO) said safety data would be ready by November 2014 and, if the vaccine proved safe, it would be used in West Africa immediately with healthcare workers and other frontline staff being prioritised for vaccination.

There will also be separate trials of the vaccine against just the Zaire Ebola species.

At present several experimental treatments are being considered to help contain the spread of Ebola including a vaccine being developed by the US National Institute of Allergy and Infectious Diseases and pharmaceutical giant GlaxoSmithKline. It uses a genetically modified chimp virus containing components of two species of Ebola – Zaire, which is currently circulating in West Africa, and the common Sudan species.

The viral vaccine does not replicate inside the body, but it is hoped the immune system will react to the Ebola component of the vaccine and develop immunity.

Existing supplies of all experimental medicines are limited and will not be sufficient for months to come, while the outlook for vaccine supplies looks “slightly better”, the WHO said in a statement on September 5th after two days of talks in Geneva attended by nearly 200 experts.

The UN agency said blood-derived products and serum from survivors may be used to treat Ebola virus immediately and two vaccines could be available for health workers by the end of 2014. According to the WHO, 256 health workers have been infected and 134 have died in this outbreak.

However, good clinical care, rigorous infection prevention and control measures, and the tracing of people who have been exposed remain crucial for ending the epidemic, which has killed at least 2,097 in West Africa since March.

ZMapp, made by California-based Mapp Biopharmaceutical Inc., has been given to seven people infected with Ebola, including two American aid workers and a Briton who all recovered, but it remains unproven and supplies have run out. The US government has pledged up to $42.3m to accelerate its testing. Mapp Biopharmaceutical president Dr. Larry

Zeitlin said was vital to conducting early-stage safety studies of the drug as the jury is still out on both its safety and efficacy.

“The U.S. support will enable us to figure out what the appropriate dose is and scale up manufacturing. With a drug you have not only to make it, but make it consistently to the same quality. The award given us is for 18 months. We will probably be in human trials beginning in 2015,” Zeitlin said in an interview on the sidelines of the WHO meeting.

More than six months into the crisis, the disease is spreading faster than ever and organisations across the world are directing cash and supplies to the region. The UN has said $600m will be needed to fight the outbreak and an Ebola crisis centre would be set up to coordinate the response. The European Union (EU) on September 5th pledged $180m (€140m) to boost the fight against Ebola in West Africa. The funding will be used to strengthen health systems, train health workers and pay for mobile testing laboratories.

Over €97m will be spent on budget support to Liberia and Sierra Leone in order to help them deliver public services, including health care, and maintain macroeconomic stability, the European Commission said in a statement.

A ‘Market Failure’

Meanwhile the scientist leading Britain’s response to the Ebola pandemic, Professor Adrian Hill of Oxford University, has launched a devastating attack on “Big Pharma”, accusing drugs giants of failing to manufacture a vaccine, not because it was impossible, but because there was “no business case”.

According to Professor Hill, the outbreak could have been “nipped in the bud”, if a vaccine had been developed and stockpiled sooner – a feat that would likely have been “technically more doable” than making one for other challenging and more widespread diseases such as TB, HIV and malaria, which receive more funding..

Professor Hill maintains that the fact that a vaccine had not been available to stop the disease when it emerged in Guinea six months ago represented a “market failure” of the commercial system of vaccine production which is dominated by the pharmaceutical giants.

Professor Hill explained that the GSK/NIH vaccine, which is based on a strain of chimpanzee cold virus and known as ChAd3, was originally developed in the US for potential use against a bio-terror attack – and only existed because of high levels of funding allocated to vaccines designated for defence.

Asked why a fully tested and licensed vaccine had not been developed, Professor Hill said: “Well, who makes vaccines? Today, commercial vaccine supply is monopolised by four or five mega- companies – GSK, Sanofi, Merck, Pfizer – some of the biggest companies in the world.

“The problem with that is, even if you’ve got a way of making a vaccine, unless there’s a big market, it’s not worth the while of a mega-company …. There was no business case to make an Ebola vaccine for the people who needed it most: first because of the nature of the outbreak; second, the number of people likely to be affected was, until now, thought to be very small; and third, the fact that the people affected are in some of the poorest countries in the world and can’t afford to pay for a new vaccine. It’s a market failure.”

In the wake of the outbreak, governments should now work with the pharmaceutical industry to push through development of vaccines against “outbreak diseases” such as Ebola, as well as Sars, Marburg and Chikungunya, Professor Hill said, with the goal of establishing stockpiles in vulnerable countries.

Lockdown for Ebola

Sierra Leone has announced a four-day nationwide lockdown in a desperate attempt to halt the continuing spread of Ebola. In a move to slow infection rates and allow health workers to isolate fresh cases of the disease, people will not be allowed to leave their homes from September 18th to 21st. More than 21,000 people will be recruited to maintain the lockdown.

Médecins sans Frontières (MSF) said the measure risked driving victims “underground”, and potentially spreading the disease further. The fight against it has already been hindered by misinformation, and mistrust of health workers.

Ebola casualties

Up to September 5th: 2,105

Ebola deaths – probable, confirmed and suspected

* 1,089 Liberia

* 517 Guinea

* 491 Sierra Leone

* 8 Nigeria

(Source: WHO)

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