Ebola: vaccines offer new hope

Gary Finnegan

Gary Finnegan

July 2nd, 2018

Gary Finnegan

‘The last Ebola epidemic killed 11,000 people. The latest outbreak is different. ’

The 2013-2016 Ebola epidemic in West Africa claimed more than 11,000 lives. It took global health organisations almost three years to get the outbreak under control and prompted a major acceleration in Ebola research.

Along with developing better diagnostics and upgrading laboratory facilities, one of the most significant areas of progress was that of vaccination. Several potential Ebola vaccines were in development prior to that West Africa outbreak but progress had slowed.

Not only was demand for the vaccine perceived to be low, regulators had not approved new Ebola vaccines because it was difficult to test in the absence of an outbreak of disease. However, given the urgency of developing a vaccine, researchers, vaccine manufacturers and regulators worked together to ensure they had evidence to show that experimental vaccines were safe and effective.

Now, a fresh outbreak in the Democratic Republic of Congo (DRC) is demonstrating the real-world impact of Ebola vaccination. The outbreak, which was declared an epidemic by the WHO in early May, has killed at least 27 people but is coming under control.

However, the risk has not yet passed, and fears remain that the virus could spread quickly if it reaches Kinshasa, the populous capital of DRC, or crosses into the neighbouring Republic of Congo. Visiting the region, WHO Director General, Tedros Adhanom Ghebreyesus, said the outbreak is not over. “Even if one case…gets to an urban area, that could trigger another epidemic,” he said.

Still, experts from MSF, the Wellcome Trust, the Gates Foundaiton, GAVI and others have echoed the WHO’s view that the availability of an Ebola vaccine has been a game-changer.

‘This is the first time that we’re starting a vaccination campaign in the middle of an Ebola outbreak with an opportunity to stop Ebola – we’re adding a new tool,’ said Dr Michael Ryan, WHO Assistant Director-General, Emergency, Preparedness and Response. “The tools we’ve had in the past have worked but it has been difficult. This is a new tool, gives us new hope to stop Ebola more quickly.”

Ring of protection

Rather than vaccinating everyone in the country, health workers are identifying infected individuals as early as possible and then vaccinating the people around them.

‘It’s called ring vaccination because it’s not a regular mass immunisation campaign where you vaccinate an entire population in a particular geographical area – it’s very targeted,’ Dr Peter Salama, WHO. ‘[We] identify a case and identify all who have had contact with that case, and then the contacts of the contacts – including health professionals. That provides the ring around the case.’

Using the latest in disease surveillance and diagnostics, experts are better equipped than ever to find and trace those who may have been exposed to the Ebola virus.

While it may be too soon to declare victory against Ebola in DRC, the availability of an effective vaccine sees likely to change the course of the latest epidemic. 

Fast facts: What is Ebola?

Ebola virus disease (EVD), formerly known as Ebola haemorrhagic fever, is a severe, often fatal illness in humans. It can be transmitted to people from wild animals and spreads in the human population through human-to-human contact.

Around half of all people infected by Ebola will die from the disease, according to current estimates. The case fatality rates for Ebola infection have varied from 25% to 90% in past outbreaks.

The WHO says supportive care for infected individuals normally focuses on rehydration and treatment of symptoms. However, there is currently no licensed medication to neutralise the virus. A range of blood, immunological and drug therapies are under development.