Ebola: vaccine is no silver bullet

2014-11-02 06:00

An Ebola vaccine has been in the works for nearly a decade – but work on it stalled because there was no real urgency, virologists say.

Until earlier this year when the disease hit west Africa and sparked a pandemic, confirmed Ebola cases had been

clustered in remote villages in the Democratic Republic of Congo (DRC).

Robin Shattock, professor of Mucosal Infection and Immunity at London’s Imperial College, said the DRC had managed to contain the disease during previous outbreaks.

Shattock was in Cape Town this week for the HIV Research for Prevention conference, at which vaccines were a major talking point.

Mary Marovich, director of the Vaccine Research Programme at the National Institute of Allergy and Infectious Diseases in the US, said the National Institutes of Health had been working on a vaccine for “almost10 years”.

“The vaccine has been shown to protect monkeys from the Ebola virus up to five days after infection. However, due to the fact that there was no outbreak, researchers spent most of the time testing the vaccine on animals,” Marovich explained.

Two promising candidate vaccines – cAd3-ZEBOV developed by GlaxoSmithKline in collaboration with the US National Institute of Allergy and Infectious Diseases and rVSV-ZEBOV, developed by the Public Health Agency of Canada – are being tested for safety and their capacity to induce an immune response in humans.

Studies are being conducted in Mali, the UK and the US. This week, the World Health Organisation (WHO) announced that Switzerland had approved a safety trial on cAd3-ZEBOV.

About 120 people are expected to be enrolled in Switzerland and the first results are expected next month. Vaccines must be tested for safety before their efficacy is examined in clinical trials.

Marie-Paule Kieny, assistant director-general for Health Systems and Innovation at the WHO, said that if cAd3-ZEBOV or rVSV-ZEBOV are shown to be safe and effective, “either of the vaccines could be scaled up for production during the first quarter of next year, with millions of doses produced for wide distribution in high-risk countries”.

But a vaccine is not a magic bullet, scientists warn.

In an interview with the website Ebola Deeply this week, infectious diseases specialist Dr Jesse Goodman said: “We just don’t know how long it’s going to take for them to be declared safe, or even if they’ll be effective.

“People are working very quickly to get initial human studies done, and also to scale up potential manufacturing for the leading candidates. But it’s a complex business and none of these vaccines has so far been manufactured in large amounts. Even by next [northern hemisphere] spring is pretty optimistic; things usually take longer than people project,” Goodman told the website.

“A vaccine could be a really important tool, but if we don’t have solid studies that show that it works and is safe, I think it would be really problematic just to immunise huge numbers of people with a vaccine we don’t understand.”

Virologists told City Press that there was more to beating Ebola that just producing a vaccine.

“Ebola is preventable and if managed correctly, it can be contained,” Shattock said.

“Congo, for instance, has been reporting cases for decades, but it managed to contain it to certain parts of the country by following simple prevention and treatment strategies.”

Marovich said that more resources “like protective gear, medical consumables, personnel and funds” in affected countries “can go a long way”.

Join the conversation!

24.com encourages commentary submitted via MyNews24. Contributions of 200 words or more will be considered for publication.

We reserve editorial discretion to decide what will be published.
Read our comments policy for guidelines on contributions.

24.com publishes all comments posted on articles provided that they adhere to our Comments Policy. Should you wish to report a comment for editorial review, please do so by clicking the 'Report Comment' button to the right of each comment.

Comment on this story
Comments have been closed for this article.

Inside News24

Traffic Alerts
There are new stories on the homepage. Click here to see them.


Create Profile

Creating your profile will enable you to submit photos and stories to get published on News24.

Please provide a username for your profile page:

This username must be unique, cannot be edited and will be used in the URL to your profile page across the entire 24.com network.


Location Settings

News24 allows you to edit the display of certain components based on a location. If you wish to personalise the page based on your preferences, please select a location for each component and click "Submit" in order for the changes to take affect.

Facebook Sign-In

Hi News addict,

Join the News24 Community to be involved in breaking the news.

Log in with Facebook to comment and personalise news, weather and listings.