Vaccine research: which diseases are top priority?

Editorial Board

Editorial Board

September 25th, 2015

Editorial Board

‘Medical research is expensive and risky. Which diseases should be prioritised – and what can be done where there is no ‘market’ for vaccines against rare diseases?’

Dr Seth Berkley knows a thing or two about infectious diseases. As a medical epidemiologist, founder of the International AIDS Vaccine Initiative, and CEO of the GAVI vaccine alliance, he is on the frontline of expanding access to immunisation across the world.

Berkley’s recent TED talk draws on this experience and, in light of the global response to the Ebola outbreaks in West Africa, explores how society prioritises investment in vaccine research.

The talk begins thus:

The child’s symptoms begin with mild fever, headache, muscle pains, followed by vomiting and diarrhoea, then bleeding from the mouth, nose and gums. Death follows in the form of organ failure from low blood pressure.

But Berkley is not talking about Ebola – he’s describing an extreme case of dengue fever, another disease against which there is currently no vaccine (although there are a number of them on the way).

His point is that dengue fever kills 22,000 people per year which is twice the number killed by Ebola in the almost 40 years since it was first described. Measles too is much more infectious and prevalent than Ebola.

The question is: why is Ebola grabbing all the headlines?

The short answer is fear. Fear of a horrible death; fear that there is neither a therapy nor a vaccine.

But, he says, it made international headlines only when it became a perceived threat to people in wealthy countries. After that, years of slow progress on Ebola vaccines was rapidly accelerated.

Berkley also notes that those at highest risk of many infectious diseases are least able to pay for vaccines – especially newer ones which have cost millions to develop.

Is this a controversial point? Hardly. The GAVI chief is merely highlighting a feature of market economics which, without intervention, would leave the world’s poorest people without vaccines. It would also skew how we prioritise vaccine research.

The point of Berkley’s talk is that such ‘market failures’ highlight the need for incentives or subsidies to ensure researchers address medical need.

He also calls for greater effort to pre-empt and prevent infectious disease outbreaks. Vaccines take time and money to develop. Rather than wait until a disease such as Ebola or dengue is threatening large numbers of people, the global health community should be identifying threats as early as possible.

We spend virtually nothing to prevent something as tangible and evolutionarily certain as epidemic infectious diseases. And make no mistake about it — it’s not a question of “if,” but “when.” These bugs are going to continue to evolve and they’re going to threaten the world. And vaccines are our best defence.

Other hurdles

Berkley makes some great points in his short talk but there are even more obstacles to boosting vaccine access. Sometimes the barriers can be technical.

For example, vast sums of public and private funding have been invested in HIV research yet a vaccine remains elusive. The medical need is there – in countries rich and poor – so the commercial imperative is not a problem.

TB has also proven to be a challenge for vaccine researchers despite clear demand for a better vaccine than the BCG.

For rarer diseases with unpredictable epidemiology, the size of the market can be a problem – but it’s not the only one. Even vaccine candidates that make through the early phases of clinical testing can stall because demonstrating efficacy in large trials are logistically difficult.

Are there technical or perhaps even regulatory changes that could help prepare for the next infectious disease crisis?

Tell us what you think?

Which diseases should be the top targets for vaccine researchers?

Want to know more about how vaccines are developed? Watch this short video.