Science has so far taken a back seat as the Ebola outbreak has continued to spread. Research has deferred to the need to gear up the public-health response. But there is a growing sense that, unless science can somehow now change the game, the outbreak will be difficult to bring under control.

The Ebola virus has killed more than 4,800 people in six countries, and has affected people in another two, the latest being Mali. There are still not enough medical staff and treatment beds to handle the current caseload. The World Health Organization (WHO) projects that as many as 10,000 new cases could be arising per week by December if the outbreak is not turned around.

Enter science. Speeding the development of treatments and vaccines is one area in which the international community is trying to move forward. On 22 October, the US Biomedical Advanced Research and Development Authority and the US Army awarded US$17.1 million to Profectus BioSciences, a company based in Baltimore, Maryland, that is developing vaccines against Ebola based on vesicular stomatitis virus. It is the third candidate Ebola vaccine to have moved towards or into clinical trials this year. On 24 October, the WHO outlined plans to test the first two — one licensed to NewLink Genetics of Ames, Iowa, the other being developed by GlaxoSmithKline, headquartered in London. These two vaccines have already entered human safety trials and the WHO says that they could be tested in health-care workers and others in West Africa as early as December.

In the meantime, aid agencies such as Médecins Sans Frontières (also known as Doctors Without Borders) and researchers funded by the European Union will test candidate Ebola treatments, including experimental drugs, medicines already approved for other uses that could be made available ‘off label’, and purified plasma or blood from Ebola survivors.

Beyond treatments and vaccines, scientists have more fundamental questions, about both the Ebola virus behind the current outbreak and other viruses in the family to which it belongs, the filoviruses. This group includes Marburg virus, also capable of causing a lethal haemorrhagic fever, which killed a Ugandan health-care worker on 28 September. A third filovirus outbreak occurred this year in the Democratic Republic of the Congo, where an Ebola outbreak unrelated to that in West Africa has killed 49 people.

Whether it is Ebola virus or something completely different, there will be a next time.

The emergence of three filovirus outbreaks this year and the increasing frequency and reach of such outbreaks — which have occurred every year except 2 in the past 21 years — should serve as the clearest warning possible: we urgently need to understand more about the pathology, distribution, epidemiology and clinical aspects of these viruses. A World View on page 537 argues that such science should help to steer the response; a News Feature on page 554 lays out the five most pressing questions about the filo­viruses, and says why answering them might help to prevent a future outbreak or even help to bring this one under control.

For instance, new filoviruses have been discovered within the past five years, such as the Lloviu virus discovered in 2011 in bats in Spain. And scientists have learnt that these viruses have a much more widespread distribution than was suspected. The Reston virus, for example, an ebolavirus that does not seem to harm humans, has turned up in recent years in pigs in both the Philippines and China. Scientists suspect that there are more of these viruses to be found, in more places, and urgently want to understand why some are lethal to humans and others are not — and whether that could change.

It is also not known which animals harbour Ebola virus in the wild, or how the first person infected in the West African outbreak last December contracted the disease. Understanding this is crucial if people are to avoid a possible reservoir in the future.

It has been difficult to answer these questions for many reasons, such as the (fortunate) relative rarity and un­predictability of human filovirus outbreaks. And laboratory studies require highly contained, specialized biosafety-level-4 (BSL-4) labs — of which there are too few around the world.

Thanks to a biodefence building boom over the past decade, there are now 13 such labs planned or operating in the United States. Canada, France, Australia, Germany, the United Kingdom, South Africa, Gabon and Russia are among the select nations that also have such facilities. But there are major research-funding nations, such as Japan, that do not have BSL-4 labs, or do not allow them to perform the highest-containment research because of worries that pathogens could escape and spark lethal local epidemics.

The current Ebola outbreak proves the fallacy of that decision. The world would not be in the position it is today, with the possibility of deploying an Ebola vaccine during the current outbreak, without the existence of both high-containment facilities and money for research on diseases that are, thankfully, rare in developing countries. More of both, in more places, can only hasten our understanding of Ebola and other diseases. Because one thing is clear: whether it is Ebola virus, another filovirus or something completely different, there will be a next time.