An apparent slowdown in new cases of Ebola disease in Liberia and Guinea should be taken advantage of. Almost one year after an Ebola epidemic began in West Africa there are at last encouraging signs that it may be receding in some regions. But those responding to the epidemic must not drop their guard — rather, they should seize upon the chance to finish the job.

“Today, we — two dumbfounded doctors — stare at our empty blackboard. We have no more patients.” Last week, that declaration was blogged by a doctor with the humanitarian agency Médecins Sans Frontières (MSF), also known as Doctors Without Borders, at an Ebola treatment centre in the Foya region of Liberia. It is the same story in many parts of the country: empty beds that would have been unthinkable just a few weeks ago when Ebola treatment centres were overflowing. Nationally, the growth in the numbers of those infected in Liberia, the worst-affected country, is no longer exponential but has flattened off.

The epidemic has also stabilized in Guinea. But a resurgence of cases in Sierra Leone is a timely reminder that until Ebola is eliminated throughout West Africa, it remains a major threat. As of 18 November, Ebola has infected at least 15,000 people and killed 5,440 of them in these three main affected countries. But the worst-case scenarios predicted by mathematical modellers, which projected a steady apocalyptic rise in Ebola case numbers, have proved far off the mark (see Nature 515,18; 2014).

Although complacency is as unwise as it is hopefully unlikely — a lull in Ebola cases in the spring prompted authorities to drop their guard, only to see the virus return with a vengeance — there are reasons to believe that the current lull in Liberia and Guinea may continue. And that offers an opportunity to roll back the epidemic at last.

Those responding to the epidemic must not drop their guard.

The exact causes of the lull are unclear. Belated international Ebola control efforts are only now beginning to kick in, and have no doubt contributed. But much of the slowdown is perhaps due to Africans themselves coming to terms with the epidemic and blocking its main routes of transmission. In particular, there has been a reduction in traditional burial practices, which are a key source of spread.

The slowing of new cases in Liberia and Guinea is a welcome reprieve for the health-care workers and scientists who have toiled to control a virus that for months has held the advantage. It is an opportunity to regroup, to consolidate gains, and to go all the more on the offensive.

Until recently, MSF, based in Geneva, Switzerland, was the only serious international presence fighting Ebola on the ground, but logistics meant that it could operate only a few large centralized treatment centres. These large centres, often with hundreds of beds, are still needed to absorb any resurgence, particularly in urban areas. But having only large centres is not ideal. Patients often have to travel for many hours or even days to reach them, and by the time they make it are often beyond recovery. They are also likely to have contaminated others en route, so fuelling the spread of the virus.

With its caseloads falling in recent weeks, MSF is coming out of the trenches and taking the fight to the virus, sending mobile teams and smaller treatment centres to the sites of new outbreaks to try to nip them in the bud. MSF sensibly wants other aid groups to adapt in a similar way. It will be a challenge for the more bureaucratic UN Mission for Ebola Emergency Response, and the US and other national Ebola-treatment efforts, to quickly change their plans, because they are mainly based around large centres. But it is crucial that the response to Ebola is flexible in the face of the shifting epidemiology.

The slowdown is also buying precious time for the testing of drugs and vaccines: clinical trials of vaccines in particular are being fast-tracked, with the first results due at the end of 2014. Unfortunately, however, drugs and vaccines have captured the spotlight and resources, while more mundane interventions that could have an immediate impact have been neglected. Better rehydration and electrolyte control can dramatically reduce mortality: the case fatality rate for patients treated in rich countries has been a fraction of the 70% seen in West Africa. Testing convalescent blood and serum from survivors — a potentially game-changing treatment — should also be a priority.

At the start of October, the United Nations and the World Health Organization set quantitative targets for safe burials, contact tracing and other key public-health control measures, which the international community was to meet by 1 December. It is already obvious that most of these targets will not be met. The breathing space offered by the current lull in Liberia and Guinea offers an opportunity to fill gaps and ramp up coverage of countermeasures. It must not be wasted.