A healthy body has three essential systems for staying that way. There is physical fitness, building resilience against threats. There is the brain, to spot danger and take action. And there is the immune system, to neutralise infections that breach other defences.

The world needs similar systems to protect against epidemic and pandemic diseases. We need a fit body – a basic infrastructure of public health. We need a nerve centre for preparedness and response – an international organisation to tackle threats. And we need an immune system – vaccines and drugs to prevent and treat disease.

Today, all three global systems have such significant weaknesses that they are incapable of delivering an effective response as a whole. Ebola demonstrated that too many countries lacked the health infrastructure to identify new infections and contain them at source. It exposed the need for a stronger World Health Organisation (WHO) to lead preparedness and response. And it showed up a pharmaceutical development pipeline in which promising vaccines had been parked for want of incentives to progress them. The same issues were apparent for Sars, Mers and influenza. The Zika emergency is returning them to the spotlight.

Ebola was a preventable tragedy. Its lessons are now abundantly clear. A report this week from a UN high-level panel completes a cycle of four comprehensive inquiries. Its conclusions align with those reached by experts convened by the WHO, US National Academy of Medicine and the London School of Hygiene and Tropical Medicine. There is an agreed road we must take.

First must come a fitter body. Just as robust health protects individuals, robust health systems protect everyone. When Ebola spread to rich countries, it was rapidly contained. It was in three countries with very poor health infrastructure that the disease took devastating hold.

Guinea, Sierra Leone and Liberia are not the only countries that lack essential capacity. Only a third of governments even claim to have implemented the basic requirements of the 2005 International Health Regulations. There is no process for monitoring compliance and no accountability. Neither is much aid available for countries that cannot afford basic systems. States that detect outbreaks often delay reporting, as economic consequences are severe and incentives and compensation absent.

This cannot be resolved at national level. Governments of every country must recognise that investing in public health protects their citizens. Richer nations must recognise that helping others to achieve basic standards is not altruism but a self-interested cost of security. As the spread of Sars to Canada showed, pathogens do not care for borders. Pandemic defences are as strong as their weakest links. There must be incentives for declaring outbreaks, and more available aid.

Next we need a sharper brain. Better infrastructure cannot prevent every emergency, and an international agency with legitimacy is needed to plan and execute swift, effective responses. There is no viable candidate besides the WHO, but it lacks the capacity or culture required. Margaret Chan, its director general, has to her credit acknowledged this and established an emergency response programme and a $100m contingency fund.

This is progress, but will take us only so far. The budget is insufficient and must be replenished when spent: a UN panel recommends tripling resources to $300m and raising national WHO subscriptions by 10% to make funding sustainable. The response unit needs a powerful director backed by an independent board who can cut through WHO’s regional and national bureaucracies. Chan is about to begin her final year as director general. Establishing this capacity would be a fine legacy.

Facebook Twitter Pinterest A health worker carrying out fumigation as part of preventive measures against the Zika virus and other mosquito-borne diseases at a cemetery on the outskirts of Lima. Photograph: Mariana Bazo/Reuters

The final requirement is a better immune system. That means a transformed approach to research and development of vaccines and drugs.

All four reports agree on the need for public, private and philanthropic sectors to step up investment in R&D for diseases where industry lacks much prospect of a market return. When such research takes place at all, it generally relies on the goodwill of pharmaceutical companies prepared to take a loss – Ebola vaccines are a prime example. That isn’t sustainable, not when we know of dozens of threatening pathogens for which, like Ebola in 2014 and Zika today, we have no vaccine or cure.

As traditional vaccine and drug development timelines are too slow for emergency response, we must invest in technologies that enable more rapid deployment. Zika, a mosquito-borne disease, has demonstrated the need for transformative control of the way diseases are transmitted. Debates over the risks and benefits here need to be evidence-based. These technologies will be useful beyond pandemic outbreaks, for diseases such as malaria which kill and disable every day.

The WHO is drawing up a blueprint for priority research, which can give legitimacy to independent financing and development partnerships. Issues of trial design and regulatory approval must also be worked through in advance, so testing is not delayed when epidemics begin. Vaccines were eventually tested in the Ebola epidemic, but only after months of wrangling. We must not be so slow again.

The strong consensus forged by the four inquiries is not really new. Similar recommendations emerged from reports into Sars and H1N1 flu. The Ebola inquiries must be the last to make them. We have reached a point of decision. With Ebola fresh in the mind, and Zika very current, world leaders must seize on will and momentum that may not exist again, and deliver this manifesto for health security.

Dr Trevor Mundel is president of the global health division at the Bill & Melinda Gates Foundation