ews of the latest Ebola outbreak in the Democratic Republic of the Congo is an urgent reminder that we need to change the way we fight disease, and we need to do so now.
Over the last few decades, the number of disease outbreaks has more than tripled, culminating in three major epidemics in recent years — Ebola, yellow fever, and Zika. Despite this, governments often respond to outbreaks only once they occur, rather than investing in ways to stop them in the first place. If this continues, there will be a growing risk that we will not only undermine the great progress that has been made in fighting infectious disease, but we could even see a resurgence of highly preventable diseases that were previously in decline.
Global trends are steadily altering the global health landscape, making it easier for disease to spread. Despite the scientific and medical advances of the last century, climate change, population growth, human migration, urbanization, vaccine hesitancy, and antimicrobial resistance could start to make future outbreaks increasingly difficult to contain.
One example of this is cholera: a highly neglected disease that is entirely preventable through access to clean water and good sanitation and hygiene. It has almost come to be expected in areas of extreme poverty, such as in Cox’s Bazar in Bangladesh, where nearly more than 900,000 Rohingya refugees have settled, or in war-torn countries like Yemen.
While fragile states are particularly vulnerable to diseases like cholera, it can sometimes be a consequence of economic growth. Zambia, one of the fastest-growing economies in the world, has experienced a cholera outbreak every year for the last 35 years, mainly due to large areas of unplanned urbanization in parts of its capital, Lusaka.
This is part of a growing global trend of urbanization that is expected to lead to two-thirds of the world’s population living in urban areas by 2050. Whether people are drawn from rural areas to cities by better economic prospects, or driven by conflict or climate-related events, such as flooding, desertification, or land degradation, the result is often the same — slums.
Large numbers of often unvaccinated people living close to each other in squalid conditions, with limited access to primary health care facilities or clean water and sanitation, create a fertile breeding ground for infectious disease and the insects that spread them. One example is the recent outbreak of antibiotic-resistant typhoid spreading in the slums of Karachi, Pakistan. One case has already been exported to the United Kingdom.
Disease tends to spread more easily and more rapidly among denser populations. And as populations grow, they can put a greater strain on already stretched resources, from sanitation to medical resources such as vaccines. Over the last few years, we have seen demand for emergency stockpiles of vaccines for diseases like cholera and yellow fever increase dramatically. While we can currently meet this demand, the growing number of mega-cities with populations of 10 million or more, and the increasing risk of urban epidemics that come with them, could deplete these stockpiles very quickly.
With diseases like Ebola, where there is no cure and predicting outbreaks is difficult, vaccination is essential. And since the West African epidemic, which killed more than 11,000 people and infected nearly 29,000, we now have an investigational vaccine from Merck that a trial at the tail end of that outbreak showed to be safe and effective.
With $1 million of initial operational support from Gavi, the Vaccine Alliance, which I lead, up to 300,000 available doses from Merck can be used by the World Health Organization and its partners to try to swiftly contain and end the DRC outbreak. For the people of Bikoro, in the DRC’s Equateur province, where there are already 55 suspected cases of Ebola and 28 deaths, this vaccine could be a lifesaver. Without such tools, we risk further spread, which could be devastating, particularly as we have now seen cases in the urban center of Mbandaka, the provincial capital of Equateur.
While stockpiles are essential, they remain only part of the solution. As cities continue to grow, our best defense will be anticipating outbreaks before they occur. For some diseases, that means making childhood immunization and pre-emptive vaccination campaigns a priority. In other cases, it may mean greater investment in sanitation infrastructure, which can help prevent not just cholera but other water-borne diseases, like the diarrhea-causing rotavirus. And many poor countries are in desperate need of basic diagnostics and surveillance capabilities, enabling them to detect an outbreak as early as possible gives them an opportunity to quickly respond.
All too often with infectious diseases, it is only when people start to die that necessary action is taken. To avoid this, the answer is simple: All countries must step up their long-term efforts to prevent and, wherever possible, eliminate infectious disease. If we keep waiting until outbreaks occur, we may soon find that our ability to respond, contain, and end them is gravely inadequate.
Seth Berkley, M.D., is CEO of Gavi, the Vaccine Alliance.