Yemen is the latest victim of a cholera pandemic that began in 1961, one that could wreak havoc widely for decades to come, says Seth Berkley , CEO of Gavi, the vaccine alliance

Clean drinking water can prevent cholera’s spread Yahya Arhab/EPA/REX/Shutterstock

For six decades, a deadly pandemic has raged, killing millions of people and infecting tens of millions more. Yet because it has been eliminated from wealthy countries barely anyone in the West is aware that it is still ongoing.

Beginning in Indonesia in 1961, the current cholera pandemic – the seventh in modern history – has persisted for six decades. It has its own strain of the bacteria that causes the disease – called El Tor – which has spread to more than 150 countries, sometimes smouldering, sometimes blazing, but never fully extinguished. Almost all of those affected today are the poor and vulnerable in disaster zones or fragile states – think of the outbreak in Haiti in 2010.

The latest flare-up is in Yemen, where at least 1500 people have died and more than 185,000 have been infected amidst war and famine. Sadly, even with a million doses of cholera vaccine on their way to Yemen, things are likely to get worse before they get better.


For the pandemic as a whole, the prospects are also dire.

This is all the more tragic because the disease is as preventable as it is contagious. The World Health Organization (WHO) estimates that with the right strategy and funding, cholera could be eliminated from most of the world within a few years, to the point that it would no longer pose a global health threat.

Cholera hotspots

Outbreaks can be avoided by improving access to clean water, sanitation and hygiene in cholera hotspots, as well as vaccinating those at risk.

The challenge is that often these hotspots face protracted crises that limit the ability to make improvements, for example in Somalia and South Sudan. In such cases immunisation has an even bigger role, provided it can be done early enough.

The good news is that we have safe, effective and affordable vaccines. Before 2011 that wasn’t the case. The only vaccine that met WHO safety and efficacy standards wasn’t suited to developing countries because it needed to be administered using clean water.

But now with support from Gavi, the vaccine alliance I head, this year will see the production of 17 million doses of a vaccine that doesn’t rely on clean water. This will also be used to maintain a global stockpile of 2 million doses for emergency use.

However, in practice, it is hard to get vaccines into crisis zones quickly enough to prevent an epidemic developing. Instead, vaccine use becomes more about control and containment.

Limited sanitation

Epidemics will become more likely, particularly in Africa, where the population is expected to double by 2050 and quadruple by 2100. This, combined with additional pressures from climate change, such as land degradation, rising seas, drought and famine, not to mention conflict, could see tens of millions of people displaced. Inevitably, more will be driven towards cities. In 1950, two-thirds of the world’s population lived in rural areas, and just a third in urban areas. By 2050, this ratio is forecast to be reversed.

More people living in less space, placing more strain on already limited sanitation and drinking water systems, will provide a fertile breeding ground for cholera. At the same time, the sheer scale of modern megacities has the potential to outstrip vaccine supplies, limiting the ability to prevent or respond to outbreaks in this way.

It doesn’t have to be like this. Yemen reinforces a crucial lesson: when it comes to cholera we need to be proactive, not reactive.

When we know there is a very high chance that the disease will appear, we need to vaccinate as soon as possible. To do so, we will need to better understand how the infection initially spreads and which vaccination strategies would be best to prevent this.

In conflict-prone areas this is even more critical, because brief periods of peace may be few and far between. And wherever it is feasible we need to improve access to clean water, hygiene and sanitation. Ultimately, if we don’t want this pandemic to last another six decades then we need to acknowledge it and treat it as a growing threat.