Since 2010, Harvey Rubin, director of strategic threat analysis and response at the University of Pennsylvania in the US, has worked on a plan to use surplus energy from off-grid mobile phone towers to power pharmaceutical cold chains in isolated parts of the world.

He established Energise the Chain (EtC) to forge public-private initiatives with governments, global health organisations such as the World Health Organization and UNICEF, and mobile operators in order to keep vaccines at stable temperatures until they can be used, a challenge those running clinical trials will be all too familiar with. Just probably not quite like this.

EtC’s first mobile operator partner was Econet Wireless in Zimbabwe, Africa, which has been kitting out cell sites in remote parts of the country with sensor-equipped refrigerators.

The tragedy of the earthquake in Haiti inspired Rubin to up his efforts in tackling threats to supply integrity in developing nations. He points out that vaccines must be stored at a temperature between 2 and 8°C, or else they will degrade in terms of their activity and will lose further activity when freezing or thawing.

Deterioration occurs at 8°C and above if vaccines are kept in these conditions for a prolonged period. When sera freeze, microcrystals develop, breaking the bonds of the biological molecules in lipids and proteins. Heat generates too much energy, which also breaks bonds. With such poor tolerance to temperature changes, shipments cannot be left on pallets at the airport. Even if they endure the transfer to a lorry and central storage, each successive segment − on the back of a bicycle or donkey, or the backpack of a healthcare worker who must venture miles to a clinic − puts them at further risk.

The overall impact of vaccinating children properly is a multibillion-dollar concern, and brings a huge social and economic benefit.

So the pressing issue is how to keep vaccines cold. As Rubin says, vaccine-preventable death is an enormous problem. Around 2.5 million children under the age of five die of vaccine-preventable diseases every year; measles alone claims the lives of up to 800,000 children.

Polio, rotavirus and other diarrhoeal diseases, tetanus, whooping cough, pneumococcal disease, pertussis – all these diseases can be prevented with vaccines. However, if the product isn’t stored at the right temperature, then a child will receive a vaccine believing they are protected when they are not.

The importance of keeping vaccines cold is absolutely paramount. Rubin emphasises that vaccines are not simply about protecting the child from pneumococcal disease or measles, but that the child also then achieves more at school, joining the workforce and becoming productive members of society.

"The overall impact of vaccinating children properly is a multibillion-dollar concern, and brings a huge social and economic benefit," Rubin says.

Mobile power

Rubin’s campaign was partly inspired by his close friend, David Morse, who had related fellow actor Sean Penn’s struggle to immunise youngsters in Port-au-Prince, Haiti. Rubin recalls a conversation from years earlier with a cloud-computing expert: "He said there were more cellphones than toilets in the world… If you have cellphones, there must be energy nearby, every mile or two. Signals are continuously transferred, tower to tower. Their power is everywhere."

A breakthrough came in May 2010. On stage in Franklin Field for the University of Pennsylvania’s 254th commencement, Rubin met Paul Farmer, a founder of Partners in Health, which brings high-quality healthcare to poor nations. Also in attendance was David L Cohen, chairman of Sean Penn’s board of trustees.

Mobile phone towers require dependable sources of power. Hence, in developing nations, where electricity is troublesome and blackouts can drag on for several days, telecoms companies supply their own using diesel generators. Operators have a financial incentive to maintain and protect them. They are always anticipating growth so they will commonly produce more energy than they need. Additionally, ministries of health already face huge outlays of around $1 million each year to power their refrigerators using diesel; that’s around 12% of the typical annual health budget.

An expensive alternative source of energy would remove a huge burden. It made sense that some of the excess power could be harnessed to run refrigerators for vaccines, but Rubin wasn’t yet sure if it was practical. His colleague, Ali Jadbabaie, an electrical engineer and applied mathematician, called an ex-classmate in Iran whose company installs mobile phone towers in remote villages and confirmed that towers have electrical outlets for testing equipment. Plugging in a refrigerator should be possible.

Jadbabaie later confirmed this with more in-depth research, but the real turning point for Rubin came with the realisation that this was now a private sector initiative.

"The private sector, the cell tower operators, have an enormous incentive to keep the energy on," he explains. "They spend a lot of money on energy, so if they could charge even a small amount to supply energy for the vaccines, they would make a little bit of money. Ministries of health would save a lot of money and, of course, the children win; everybody wins."

Rubin called on a friend at Wharton School of the University of Pennsylvania, for help in developing a business model. Within a year, children in ten villages in Zimbabwe were vaccinated. Around 200 working sites were up and running at the close of last year, with further plans to expand into Lesotho, Burundi and India.

More than 250,000 children have been vaccinated so far, according to Precious Lunga, head of health at Econet Wireless. Not only are base stations powering refrigerators, but Econet is also using remote sensors to track how long the doors remain open and by how many degrees the temperature rises when vaccines are taken out.

The project has also encountered stumbling blocks, however. Many of the towers are constructed on high ground to maximise reception and security, which means it can be difficult for healthcare workers to manage the often arduous uphill journey to reach the refrigerator. Rubin also believes it will take several more years to serve the most remote areas. For those towns closer to the grid and many that cannot yet access the towers, Econet has become a focal point, providing refrigerators that stay cold for an impressive ten days without power.

Some unusual technological challenges remain. Rubin raises the point of how to keep track of the children through infant biometrics. He is also interested in how to assure privacy, and how to enable a real-time inventory to ensure the right vaccines are in stock at the right time. Rubin says he is very happy with Econet but also keen to find more partners.

"Harnessing the capabilities of the mobile phone industry and their outreach in remote regions – it seems like it can be a really viable and sustainable solution if we can get more mobile phone and tower operators involved," he says.

Data act

How to make best use of the data collected from the temperature sensors in Zimbabwe is a responsibility that Rubin takes very seriously.

"The data is so important," he says. "Informed management of the entire supply chain depends on it. It goes all the way back to manufacturers to inform them of how many doses they need to produce. As new vaccines arrive on board, we have to be sure that the volume is achievable. We need to know we have enough room to store them. With new vaccines, we need more space in refrigerators. Without the data, we’re stuck. It’s a big issue."

EtC is not the only organisation focused on cold chain issues in the developing world. PATH is an international non-profit organisation that aims to accelerate innovation to improve global health, especially among women and children. PATH works mainly in Africa and Asia to tackle the toughest healthcare challenges. This means working closely with partners to promote, among other technologies, a vaccine vial monitor that indicates if a vaccine has been exposed to too much heat, and solar-powered refrigerators.

Harnessing the capabilities of the mobile phone industry and their outreach in remote regions – it seems like it can be a really viable and sustainable solution.

Rubin warns, though, that more effective regulation is needed to support the technology. His 2011 report for the Organisation for Economic Co-operation and Development entitled ‘Future Global Shocks: Pandemics’ emphasises the desirability of international harmonisation of regulations and financially sustainable basic research, especially in tackling pandemics.

He has also suggested that a health impact fund (HIF), first proposed in 2008, should be used as a tool to incentivise development and production of drugs and vaccines for the poor. The HIF would be financed by a percentage of gross domestic profit from contributing nations.

Under this plan, development projects would be allocated HIF funds based on the contribution the product would make to global health. Products created using HIF funds would be distributed wherever needed for the lowest production cost.

He says the HIF would enable the ramping up of production and distribution of lower-priced drugs and vaccines − and discourage the proliferation of counterfeit medicines.

When it comes to pandemics, Rubin criticises failures in production preparedness and blames a lack of globally shared real-time information.