The ColdTrace 5 device. Photo: Nexleaf Analytics

Vaccines are credited with saving millions of lives each year, but one in five children still do not receive the basic immunizations needed to stay healthy. Seventy percent of unvaccinated children are concentrated within 10 developing countries that have large populations and weak immunization systems, according to the Bill & Melinda Gates Foundation.

With the theme of “providing peace of mind” to healthcare workers across the globe, nonprofit Nexleaf Analytics is on a mission to develop innovative products that safeguard vaccines and other medical supplies in challenging environments.

Nexleaf is fulfilling this mission through the development of ColdTrace—a wireless remote temperature monitoring (RTM) system that was specifically designed for vaccine refrigerators operating in rural health clinics in developing countries.

ColdTrace has already been implemented in more than 7,000 health facilities around the globe, but a new partnership with and Gavi, the Vaccine Alliance, will expand the reach of the technology even further. will contribute $2 million, which will be matched by the Bill & Melinda Gates Foundation to enable officials in developing countries to make evidence-based decisions on the purchase and maintenance of vaccine refrigerators via Coldtrace’s data dashboard.

“Nexleaf’s use of innovative, low-cost sensor technology to support data-driven decision making is the kind of cutting edge work we need to address big global challenges like vaccine delivery,” said Jacquelline Fuller, director of, in a statement. “This new partnership will drive more impact at scale, helping to ensure safe vaccines for everyone.”

Vaccines need to be stored between 2°C and 8°C. If they reach temperatures outside the safe zone, their potency cannot be restored, rendering them ineffective.

According to a 2014 report by the World Health Organization and UNICEF, just two percent of health facilities in low- and middle-income countries have functional cold chain equipment with optimal technology.

“Without a radical shift in the way immunization supply chain systems are designed, managed, resourced and supported, they will remain an obstacle towards reaching every child, and improving vaccination coverage and equity goals in countries,” said WHO and UNICEF in a joint statement.

ColdTrace 5, the current generation device, can operate up to five temperature sensor probes. The device tracks a vaccine refrigerator’s temperature, as well as the clinic’s power availability in real-time. The data is continuously sent to a secure dashboard, which will send mobile text notifications directly to a designated healthcare worker if vaccines reach a danger zone or if the power goes out.

“These text messages, even off hours, lead to actions that preserve vaccine safety,” Nexleaf’s Erin Ross told Laboratory Equipment.

Prior to the implementation of ColdTrace, most health facilities in developing nations relied on stem thermometers or 30-day temperate loggers, which sit in vaccine refrigerators and use a light sensor to show when vaccines are in the temperature danger zone. But they cannot collect or analyze any data, and when the clinic is closed, there is no way for workers to know if something has gone wrong.

ColdTrace provides information on preventative measures, trends, refrigerator make/model performance and power availability history through its secure data dashboard.

As Ross explained to Laboratory Equipment, the ministry of health’s planning committee in a specific country can view data from an individual vaccine refrigerator that has reoccurring issues and determine the cause of those issues. For example, if the data dashboard shows that the clinic where the refrigerator is housed is getting less than eight hours of grid power per day, the committee can allocate funds to obtain a solar refrigerator for that clinic and prevent any further issues.

These informed decisions eliminate the guesswork and ensure allocated funds are being used in the most efficient manner.

The Nexleaf team, led by a trio of co-founders, created the original ColdTrace model in 2012. The following year, Nexleaf was recognized as the first place winner of Vodafone Americas Foundation’s Wireless Innovation Project (WIP). The $300,000 grant helped the company partner with large vaccine delivery organizations like Gavi, expand into international markets, and iterate on the technology in rural clinics and health facilities. Expansion from the grant ultimately led to the most recent partnership with as well.

“That’s the way our technology works—through partnerships with people and organizations in the field,” said Ross.

Nexleaf is now looking to apply the technology of ColdTrace to different sectors—such as blood samples and other non-vaccination, temperature-sensitive medical supplies, as well as the agricultural field. The company’s focus on agriculture would target small-holder farmers in the developing world to keep crops at the correct temperatures and limit post-harvest food loss.

The ColdTrace 5 being used in Mozambique. Photo: Nexleaf Analytics