Challenges and Solutions in Off-Grid Vaccine Maintenance
Maintaining temperatures on and off the grid to preserve vaccines is a known issue in the pharma cold chain. Keeping heat-sensitive vaccines at the right temperature is imperative, yet very difficult in locations with unstable or no electrical power.
Vaccines are valuable life-saving drugs that boost the human body’s immunities to protect it from infectious diseases like polio, measles, smallpox, mumps and rotavirus, among many others.
Unfortunately, despite concentrated and organized efforts from the World Health Organization and United Nations member countries, almost 20 million people are at risk of contracting preventable diseases because of under-vaccination. Consequently, around 1.5 million children die every year from diseases that can be prevented by vaccination.
Geo-political issues, wars, government mismanagement, bureaucracy, lack of infrastructure, and corruption are among the reasons that prevent health organizations from attaining their vaccination targets. These challenges are significant contributors to vaccine wastage, leading to the under-vaccination of children.
According to the World Health Organization, over 50% of vaccines are wasted around the world. Although there are tools and systems for efficient cold storage, the wastage rate remains high, even in developed countries.
newsGp reported that “at least $25.9 million in Australian vaccines has been lost to cold chain breaches since 2014, but incomplete government statistics mean the final total could be much higher.”
The news article stated that more than 12,000 cold chain breaches were recorded nationwide over the past five years, resulting in at least 747,000 destroyed vaccines, or 1.65% of the total distributed. The report mentioned that failure to maintain cold storage temperatures is one of the causes of vaccine wastage.
Vaccine Preservation in Off-Grid Environments
The availability of systems and tools does not ensure efficient cold storage since its effectiveness also depends on varied uncontrollable factors such as electric power loss, or lack of power initially.
Health workers are required to discard corrupted vaccines exposed to heat. Most rural areas in developing countries don’t have a steady power supply and are incapable of keeping vaccines in refrigerated storage systems. The challenge is like keeping an ice cream cone from melting under the sun.
An efficient cold chain relies on electricity. Vaccines must be kept in a temperature-controlled supply chain from their production, right up to the administration to recipients. The handling protocols require a temperature between 2°C and 8°C during storage. Vaccines may lose their potency during power outages due to extreme heat exposure.
Alternative Cold Chain Solutions
Cold chain system manufacturers produce passive and mobile coolers for long-term storage, to offset the reliance on the electric power supply. Cooled either by ice packs, batteries, or solar, portable storage “boxes” can store vaccines at ideal temperatures. Several Asian and African countries are using some models for evaluation and show promising results.
Stationary Passive Coolers
The Vietnam National Expanded Programme on Immunization used and evaluated the Nano-QTM, a US-made device, manufactured by Savsu Technologies. This device uses state-of-the-art insulation materials, uniquely configured to maintain the correct temperature for vaccine storage without an electrical power source.
The health agency of Vietnam used Nano-QTMs in small health centers that usually don’t have vaccine refrigerators. After a period of usage, the devices provided seven days of cooling at an outside temperature of 32°C, after which technicians replenished the ice packs.
Health workers tested twelve other devices in Vietnam for periods ranging from four to eight months. Technicians and researchers monitored the temperature of the passive cold storage boxes. They also conducted interviews to get user feedback.
Based on the evaluations, the stationary passive storages are capable of maintaining storage temperature over long periods. In addition to this, user compliance to the replenishment of ice packs procedures resulted in effective cold storage, even without electricity-powered devices.
Health workers gave positive evaluations and cited the ease of monitoring temperature and the mobility of the storage. They also noted the practicality of using ice packs in maintaining the ideal storage temperature.
At the time of the testing of the Nano-QTMs, only a few community health centers were capable of providing vaccine cold storage for a full month. To remedy this problem, logisticians delivered vaccines one or two days before immunization.
Vaccines, however, such as for Hepatitis B, must be available throughout the month so health workers can vaccinate babies at birth. Thus, stationary passive storage systems are timely and practical for socio-economic locations similar to Vietnam.
Mobile passive coolers
Just as in Vietnam, Senegal launched a project to evaluate the impact of innovative pharma cold chain systems. Its government tested Dometic RCW25 Vaccine Carriers with PCM packs for transport and Aircontainer Package System Big Box.
Health workers used these storage boxes like “moving warehouses” to transport and deliver vaccines. The truck that carried passive mobile units traveled from a regional pharmaceutical store to St. Louis’s health centers on a monthly schedule.
The PCM packs in RCW25 Vaccine Carrier, with PCM packs for transport and Aircontainer Package System Big Boxes act as a passive cooling storage alternative to ice packs. When solidly frozen, it is similar to ice, but retains more cooling power when it reaches the melted liquid phase.
Tests showed that PCM packs are effective in cold storage because they can maintain the vaccine temperatures safely. They also save space and allow vials to fill the entire box.
Some issues, however, arose about the Bigbox-container during its pilot use because its PCMs could not be refrigerated in Senegal. The protocol required 36 hours of freezing and 24 hours of conditioning before use.
Consistent and well-managed protocol compliance solved the issues of freezing and conditioning. The assessors aired their recommendation to the manufacturers to upgrade the hinges, locks, and inner insulation of the box to enforce its cold storage capabilities.
Other Solutions Under Development
“Last Mile” Delivery Drones
The term “last-mile delivery” refers to deliveries made during the final leg of the chain. Logisticians usually make such deliveries through adverse geographical locations that lack roads or infrastructures.
Health logistic workers face the challenge of delivering vaccines in far-flung rural areas with isolated communities. Natural disasters such as earthquakes and typhoons compound logistical problems because they make roads more inaccessible due to damage. In some cases, human factors like banditry, civil conflicts, and wars make cold chain deliveries more difficult.
Given such circumstances, heavy-duty and state-of-the-art delivery drones can be used to deliver vaccines. Health workers still must follow storage protocols when delivery drones are in flight, to ensure that boxes maintain the correct temperatures.
For now, medical workers are using drones for the delivery of medicines as reactive solutions during emergencies. Researchers are studying the development of vaccine delivery drones that adhere to health logistic protocols.
Solar refrigerators for power supply
Like cargo drones, medical logisticians perceive solar-powered refrigerators as cost-effective and game-changing solutions for off-grid locations. In April 2016, ICRC installed solar panels in the Gaza Strip to power vaccine refrigerators in 32 healthcare clinics.
The use of solar refrigerators dates back to the early 1980s during the Expanded Program on Immunization by the World Health Organization. By 2006, the organization had installed fifty solar refrigerators worldwide to solve off-grid vaccine storages.
UNICEF favors using solar power to replace conventional alternative power sources that use gasoline or kerosene for environmental and practical reasons. Medical workers successfully used solar-powered refrigerators in Nigeria and Burkina Faso.
Solar-powered refrigerators, however, are far from being perfect. According to studies, they still lack adequate monitoring of temperature performance and management protocols to detect deviations or disruptions.