Many

vaccines A vaccine is a biological preparation that provides active acquired immunity The adaptive immune system, also known as the acquired immune system, is a subsystem of the immune system that is composed of specialized, systemic cells and pro ...

require refrigeration to remain active, and the lack of infrastructure to maintain the

cool chain A cold chain is a low temperature-controlled supply chain network. An unbroken cold chain is an uninterrupted series of refrigerated production, storage and distribution activities, along with associated equipment and logistics, which maintain qu ...

to reliably bring vaccines into more remote areas of developing countries poses a serious challenge to national immunization programs. Post millennium, a portable vaccine cooler unit has been proposed by several technologists. The

WHO Who or WHO may refer to: * Who (pronoun), an interrogative or relative pronoun * Who?, one of the Five Ws in journalism * World Health Organization Arts and entertainment Fictional characters * Who, a creature in the Dr. Seuss book '' Horton He ...

Performance, Quality and Safety (PQS) programme is a driver of the technology. __TOC__

Technology development

In 2005 Ian Tansley of Sure Chill designed an ice-chest vaccine cooler regulated by the density of water. Since water has greatest density at around 4 °C, putting the vaccine chamber at the bottom of a thermo-syphon regulates the temperature at between 2 °C and 8 °C, as long as there is ice and the heat-exchange capacity is not overloaded. Sure Chill claimed to be WHO approved and in use for

vaccine storage Vaccine storage relates to the proper vaccine storage and handling practices from their manufacture to the administration in people. The general standard is the 2–8 °C cold chain for vaccine storage and transportation. This is used for all ...

in 46 countries. A refrigeration device was shown for this purpose by

Adam Grosser Adam; el, Ἀδάμ, Adám; la, Adam is the name given in Genesis 1-5 to the first human. Beyond its use as the name of the first man, ''adam'' is also used in the Bible as a pronoun, individually as "a human" and in a collective sense as " ...

at a

TED Talk TED Conferences, LLC (Technology, Entertainment, Design) is an American-Canadian non-profit media organization that posts international talks online for free distribution under the slogan "ideas worth spreading". TED was founded by Richard Sau ...

in 2007, but had not been produced commercially as of 2020. Grosser's proposed device uses exposure to a cooking fire for 30 minutes to store heat. After a cooling period of an hour, the device is placed into a 15-litre container, which contains the vaccine. His concept calls for a 24-hour re-cycle period. It was revealed in March 2008 that another class of long-term Vaccine Cooler is based around an Ice Box with separate Ice and Vaccine chambers. Using ice as the energy storage device allows the Vaccine Cooler to operate for long periods without power: separating the vaccine chamber from the ice chamber allows temperature regulation while avoiding the need for special packing and conditioning of the cold packs. Suggestions have included the use of a regulated heat pipe to connect the vaccine chamber and the ice chamber. In September 2008 it was reported that Malcolm McCulloch of

Oxford University Oxford () is a city in England. It is the county town and only city of Oxfordshire. In 2020, its population was estimated at 151,584. It is north-west of London, south-east of Birmingham and north-east of Bristol. The city is home to the ...

was heading a three-year project to develop more robust appliances that could be used in locales lacking electricity, and that his team had completed a prototype of his renewal of the

Einstein refrigerator The Einstein–Szilard or Einstein refrigerator is an absorption refrigerator which has no moving parts, operates at constant pressure, and requires only a heat source to operate. It was jointly invented in 1926 by Albert Einstein and his form ...

. He was quoted as saying that improving the design and changing the types of gases used might allow the design's efficiency to be quadrupled. The three working fluids in this design are

water Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a ...

ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous was ...

and

butane Butane () or ''n''-butane is an alkane with the formula C4H10. Butane is a gas at room temperature and atmospheric pressure. Butane is a highly flammable, colorless, easily liquefied gas that quickly vaporizes at room temperature. The name but ...

. The Free Piston Stirling Cooler, a type of mechanical refrigerator, was brought to market before 2010 by

Twinbird Corporation Twinbird Corporation, founded in 1951, is a manufacturer of household electric products with headquarters in Tsubame City, Niigata Prefecture, Japan. Shigekatsu Nomizu is the President, employing 284 people as of March 2010. It was founded as ...

of Japan. In 2016 Will Broadway won the James Dyson Award for a vaccine cooler based on a miniaturisation of the bi-fluid

Icyball Icyball is a name given to two early refrigerators, one made by Australian Sir Edward Hallstrom in 1923, and the other design patented by David Forbes Keith of Toronto (filed 1927, granted 1929), and manufactured by American Powel Crosley Jr., ...

technology. Broadway's design uses

electricity Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described ...

propane Propane () is a three-carbon alkane with the molecular formula . It is a gas at standard temperature and pressure, but compressible to a transportable liquid. A by-product of natural gas processing and petroleum refining, it is commonly used a ...

as the heat source. As of August 2019, Broadway claimed an 88-hour cool-life under WHO PQS test conditions, whereas competitor products could only meet a nine-hour cool-life.

References

{{reflist Vaccination Cooling technology Heating, ventilation, and air conditioning Gas technologies