Vaccine vial monitors
Handling vaccines requires great care. All vaccines are sensitive to heat and some to freezing. Careful storage and transport conditions are needed to protect vaccines from harmful temperatures. Imagine the challenge of getting vaccines from a manufacturing facility to the remote settlements in Vietnam, Indonesia or Niger. The vaccines leave the production site in temperature controlled trucks, they are flown as cargo to the country’s capital for storage, then transported deeper into the country, stored again, and finally delivered to the location where they will be administered. Storage facilities often have sporadic electricity or no electricity at all. Transport might be between islands or on dirt roads across rivers, and swamps. Health workers carry the vaccine using trucks, motorbikes, boats, canoes, bicycles and in many cases… on foot. With all these steps, the journey might take a year with the most challenging leg at the very end where the vaccinator struggles to reach populations dispersed by difficult geography, famine, or war. The vaccine is at constant risk of damage.
It is impossible to visually identify when the vaccine is damaged by heat. Therefore, in the past, strict conservative measures had to be used by immunization programmes that resulted in often unnecessary disposal of loads of vaccines whenever heat exposure was suspected. In the past, heat damaged vaccines could have also gone unnoticed. Health workers at remote locations had to blindly rely on others who handled the vaccine before it reached them. If errors occurred, heat damaged vaccines may have been given to children leaving them unprotected from disease.
A vaccine vial monitor, or VVM, is a circular indicator, printed directly on the vaccine vial label or affixed to the top of the vial or ampoule. The inner square of the VVM is made of heat-sensitive material that is initially light in colour and becomes darker when exposed to heat over time. By comparing the colour of the square to the reference ring, health workers can determine the extent to which the vaccine has been exposed to heat. The vaccine can be used as long as the colour of the inner square is lighter than that of the reference ring.
This simple, yet elegant, tool indicates whether the vaccine has been exposed to a combination of excessive temperature over time and whether it is likely to have been damaged. It clearly indicates whether a vaccine can be used. This is why health workers today feel very confident. Now they rely on what they see. Now they make informed decisions based on interpretation of VVM indicators.
VVM ensures that the administered vaccine has not been damaged by heat. It is estimated that over the next ten years VVM will allow health workers to recognize and replace more than 230 million doses of unusable vaccines. VVM reduces wastage, saving annually around 5 million USD worth of vaccines. VVM facilitates immunization outreach and increases immunization access and coverage. With VVM, over the next ten years health workers will be able to deliver more than 1.5 billion more doses in remote settings including delivering the birth dose of hepatitis B vaccine to millions of newborns in hard-to-reach areas. VVM pinpoints cold chain problems and helps to effectively manage vaccine stocks - store keepers and immunization managers now adopt VVM based vaccine management, making decisions with the help of VVM readings.
VVM shapes the future of cold chain today, a future in which dependency on the cold chain is removed. Today, VVM is seen as a catalyst for much-needed changes in strategies of vaccine distribution via the cold chain. VVM allows immunization programmes to exploit the stability of each vaccine to the greatest possible extent, minimize distribution costs, and increase flexibility in the handling of vaccines in the field, thus helping to make operations more effective.
Although developed as a heat-exposure indicator, VVM also contributes significantly to the reduction of vaccine freezing. VVM makes it possible to detect and avoid excessive heat exposure to vaccines when methods are employed to store and transport vaccines without ice and equipment that is a known source of freeze damage. VVM allows health workers to feel confident that a load of vaccines does not necessarily go bad if the power fails for a night . VVM allows health workers to see the heat stability of vaccines and accept the fact that freezing is a greater danger than mild heat exposure.
Conceived as a dream in 1979, today the availability of the VVM is the result of immense efforts and dedication to strengthening public health on the part of many organizations, institutions, companies and individuals. Without VVM, health workers can rely only on the expiry date of a product. But when you are buying a bread in a bakery, besides seeing how fresh the bread is, you can smell it, you can touch and feel it, listen to the crispy sound it makes, and taste it. VVM expands the horizon for all immunization programmes, VVM is a “five senses” offer to health workers, although they only look at it, with VVM health workers discovering things other than a printed expiry date, as if they feel, hear, smell and taste… and they know with confidence which vaccine can be used or not… VVM expands the horizon for all immunization programmes, wherever the challenge is. It offers a railroad, a bridge, a tunnel, a motorbike, a canoe, a bicycle, and a pair of shoes to reach the unreachable.