Availability of Vaccine Vial Monitors is Critical in Low and Middle-Income Countries
Vaccine Vial Monitor & Global Health
As far back as thirteen years ago, in 2007, the World Health Organization (WHO) and the United Nations International Children Emergency Fund (UNICEF) issued a joint policy statement about vaccine vial monitors (VVM) as an essential in improving the immunization process.
The first point of the joint policy statement summarizes the importance of VVM:
“At any time in the process of distribution and at the time a vaccine is administered, the vaccine vial monitor (VVM) 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 to health workers whether a vaccine can be used.”Vaccines and Immunization – WHO
VVMs are used by medical teams to warn health care workers if heat has damaged a vaccine. The monitors have a light-colored, heat-sensitive material that darkens when exposed to heat over a period of time, an indication that the vaccine is no longer effective.
WHO first introduced the idea of VVMs in 1979. The first vaccine they tested using a VVM was a measles vaccine using a p-toluenesulfonate chemical. A product development program was launched, led by the Program for Appropriate Technology in Health (PATH). The target price of VVMs at that time was 5 cents per vial.
In 1994, WHO, UNICEF, and oral polio vaccine pharmaceuticals concluded that VVMs must be used in all oral polio vaccines. Consequently, it’s pilot VVM program was introduced in Tanzania and Vietnam in 1995.
Immunization is a global health need that saves millions of lives every year.
Vaccines reduce the probability of disease infecting an individual by working with the body’s natural defenses to build protection. The immune system is stimulated to respond to the vaccine.
To date, there are vaccines that prevent more than twenty life-threatening diseases and prevent 2 to 3 million deaths annually from diseases such as diphtheria, tetanus, pertussis, influenza and measles.
Since vial monitoring is an indispensable element to ensure the potency of the vaccine and its recipients’ safety, the joint policy issued by WHO and UNICEF “urges all member countries with access to self-procuring vaccines to use VVMs as well the minimum requirements for vaccine purchase agreements.”
The statement recommends that all member states adopt vaccine management practices that include.[i]
- Ensuring that vaccines administered have not been damaged by heat.
- Reducing vaccine wastage.
- Facilitating immunization outreach and increasing access and coverage.
- Pinpointing cold chain problems.
- Managing vaccine stocks.
- Preventing inadvertent freezing of vaccines.
VVMs react based on the level of heat stability.
Vaccines from the VVM 30 high-stability category last 30 days at 37°C, 193 days at 25°C and at least four years at 5°C.
Vaccines from the VVM 14 medium-stability category last 14 days at 37°C, 90 days at 25°C and at least three years at 5°C.
Vaccines from the VVM 7 moderate-stability category last seven days at 37°C, 45 days at 25°C and at least two years at 5°C.
Vaccines from the VVM 2 least-stable category last two days at 37°C and 225 days at 5°C.
Low-and Lower Middle-Income Countries and VVM
The Global Alliance for Vaccines and Immunization (Gavi) assumes the responsibility of vaccine financing and procurement for lower-income countries. Many of these countries, however, are transitioning from dependence on Gavi to autonomy in terms of immunization. It is unclear if VMM would still be available to these governments to procure vaccines outside the Gavi initiative.
Before joint research and studies by independent organizations, WHO-UNICEF had already validated the merits of VVM, as stated in the supplemental information of their joint policy:
The impact of VVMs on field operations, both routine and supplemental, has been assessed in Bhutan, Ghana, Kenya, Nepal, Sudan, Tanzania, Turkey, and Vietnam. The studies show that polio vaccine may be taken successfully beyond the reach of the cold-chain infrastructure during national immunization days in remote areas and that vaccine wastage rates are reduced. They also show that the VVM detects areas where the cold chain is weak and focuses measures to strengthen the cold chain in those areas where reinforcement is needed. [i]
An excellent reference on this subject is a joint systematic review of VVM conducted by Pär Eriksson, Bradford D. Gessner, Philippe Jaillard, Christopher Morgan and Jean Bernard Le Gargasson, entitled Vaccine Vial Monitor Availability and Use in Low-and Middle-Income Countries: A systematic Review.
Their paper reviewed the evidence on VVM availability and use in low and middle-income countries. The objective was to document factors that influenced access to, and demand for, VVMs. Outcomes of the research could help identify solutions to ensure the use of VMMs for countries transitioning out of the Gavi support program.
The results of the synthesis may be summarized as follows:
- Multiple sourcing of vaccines affected the availability of VMMs and the extent of its inclusion in vaccine specification and documentation during procurement.
- There is high-knowledge about VMM and its impact on the Extended Program on Immunization (EPI among decision-makers and health workers.
- Some transitioning countries, or those who graduated from Gavi have weak procurement capacity and are likely to impact the demand for VMM.
- Disease burden and vaccine price takes precedence over vaccine characteristic and presentation.
- Country governments are decidedly dependent on the recommendations and advice of the World Health Organization and the Pan American Health Organization (PAHO).
An excerpt of regional assessment and result of the studies found:
That though Gavi-eligible countries had access to VVM- labeled vaccines, the degree of VVM inclusion on vaccines varied across regions and countries. VVM inclusion was most common in Africa (AFRO region) where 84% of estimated vaccine doses in routine immunization programs carried VVMs. Despite this high regional average, some countries had much lower rates of VVM inclusion on their vaccines, notably Mauritius, Seychelles, South Africa and Mozambique. In the Eastern Mediterranean region, VVM inclusion on vaccines was 82%, while it was lower in South- east Asia (56%) and Western Pacific (30%) regions. This study found that low VVM inclusion was associated with high rates of self- procurement and VVM not being included in vaccine specification in tender documents. [ii]
Conclusions indicated that WHO and UNICEF play significant roles in global access to, and country demand for, VMM. Through its policies, these worldwide health and funding institutions influence country governments in VMMs procurement.
Countries outside Gavi with weak institutional capacities need to strengthen the implementation of their health policies geared towards vaccination and its procurement process.
Decision-makers, health workers, and ground personnel involved in the cold chain must undergo training, especially in transition countries with a high demand for VMMs.