It is estimated that vaccination programs save about 3 million lives worldwide from the adverse impact of infectious diseases. However it is also reported that about 3 million individuals succumb to vaccine –preventable diseases and the fact that many vaccines not being thermo stable plays a part in this tragedy.
The World Health Organization (WHO) estimates that annually 10-50 percent of vaccines may be wasted globally because of temperature control, logistics and shipment-related issues.
The vaccines currently available need to be kept constantly cold at temperatures between 2°C to 8°C from the point of manufacture until reaching the recipient. Considering the variable stability of vaccines, for a country like India, which experiences a tropical climate, the cold chain remains a highly vulnerable point. Low resource setting areas, which are not only isolated but lack reliable electricity for refrigeration, pose a major obstacle. This impacts the overall immunization rates negatively.
Storage of vaccines at optimum temperature is critical. Inadequate refrigeration systems lead to unintended interruption of the cold chain. Further lack of quality monitoring apparatus, exposure to high heat and damaging exposure to temperatures below 0°C harm the vaccine efficacy. Currently, the requirement for a vaccine to be transported and stored in a constant cold chain, from the time it leaves the manufacturer until it is used at a vaccination point, places huge logistical challenges on vaccination providers who must ensure that the cold chain is maintained each step of the way.
Development of thermo stable vaccines, vaccines that can withstand elevated or fluctuating temperatures is an emerging thought. Use of thermo stable vaccines has the potential to ease such logistical hurdles imposed by the ‘cold chain’. Thermo stable vaccine formulations that would be resistant to damage caused by freezing or excessive heat can reduce the dependence on the cold chain.
Benefits of thermo stable vaccines are huge, including cost savings, preventing vaccine damage, and, most importantly, making it easier to reach children living in remote places who would otherwise remain unvaccinated.
A clinical study published in “Vaccine” in the year 2012; by Lee BY et al has another interesting perspective, “Eliminating the need for refrigerators and freezers should not necessarily be the only benefit and goal of vaccine thermo stability. Rather, making even a single vaccine (or some subset of the vaccines) thermo stable could free up significant cold storage space for other vaccines, and thereby help alleviate supply chain bottlenecks that occur throughout the world.
Nevertheless, making individual vaccines thermo stable could still have benefits if their removal from the cold chain could relieve bottlenecks in the vaccine supply chain.”
Read more:
http://apps.who.int/iris/bitstream/10665/64980/1/WHO_GPV_98.07.pdf)
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