As the global COVID-19 pandemic has turned our attention to the importance of vaccines and the cold chain distribution process, additional problems have come to light. The major concern, in particular, is the poor conditions of the immunisation cold chain in developing countries. This supply chain process was placed under scrutiny by world influencer and champion, Bill Gates, who previously shared this illustration to highlight points in the cold chain that need to adhere to strict temperature regulation to ensure a useful end product.
Vaccines are fragile. They must be maintained at the defined temperatures recommended by vaccine manufacturers and protected from light at every link in the cold chain. Most live virus vaccines are intolerant to freezing temperatures and their efficacy deteriorates rapidly after they are removed from the cold chain process. The potency can be adversely affected if vaccines are left out too long or exposed to multiple temperature excursions (out-of-range temperatures) that can have a cumulative negative effect.
These storage and handling errors can occur at any stage during the transport process, which ends up costing thousands of Rands in wasted vaccines and revaccination, or worse, unprotected children. Even if the shelf life of the vaccine is within tolerance, a poor cold chain managed product could result in ineffective immunisation.
To address these issues, the World Health Organization (WHO) and United Nations International Children’s Emergency Fund (UNICEF) have consistent guidelines regarding vaccine management. In the context of the COVID-19 pandemic, the guidelines are expanded to integrate the storage and transport of temperature-sensitive COVID-19 therapeutics, laboratory reagents and test kits in the vaccine cold chain system.
In broad language, it is recommended that two provisions be met to ensure the protection of vaccines. Firstly, to maintain storage practices of goods. And secondly, to clearly label and separate non-vaccine product from vaccine and diluents at all times.
It is highly stressed that if the existing capacity is not sufficient to accommodate all appropriate temperature-sensitive health products, or if the required storage temperatures are outside the usual ranges available for storing vaccines, countries are advised to explore options to manage surplus stock.
This would include:
- Prioritising items to be stored in the equipment for vaccines storage and transport cold chain (vaccines should be prioritised)
- Adjusting distribution frequency based on cold chain capacity and utilisation rate
- Using any available and functional WHO prequalified cold chain equipment
- Commissioning of private cold chain facilities where the temperature can be maintained to safely store the products
The onus is on our healthcare services to ensure that the vaccines walk this long road with high levels of temperature regulation at each point of the cold chain. The alternative would see countries spend a lot on vaccines that do not yield the expected results.