The Weakest Link

The cold chain has made considerable progress in recent years in the field of health products. Efforts have been made by various interested parties – pharmaceutical laboratories, inspection and standards organisations, distributors, pharmacists, logistics experts and problem solvers – to provide greater control over and improved management of cold chain logistics. The aim is to provide the patient with a product that has retained all of its therapeutic qualities, and a lot of money has been spent on reaching that objective. Although there has been some success between manufacturing the product and the dispensary, the final segment of the chain, which is often in the hands of the patient, is still difficult to control and qualify. This is the weak link in the cold chain. What happens when the patient leaves the pharmacy with his vaccine to go home or to the doctor’s surgery? How does he carry the vaccine? And, more importantly, has the product retained all of the required qualities when it comes to be administered?

A PRODUCT WITH VERY LOW THERMAL INERTIA

Medicines have low thermal inertia, often 10 per cent lower than that of water. Its temperature can vary rapidly depending on the surrounding environment in which it finds itself. It only takes a few minutes for a vaccine to leave its required temperature range once exposed to heat or cold without protection. As a result of such changes, some products can deteriorate or lose their effectiveness.