With the outbreak of the COVID-19 pandemic, and subsequent the roll out of the vaccination program in 2021, cold chains have become a concept that a lot of people have become familiar with.
We already talked about the Cold Chain in a previous post
that you can read in the below link:
But with this term now becoming a hot topic, a post of
itself should be dedicated to vaccines specific cold chain!
Let’s start from the beginning; a cold chain is a temperature-controlled Supply Chain. In particular, the term is used to describe the cold temperature
conditions in which certain products need to be kept during storage and
distribution.
The cold chain is
used in the supply and storage of many perishable products, including vaccines, however, maintaining a continuous cold chain in
resource-limited places where power supply is unreliable, or even non-existent,
is a considerable task.
For vaccines,
there are different types of requirements.
- There is an ultralow, or deep freeze, cold chain for vaccines that
require -70 degrees C (the Ebola vaccine require this level).
- Next the frozen chain requires -20 degrees C (varicella and zoster
vaccinations require this level)
- The refrigerated chain, which requires temperatures between two and
eight degrees C (most flu vaccinations only require refrigeration).
As an anecdote,
the Pfizer COVID-19 vaccine also needs ultracold storage and transportation temperatures as cold
as −70 °C, requiring what has been referred to as a "colder chain
infrastructure” which has created some issues of distribution as it is
estimated that only 25 to 30 countries in the world have the infrastructure for
the required ultracold cold chain.
If you want to
see first-hand how critical cold chain is when distributing vaccines, I
recommend watching the series Cold Chain missions, with Ewan McGregor. Here is
a taste for it:
Cold Chain Mission - The Congo
And if you
want more information, check the below document from the World Health
Organisation on vaccines cold chain.
