By Kadeem Joseph
The Pfizer vaccine appears to be the shot that will be provided through the World Health Organisation’s Covax facility during its initial rollout.
Information Minister Melford Nicholas made the disclosure during Thursday’s post-Cabinet briefing based on reports from the Minister of Health Molwyn Joseph.
The minister was quick to remind the nation of the challenges the vaccine may pose since it is required to be stored at a bone-chilling minus 70 degrees Celsius.
“We think we have identified a facility that can support that regime,” Nicholas said.
The government had also indicated plans to acquire the necessary refrigeration equipment for the proper storage of the vaccine should it become available, with the latest projection being for distribution to start in March or April.
Nicholas said early doses will first be given to frontline workers and those who provide “security and service” to the population, followed by a national rollout as more become available.
The minister said while the Pfizer vaccine may be the first approved under the initiative, others may be approved thereafter.
The Covax facility is a global initiative that brings together countries from across the world and manufacturers to ensure that Covid-19 vaccines reach those in greatest need, whoever they are or wherever they may reside.
Understanding why these unique conditions are needed for these vaccines requires an appreciation for how they were developed and ultimately designed to work.
The need for freezing temperatures for storage is not limited to the Pfizer vaccine; the inoculation developed by Moderna also requires cold storage, albeit at a higher temperature of minus 20 degrees Celsius (closer to the temperature of a regular freezer).
Both vaccines use a new approach that shortens the time it takes for scientists to develop them.
Developers used messenger RNA (mRNA), which, in essence, carries the genetic code that will allow a patient’s cells to produce a protein unique to the novel coronavirus.
When the body recognises this protein, an immune reaction is triggered. This means that specialised cells not only remember this protein but also carry the information required to appropriately launch an attack against the Covid-19 virus, which carries the protein, if it enters the body in the future.
But while these vaccines can be made much faster, the draw back is: these small particles are much more fragile than the vaccines that we are accustomed to, according to the scientific community.
Although these mRNA particles are stabilised with nanoparticles and a lipid or fatty coat, they remain sensitive.
Imagine an ice cream popsicle with a chocolate coat – the ice cream on the centre being the mRNA and the chocolate coat representing the stabilisers. While the delicious chocolate exterior may allow you to enjoy or control the ice cream centre more easily, with enough time outside of cold storage, the ice cream still melts.
Pfizer has, however, developed packaging designs that allow for the safe travel and short-term storage of the vaccine, noting that with dry ice the vaccines can be stored for five days before refreshing the ice required.