The covid-19 vaccine cold truth
Manufacturing the
vaccine for global supply is an unprecedented challenge in itself. The facilities
are limited and will need to be scaled up quickly to meet the large-scale
global vaccination needs to achieve the required level of immunity to the
virus.
In the US alone, 70
percent of the population must be immunized to achieve the threshold for herd
immunity.
In India, 900 million need to be vaccinated to reach a herd immunity level
while in Africa the number is pegged at 750 million people, many of whom live
in rural communities with limited access to healthcare.
After manufacture, the COVID-19 vaccine has to go through
a tangled network of freezing, storage, shipping, and distribution – without
budging from narrow, specific temperature ranges – to ensure its quality.
The two leading vaccine
candidates both use an RNA-based technology approach that requires sub-zero
temperature for storage and transportation to prevent degradation. Even though RNA technology is already being used in the treatment of other
diseases such as amyloidosis,no licensed vaccine has been authorized for human use, creating a challenge for
the existing global cold chain industry to maintain such low-temperature
requirements, especially at the scale that is now required.
Moderna’s
vaccine is shipped and stored at -20 ° C (-4 ° F) to reach a shelf life of six
months. Once thawed and kept in a refrigerator between 2 ° C and 8 ° C (36 ° F to 46 ° F), it is only good for up
to 30 days.
Pfizer’s
vaccine must be stored at -70 °C (-94 ° F), which presents a much
greater challenge. Once transferred to a refrigerator, it must be administered
within five days.
As the number of
COVID-19 cases and casualties continues to rise, governments and even private
entities are increasingly hard-pressed to invest in supply chain
infrastructures, cold chain technologies including strengthening cold storage facilities, to ensure
supply and quality of vaccines for wide-scale immunization.