From a Rush job, obviously could happen.
What are problems with mRNA?
MRNA technology isn’t new. It was
shown a while back that when synthetic mRNA is injected into an animal, the cells can produce a desired protein. But the progress remained slow. That’s because mRNA is not only notoriously unstable and easy to degrade into smaller components, it is also easily destroyed by the human body’s immune defenses, which make delivering it to the target very inefficient.
But beginning in 2005, researchers figured out how to stabilize mRNA and package it into small particles to deliver it as a vaccine. The mRNA COVID-19 vaccines are expected to be the first using this technology to be approved by the FDA.
After a decade of work, the mRNA vaccines are now ready for evaluation. Physicians will be watching for
unintended immune reactions, which can be both
helpful and
detrimental.
Why keep mRNA supercold?
The most important challenge for development of a mRNA vaccine remains its inherent instability, because it is more likely to break apart above freezing temperatures.
Modification of the mRNA building blocks and development of the particles that can cocoon it relatively safely have helped the mRNA vaccine candidates. But this new class of vaccine still requires unprecedented freezer conditions for distribution and administration.
What are the refrigeration requirements?
The Pfizer-BioNTech mRNA vaccine will need to be optimally stored at minus 94 degrees Fahrenheit and will degrade in around
five days at normal refrigeration temperatures of slightly above freezing.
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In contrast, Moderna
claims its vaccine can be maintained at most home or medical freezer temperatures for up to six months for shipping and longer-term storage. Moderna also claims its vaccine can remain stable at standard refrigerated conditions, of 36 to 46 degrees Fahrenheit, for up to 30 days after thawing, within the six-month shelf life.
Not surprisingly,
Pfizer is also developing shipping containers using dry ice to address shipping constraints.
There are two new COVID-19 vaccines that appear to be more than 90% effective. But what are these vaccines, and how are they different from those used previously?
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