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Marco Ugarte / AP
It’s happening: Mexican military health workers expect to be vaccinated against Covid-19 in Mexico City last week.
OPINION: As I write, it has been almost a year since the first reports emerged of the mysterious disease that we now know as Covid-19. Twelve months later, the virus responsible, SARS-CoV-2, has turned the world upside down.
But in that time, we’ve also made incredible progress in developing vaccines for Covid-19. We have gone from nothing to nearly 20 in phase III clinical trials, some of which are now rolling out around the world. It is a great achievement and a testament to what we can achieve when enough money and people are dedicated to a problem.
The proven ways of making vaccines involve giving people a dead or weakened version of the infectious microbe, or the parts of it that we want our bodies to learn to recognize. But the Pfizer / BioNTech and Moderna vaccines being rolled out now take a completely different approach.
They turn our own bodies into vaccine factories.
If the approach turns out to be safe and effective, and things look very promising, it will revolutionize the way we design and manufacture vaccines in the future.
READ MORE:
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* Covid-19: How does the Pfizer vaccine destined for New Zealand really work?
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How do we turn our bodies into vaccine factories? Inside our cells there is a compartment called the nucleus where our DNA lives. That DNA is the instruction manual for creating the proteins we need to grow and function.
Frederic Sierakowski / AP
Healthcare workers inspect vials of the Pfizer-BioNTech COVID-19 vaccine as they are thawed in a Belgian laboratory. Thawing the vaccine is the second step in the process before it can be administered to patients.
DNA cannot get out of the nucleus. Instead, it becomes a set of instructions that can be output, called “messenger RNA” or mRNA. That mRNA leaves the nucleus, goes to the protein-making structures of our cell to be translated into proteins, and then degraded.
The advantages are that it is relatively fast, easy, and safe to produce mRNA. The downside is that mRNA is unstable, so while it can last a long time in the freezer, it degrades fairly quickly at room temperature.
The Pfizer / BioNTech and Moderna vaccines are synthetic fragments of mRNA designed to make our cells make the peak protein of the SARS-CoV-2 virus. That is the part of the virus that we want our body to recognize, so when we encounter the real virus, our immune system will protect us from it.
Scientific breakthroughs like this don’t come out of nowhere. Messenger RNA was first discovered in the early 1960s, but it wasn’t until the late 1980s that scientists learned how to make it from scratch.
Then a new obstacle arose. When the scientists injected mRNA into animals, it induced such a severe immune response that the animals died.
It was Dr. Katalin Kariko, in collaboration with immunologist Dr. Drew Weissman, who discovered how to prevent that severe immune response from occurring. And that was crucial for mRNA vaccines to be tested in humans.
RICKY WILSON / Stuff
Science columnist Dr. Siouxsie Wiles stuff.
Kariko made her discovery despite having rejected all of her requests for research funding. It was even demoted by the University of Pennsylvania for failing to attract funding. However, she persisted.
And thank goodness he did. Kariko has been at the forefront of the development of BioNTech’s Covid-19 vaccine. We owe you a debt of gratitude.
Dr Siouxsie Wiles MNZM is Associate Professor at the University of Auckland and Deputy Director of Te Pūnaha Matatini, a New Zealand Research Center of Excellence.
