The science stars of the year, RNA vaccines, are not as radically new as we think.
For starters, RNA is surely the oldest informational molecule on the planet.
"Informative" means that it has genes, and that implies two essential properties: that it makes copies of itself and that it means something.
In our days it is DNA that embodies these two functions, but everything points to RNA as its holder at the origin of life, about 4,000 million years ago.
Neither is its use as a vaccine an invention fallen from the sky, since it has been curdling in basic research laboratories for 30 years.
None of that detracts from her starring role in the pandemic, but it does help frame things on their correct timescale.
The first demonstration of the messenger RNA technique (mRNA in its universal acronym) used by Pfizer and Moderna vaccines has just turned 30 years old.
A team from the Department of Pediatrics at the University of Wisconsin, Madison, published
the proof of principle
in
Science
, showing that direct injection of mRNA into the muscle of mice caused the cells to read the gene that had been incorporated into the mRNA. .
They used genes from several easily detectable products, including luciferase, the protein that makes fireflies glow, and whose demonic name has promoted
untold fakes
in anti-
vaccine
lies.
This was just an initial experiment, intended as a proof of principle.
The Pfizer and Moderna vaccines do not carry the luciferase gene, but rather the SARS-CoV-2 spike gene.
The mRNA enters our cells, our machinery produces the spike protein, exposes it on its surface, and the immune system reacts against it.
This is how you are prepared in case the natural virus arrives later.
What has happened in these 30 years?
That, as usual, a lot of technical problems had to be solved in order for the proof of principle to reach the clinic.
RNA is a very fragile molecule, and the enzymes that destroy it (called RNases) are in our saliva, our sweat, and everywhere else.
We have had to find ways to protect it, to wrap it in products that isolate it from that hostile world.
Furthermore, it has to penetrate our cells if it wants to do something, and the inefficiency of that process disables it as a useful vaccine.
So there has also been a need to improve the ability of the particles to cross the cell membrane.
These difficulties had diverted the attention of researchers, and those who finance them, to the more established vaccines, based on the whole virus or some of its parts.
Some vaccines that cannot infect
Great strides have come in the last decade, mostly thanks to increased investment in the field.
The reason is that funders perceived that mRNA vaccines had several important advantages over their competitors.
And, curiously, given the doubts that the Pfizer vaccine has raised among the population, the main one was safety.
The mRNA carries information, but it cannot be replicated, therefore it is not an infectious entity.
It also cannot insert into the human genome, or any other, which eliminates the possibility of insertional mutations of viral material.
In addition, its life is rather short, because we have a whole cellular machinery dedicated to degrading it in a controlled way.
And, as we've just seen live, it can be developed very quickly and efficiently manufactured on a large scale.
At the beginning of 2018, two years before the pandemic, the technique was ready for use, and not only for vaccines, but also against cancer.
The rest is about to be history, or so scientists hope.
The rapidity of development of Pfizer and Moderna vaccines has puzzled experts.
The fastest vaccine ever made, the mumps vaccine in the 1960s, took four years from virus isolation to approval.
And that is the record, because the most common is to take a decade.
This time it has been only one year.
This speed record raises an obvious question: will we be able to develop a vaccine in one year from now on?
Not only is the speed mark a reason to congratulate biomedical research, it also raises an almost obvious question: can we develop a vaccine in a year from now?
It is interesting, because virologists are convinced that more pandemics of new emerging viruses will come.
Given what SARS-CoV-2 has shaped in society and the economy, the speed of future vaccines is going to be a key advantage.
It is demoralizing to think what would be happening now if the vaccine against coronavirus took 10 years.
As
Nature
recalls
, pneumonia, malaria and tuberculosis kill millions of people every year.
The 2020 crisis has shown to what extent planetary emergencies and the injection of resources can accelerate scientific solutions.
In the developing world these other emergencies are common, but they do not attract resources.
But today's speed has its roots in the past, as we saw at the beginning.
They are largely due to years and decades of research into other more or less related viruses, and in particular other coronaviruses, such as SARS and MERS.
Research builds on previous knowledge, or "on the shoulders of giants," in Newton's expression.
It remains true, however, that the enormity of funds dedicated to covid has allowed a new style of doing clinical trials, in which the three phases, so far consecutive, overlap.
Despite everything, this reveals that the advances we have learned in this pandemic are not immediately exportable to other health problems.
The pasta will be missing.
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A marvel of evolution
Any vaccine is ultimately a trick to trick or persuade our immune system to work for us.
When talking about brilliant inventions, such as mRNA vaccines, it must be recognized that they pale in the face of the creative power of biological evolution.
The immune system has sensors that allow it to detect a protein or an infectious agent of any kind, and that implies that it knows how to distinguish between these foreign invaders and the hundreds of thousands of molecules of the human body.
When that distinction is blurred, one of the 50 autoimmune diseases described, such as arthritis, lupus and various kidney ailments, occurs.
But it usually works very well.
The most extraordinary thing about this prodigy of evolution is its ability to learn.
When a cell (lymphocyte, a white blood cell) produces an antibody that recognizes the foreign agent, the stem cells of that lymphocyte are stimulated to proliferate.
And also to try variations on the original idea, playing with the antibody gene itself, mutating its contact areas with the virus, shuffling its genetic modules.
And most amazing of all: the immune system comes from an ancient virus.