The universal vaccine would kill all viruses of the same type, not just Covid.
Most of these only infect birds or animals, but 7 have (for now) passed to humans. 4 of them carry only mild symptoms. 3 cause serious diseases (SARS, MERS and COVID-19). Many virologists think it's only a matter of time before the next deadly threat emerges.
"It has already happened three times", says Daniel Hoft, virologist at Saint Louis University. "It is very likely that it will happen again."
The importance of a universal vaccine
Vaccines are one of the best ways to stop the spread of an infectious disease, and the world approved its first COVID-19 vaccines less than a year after the pandemic began: a huge achievement, as the process usually takes a decade.
Despite the rapidity, the virus has already claimed millions of deaths, and is now developing new dangerous variants. A better approach, according to the infectious disease expert Kayvon Modjarrad, is to prepare a vaccine even before a pandemic begins. A universal vaccine.
We were fast. But we will be even faster when we have a universal vaccine available from the first moment a pandemic breaks out.Kayvon Modjarrad
We cannot develop a vaccine for a coronavirus that does not yet exist. However, we may be able to create a universal vaccine against all coronaviruses.
It is a worldwide hunt
Several research groups are now working on a universal vaccine, and one of them he just announced promising progress.
The mechanism of operation of a universal vaccine
When the immune system first encounters a pathogen, it creates proteins called antibodies. If it infects the body again, those antibodies can then quickly identify and disable the invader, as well as trigger the wider immune system.
Vaccines protect against disease by producing these antibodies before an infection. Most COVID-19 vaccines do this by introducing the body to the so-called "Spike protein," a part of the coronavirus that activates antibodies.
All coronaviruses have their own spike protein (it is the one that creates the crown-like appearance, hence their name). It's their latch: they use this protein to attach and infect cells.
How the creation of the universal vaccine against coronaviruses is progressing
To create a universal coronavirus vaccine, researchers from the Caltech they started with a "frame" called a "mosaic nanoparticle". A sort of grid made up of 60 identical proteins.
They then designed fragments of spike proteins from eight coronaviruses (the Sars-CoV-2 and the seven that for now only infect animals, but are considered a threat to humans). The end result was a vaccine with many different coronavirus spike protein fragments.
When the universal coronavirus vaccine was injected into mice, triggered the production of antibodies that also reacted to the eight coronaviruses and four others. Three of these were viruses that infect animals and one was a coronavirus that infects humans: SARS-CoV.
This suggests that the vaccine taught the immune system to recognize the common characteristics of coronaviruses.
The universal vaccine, a "school of viruses"
"This study shows that it was possible to increase several neutralizing antibody responses, even against coronavirus strains that were not represented on the injected nanoparticle," he says in a Press release the researcher Pamela Björkman.
This mouse test is a good first step towards developing a universal coronavirus vaccine, but there are many more advances on the way.
First of all, we need to understand if the CalTech universal vaccine can actually prevent infections or symptoms in animals. If so, human testing will follow.
If all goes our way, the next time a dangerous coronavirus hits humans, we may already be immune to it.
Preventing a pandemic is much better than defeating it.
“None of us want to repeat all of this,” he says Matthew Memoli, virologist of the NIAID. "And we don't want our children to experience it again, nor our grandchildren, nor our descendants in 100 years."