Don’t drink disinfectant. Don’t inject it. Don’t inhale it. Disinfectant is more toxic to you than to the coronavirus, so it is not an effective way to avoid COVID-19, the disease caused by the coronavirus.
Unlike cancer treatment, in which the disease is literally caused by your own cells - so in trying to kill those cells, patients are themselves brought to the edge of death - treatments for viral diseases are generally not so dangerous.
The best known are vaccines.
In my last column, I discussed the different ways we can detect the SARS-CoV-2 coronavirus. Today, I review some of the ways to kill it. Well, not kill it. Remember? It’s not actually alive. So I guess we are inactivating or neutralizing it. Anything to stop it from reproducing.
Five hundred years ago, your ancestors believed many interesting things: that life could arise spontaneously from rubbish; that misfortune was caused by witches casting spells; that what happens to you today is significantly influenced by where the planets happened to be in their orbits around the sun on the day you were born.
Ever since the great thinkers of the Enlightenment showed us that the world makes more sense if we look for evidence in nature, however, we have gained greater understanding and control over life’s misfortunes. There are few more powerful examples of this than vaccines, which have essentially banished from humanity the viruses that used to kill roughly one in three children.
Think about that. One in three children.
There are a number of ways to make a vaccine, but the basic idea is to present something to your immune system to get it primed so that if the real virus shows up it is ready to attack it. Kind of like a practice run. What would most look like a virus to your immune system? Well, one thing is the virus itself - a so-called live virus vaccine - but obviously that strategy has risks.
One common technique for making a vaccine is to produce lots of virus and then inactivate it somehow. In other words, treat it with heat or chemicals or radiation so that it still looks like a virus to your immune system, but is incapable of reproducing in your body. If the virus can still reproduce a little bit then, it is an attenuated live virus vaccine, like the measles vaccine. If it can’t reproduce at all it is called inactivated, like the newer polio vaccine.
But it is expensive and slow to grow viruses in large quantities.
Modern molecular biology provides interesting alternatives. In my lab, we sometimes need to make a particular protein so we can study what it does. Usually, we put the DNA that encodes that protein (i.e. that has the instructions for a cell to make it) into bacteria. The bacteria make the protein, and we grind them up and take the protein out.
Now imagine that instead of using intact viruses as a vaccine, we just used the proteins on the outside of the virus. That’s the only part our immune system recognizes anyway, since the rest is buried inside the virus where antibodies and immune cells can’t reach it.
Such viral proteins can be produced in just the same way that we make proteins in my lab: the DNA instructions for making them can be put into bacteria, the proteins extracted, and finally cleaned up and used as a vaccine. But making proteins for use as vaccines is complicated and expensive.
Now there is a more clever way.
Recall that the virus only needs to get its RNA genome into your cells in order to get your cells to make viral proteins. Your body recognizes those proteins as foreign, and mounts an immune response. Thus, instead of using viral proteins as the vaccine, we could use viral RNA.
It turns out that making RNA in large quantities is cheaper and easier than making proteins. This is the basis of the vaccine that Moderna, in Cambridge, Mass., is developing. They are one of the first companies to move into clinical trials of a candidate vaccine against SARS-CoV-2, because they don’t have to produce viruses and inactivate them. They don’t even have to make viral proteins. They just have to make the RNA message for one of those proteins.
We don’t know yet whether it will work, but it is certainly a quick way to a candidate vaccine.
Vaccines rely on stimulating your immune system so that it is prepared when a live virus comes along. Another way to fight viruses is with antiviral compounds, such as the so-called anti-retrovirals used to combat HIV.
These are small molecules - in other words, chemicals - unlike proteins and RNA and DNA, which are enormous molecules. One big advantage of antiviral compounds is that they can get right into your cells and stop the virus before it kills them.
The problem is that we - mostly - don’t have any way to design such compounds. Most of them are found by brute force, literally testing millions of different chemicals to see whether any of them stop a virus from reproducing. This can take years.
In contrast, Moderna designed and produced its RNA vaccine in weeks.
So what is the end game with COVID-19?
With PCR testing and contact tracing, we can lift many social distancing restrictions, but may have to reimpose them when there is another outbreak. With an antibody test, we can find out who already had COVID-19 and is therefore (hopefully) immune. Those with immunity can safely go back to their regular lives if testing and contact tracing ensures that they aren’t exposed to viruses that they could pass on with their hands.
And with a vaccine, if it works, we can protect everyone from the risk of getting COVID-19 in the future.
Fingers crossed that one of these strategies comes to fruition soon, because I’m ready to be done with being on lockdown.
Stay safe.
Stay healthy.
-Stephen Rader is a professor of biochemistry at the University of Northern British Columbia. His laboratory studies how RNA is processed by our cells. He is the founder of the Western Canada RNA Conference.
