WHY THIS MATTERS IN BRIEF
Today there are no vaccines for Covid-19 and complete vaccines will take at least 12 to 18 months to materialise, so scientists are turning to alternative approaches.
As the coronavirus pandemic, COVID-19, continues to rage around the world, in spite of incredibly valiant attempts to stem its spread, the big question on everyone’s lips is “when will a vaccine appear?” And the general consensus is that it’ll appear in between 12 to 18 months time which, frankly, just like the vaccines for previous epidemics like Ebola, whose “100% effective” vaccine emerged a year after the epidemic, MERS, and SARS, is too late for most people.
Consequently there are now many initiatives underway to try to bring this time down, with the use of AI’s and supercomputers to crunch through viable vaccine compounds, the development of contagious vaccines, and with bleeding edge research organisations such as DARPA who are trying to develop a COVID-19 therapeutic shield to tide us all over until a vaccine appears. And now there’s another longshot being developed.
All new drugs that come into development are long shots, but some are longer than others. For example, the vaccines most imminently starting trials for COVID-19 range from the promising but speculative to the highly promising but ethically fraught.
On Monday, Kaiser Permanente began soliciting volunteers to be injected with a mystery substance that will, if it works and does not cause unintended harm, release us all from quarantine purgatory when it becomes widely available in a reported 12 to 18 months. The trial is a partnership between Moderna, a Boston biotech company, and the National Institutes of Health, and it would not be an exaggeration to say that no pharmaceutical trial’s results have ever been awaited as breathlessly as this one’s.
What makes this research a long shot is that the type of vaccine it is pursuing has never been approved by regulators, and like all experimental drugs, it could fail spectacularly in many different ways.
Nearly every vaccine currently approved by the Food and Drug Administration introduces foreign proteins into a healthy but non-immune individual. The body’s immune system finds those proteins, which are often part of a pathogen, the measles virus, say, and then quickly learns to recognise them. When the actual virus arrives, your immune system has already been introduced to the offending proteins and knows how to annihilate any living thing that bears them. The measles never stands a chance.
Moderna works in the field of RNA vaccines – injecting not proteins but the molecules of nucleic acid that encode the instructions for building the proteins. Your cells use RNA to instruct their builders to make proteins all the time; the RNA is like the blueprints or schematics that tell the workers on the factory floor what to build. An RNA vaccine injects instructions to your cells, and hopes that your cells receive these instructions and follow them, and build the proteins that will teach your immune system to fight a virus. It is a bit like wadding up plans for a Cessna, throwing them through the ventilation shaft of a Ford factory, and hoping that someone inside finds them, and that the factory starts rolling airplanes out its doors instead of pickups.
Despite successes in animals, this strategy has never yielded a vaccine approved for human use. Moderna is a leader in this approach, and you can be sure the scientists there have considered all the ways to make it more likely to work. They throw the plans down the shaft nearest the factory manager’s office; they attach official-looking paperwork and bribes. But their approach is ambitious. If it works in humans, it will represent a huge advance in immunology and clinical medicine.
The RNA vaccine approach has one great advantage – speed. Scientists merely need to know the virus’s genetic sequence, and they can synthesise and scale up production of an RNA vaccine in a matter of weeks. RNA is fragile. In a lab, you have to shield your face to work with it, not because it is dangerous but because you are dangerous to it. Even a gust of saliva is likely to contain enzymes that would rip RNA apart, rendering it worthless. As long as it’s formulated properly, RNA is considered nearly harmless to inject into humans, and a Phase 1 trial like this is easy to begin. But success is hardly assured, however at least wenknow that the RNA won’t hurt the people in the trial who are being paid $1,100 to have it injected into them. It is a clever approach, but don’t eat through your boxes of stockpiled wholesale ramen too quickly, because unfortunately no one can or should guarantee that an RNA vaccine will stop the pandemic anytime soon.
There is another option, less ambitious but more likely to work, and with a calendar for deployment perhaps as short as three to four weeks, with results four weeks later. We’ll call it the human-blood-bag approach.
If you survive COVID-19, and to date 86,025 people have done so, it’s because your body wised up to the attack and learned to fight it off then congratulations you now produce antibodies to the coronavirus. And if you are willing to share them, you are now someone’s new best friend.
The process is simple. Surrender some of your blood, and a lab will filter out the cells and keep only the amber-coloured serum, with the antibodies to the virus still in there and active. This serum, further refined, is called “hyperimmune globulin.” All that remains is to infuse the serum into a healthy person or, in much greater quantities, into a sick one. The antibodies won’t last forever, but they could last weeks or months, and either help a sick recipient heal or keep a healthy recipient from getting the virus at all.
The approach does carry risks. Antibodies to a virus can make a viral infection worse in some cases, such as with dengue fever. We don’t know if COVID-19 will react that way even though most viruses do not. Despite this, Casadevall says he has already had volunteers who wish to donate their antibodies or receive the serum from others.
“This is real,” he says. “In eight weeks, we may have something that’s useful.”