How COVID-19 ends
From finding a vaccine to reaching herd immunity naturally, this is what the science says about how we return to normal
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From finding a vaccine to reaching herd immunity naturally, this is what the science says about how we return to normal
From finding a vaccine to reaching herd immunity naturally, this is what the science says about how we return to normal
From finding a vaccine to reaching herd immunity naturally, this is what the science says about how we return to normal
Not since the Second World War has so much of the world been devoted to a singular goal: Taming COVID-19 and restoring the world and its economy to some semblance of normalcy. In Canada alone, there are 244 publicly funded research groups working at universities, private companies, and non-profits across the country that have been mobilized in the fight against COVID-19.
Eight of those groups are in Victoria, and one of them comprises the author of this piece. Below, researcher Harley Gordon lays out the best available science on how we will return to a world of travel, music festivals and handshakes.
Vaccines are the ideal solution to infectious disease. Smallpox, polio, measles and many of history’s other big killers are extinct or in retreat entirely due to vaccines.
A vaccine is something you receive that tricks your body into thinking it is under assault by a specific disease (Covid, chicken pox, measles etc.). Then your immune system gets to work and creates antibodies to fight that disease. These disease-fighting antibodies circulate through your blood long after you’ve received the vaccine, and thus provide long-lasting immunity. Early data on COVID-19 shows that survivors of the disease are incredibly unlikely to catch it a second time, and a vaccine would effectively give people that same immunity without first having had to battle the full-blown disease itself.
However, not all diseases are equally amenable to vaccines. Take a look at influenza; the flu shot is only partially effective (20% - 60%), and since influenza mutates so quickly from year to year we have to develop a new vaccine every year.
COVID-19, of course, is a coronavirus; the same type of virus as those that cause a common cold. While the common cold is nowhere close to being cured, a different coronavirus, SARS, had a vaccine undergo human trials in 2004, but by then the SARS outbreak was over and there was no need to continue development. So, unfortunately, at this point there has never actually been a market-ready vaccine for a coronavirus.
Herd immunity refers to the fact that if enough people are immune, through recovery or vaccination, then the virus will no longer spread as there are not enough susceptible hosts.
Some diseases like measles that are particularly contagious require a population that is 95% immune, but COVID-19 isn’t as infectious as that. In fact, recent research suggests that we can achieve herd immunity with rates as low as 43%.
Early COVID-19 research from around the world is uniformly showing that the disease infects exponentially more people than are reflected in the usual case counts; there are likely people reading this right now who have already contracted and recovered from COVID-19 without even knowing it.
This, combined with growing knowledge that the virus may have been spreading around the world as early as December, points to the fact that if more people have survived COVID-19 than previously suspected, hard-hit areas such as New York and Montreal may be approaching herd immunity.
Vaccine, and drug development follow a strict process prior to being approved for sale. Before anything is ever given to people the candidate vaccine is considered “preclinical”, this is a stage of testing on animals and strictly in the laboratory. If the vaccine works in the lab, it enters phase I clinical trials, where a very small dose of the potential vaccine is given to a few people, After a successful phase I is phase II, historically the least successful phase, where several hundred people are given the vaccine. Then, finally, there is phase III which involves widespread inoculation of at least several thousand people. If successful there it can then finally move on to receive regulatory approval and distribution.
Currently there are 170 COVID-19 vaccines under development. Many are preclinical, others have passed phase I trials, and some have even passed phase II. There are now four vaccines just beginning to enter phase III trials, one example being from the biotech company Sinovac that will begin inoculating 9,000 healthcare workers in Brazil this month. Phase III trials generally have the highest success rate so there is a reasonable chance that at least one of these four vaccines will be effective and hopefully distribution can begin in a timeline of months, not years.
Vaccines themselves are difficult to produce; on average it takes 10 years to develop a vaccine, and the success rate is only 6%. However, most diseases don’t see anything close to the same kind of massive worldwide effort now being directed towards a COVID-19 vaccine.
The most optimistic experts say that a vaccine will be ready for commercial production and distribution by the end of the year. In fact, some companies are thinking ahead and stockpiling potential vaccines in the hope that their clinical trials continue to go well, so they will be able to ship (and sell) their product the moment they receive regulatory approval. Vaccine availability by the end of 2020 is about as optimistic as it gets, but a more measured approach suggests that by mid-2021 there will be an effective and available vaccine.
Even if COVID-19 can’t be eradicated, there are plenty of ways to help fewer people die from it. The classic example is HIV; there’s no cure, but a cocktail of treatments first developed in Vancouver means the virus is no longer an immediate death sentence.
Researchers have been extensively screening available drugs for any effects on COVID-19 survival. Worldwide, there are at least 260 different treatments under study. There have been some successes so far, one such example is the widely available drug Dexamethasone (an anti-inflammatory steroid), in which preliminary results demonstrate the capacity to reduce deaths by a third. There is currently no authorized drug for treatment of COVID-19 in Canada, although there are 47 ongoing clinical trials. The drug Remdesivir has also been shown to be effective, but the US has secured the global supply of it for the next few months.
These large scale clinical trials are absolutely necessary before drugs can be recommended to treat a disease. The antimalarial drug Hydoxyquinoline, which was touted by US President Donald Trump as a cure after showing a small amount of success in a few patients has since been debunked. Large scale testing showed that the drug actually increased the chances of patients dying. When drug approvals can affect the survival rates for millions of COVID-19 patients worldwide, it pays to be sure.
One of the greatest triumphs thus far in fighting COVID-19 has been improved testing capacity. At the beginning of lockdown measures, there was only one known way to test for the disease. There are now 26 approved COVID-19 tests in Canada with 48 more undergoing approval review now.
Some of these tests are “serological” or antibody tests which can determine if someone has been exposed to COVID-19 in the past, and is thus already immune.
These tests are being used to screen Canadians and Health Canada plans to release results of these screenings mid-July, when we will then get a better idea of how widespread the disease is in Canada. There are also “point-of-care” testing devices becoming available, these are tests that can be administered in a doctors office and don’t require a laboratory. Rapidly available tests are critical in quick contact tracing and preventing spread. If you know within six hours of waking up with a cough whether or not you have COVID-19, you’ll probably make better decisions in regard to your own self quarantine.
With over 12 million confirmed cases worldwide the chances that COVID-19 will ever be “put back in the bottle” are very slim. If we can get a vaccine that is able to provide us with long term immunity, and we can get that vaccine distributed on a global scale, there is a chance that the disease will go the way of polio and smallpox, but just as with those two diseases that won’t happen without a coordinated, years-long public health effort.
Thankfully for us Canadians, being in a wealthy country means that when there is an available vaccine we should all have a good chance of receiving it. And while there is a vocal minority of Canadians opposed to vaccines of any kind, Canada generally has high vaccination rates, as 91% of Canadians consider vaccines to be important for their health.
In a recent poll of 100 adults by Research Co., 75% of Candians said they would likely take a COVID-19 vaccine. There were sizable differences between the provinces (81% in BC but only 68% in Alberta) but either scenario would push the population well past the aforementioned 40% needed for herd immunity. Once we reach that threshold of herd immunity the spread of COVID-19 in our cities and care homes will be limited without the need for social distancing.