20 Facts About COVID-19
Some mythbusting for the end of the year, with references

In the last 12 months, fact checking has gone from a fun pastime where you get to make fun of Big Walnut to something of a life-and-death scenario where the myths that are promulgating online can have serious consequences for people’s longevity. Instead of impacting which berry you favor at the supermarket checkout, the scientific myths of 2020 might define how your government chooses to respond to a global pandemic.
It’s a bit less fun than it was last year to check facts, is what I’m saying.

And somehow, some of the biggest myths about COVID-19 are still spreading. Given the global situation, I thought I’d round off the year by looking at some facts that are well-demonstrated about COVID-19, with references.
Enjoy.
FACT 1: COVID-19 IFR IS HIGH
The death rate of COVID-19 varies substantially by age. I and my colleagues demonstrated this in a paper aggregating antibody studies from across the world. We also showed that, even for relatively young people, COVID-19 is pretty dangerous — at the age of 35, about 1 in 2,700 people who get COVID-19 will die of the disease.
FACT 2: COVID-19 IS MORE LETHAL THAN INFLUENZA
Another fact that we have known for some time is that COVID-19 is far more dangerous than influenza. For younger people, particularly age 5–20, the two diseases are comparable (we don’t have good data on <5yo for COVID-19 so it’s hard to compare), but for anyone older than this COVID-19 is far worse.
FACT 3: PCR TESTING FOR COVID-19 HAS A VERY LOW RATE OF FALSE POSITIVES
Yes, it’s true, false positives are incredibly rare when it comes to PCR testing for COVID-19. They definitely happen, but unless you have fewer than 1 case per million people in the country it’s almost certain that true positives are vastly more common than false ones.
For some context, the Australian state of NSW has an outbreak happening right now. We ran 138,966 tests and found 94 positives from 16/12–23/12. If every one of those positives was a false positive (which is...unlikely), the false positive rate would be 0.068%, or 1 per 1,500 tests run.
Yes, the ‘casedemic’ is a myth. Sorry.
FACT 4: MOST DEATHS ATTRIBUTED TO COVID-19 WERE CAUSED BY COVID-19 (AT LEAST IN THE U.S. AND MOST DEVELOPED NATIONS)
This is something of a complex fact, because it is important to say that every country is different, and so it’s entirely possible that in some places COVID-19 deaths are wildly misclassified.
That being said, there is abundant evidence from the U.S. and elsewhere in the developed world that this is largely a non-issue. If anything, the opposite — i.e. not counting all deaths caused by COVID-19 as COVID-19 deaths — is a bigger problem.
FACT 5: COVID-19 IS A REAL DISEASE CAUSED BY SARS-COV-2
Weird that this actually needs to be said, but there are conspiracists out there who still spread the lie that COVID-19 is a hoax. It isn’t.
FACT 6: EVIDENCE PUBLISHED THUS FAR SHOWS NO INCREASE IN SUICIDES ASSOCIATED WITH LOCKDOWNS
This is another complex point, but basically people were sure that lockdowns would cause enormous surges in the suicide rate. Thus far, from evidence around the world, we have not seen such increases. There are definitely issues with mental health associated with lockdowns, and it’s likely that the pandemic itself will have an impact on suicides, but so far the published data do not show increases in suicide numbers associated with lockdowns.

FACT 7: THE IMPACT OF GOVERNMENT RESTRICTIONS ON COVID-19 IS COMPLEX
This should come as no surprise to anyone, but the impact of implementing restrictions (such as lockdowns) to prevent the spread of COVID-19 is not a simple calculation. As the International Monetary Fund has shown, in some cases there may be a net benefit from lockdowns. In some cases there may be a net detriment. It is complex, and very hard to pin down to a definite good/bad, no matter how much people may want it to be simple.
FACT 8: COVID-19 CAN BE SPREAD ASYMPTOMATICALLY
Of those who are infected with SARS-CoV-2, best evidence indicates that about 20% will be fully asymptomatic during their entire disease. These people can probably spread the virus, but to what extent we aren’t entirely sure. However, there is also evidence that the peak of infectiousness (when someone is most likely to pass on the disease) is right around the time that they start experiencing symptoms. What this means is that someone who is currently asymptomatic may still be very infectious, especially if they go on to develop symptoms later. This is why isolating positive cases of COVID-19 is so important!

FACT 9: PRE-EXISTING IMMUNITY BECAUSE OF T-CELLS IS NOT A THING
A very popular myth that consistently gets brought up by denialists is that we are all immune to COVID-19 already because some people’s t-cells react to the disease without them being infected. Rather than explain why this is flawed, I’d recommend you read this thread by Professor Crotty, the immunologist who made the initial findings about t-cells that got everyone excited in the first place.
FACT 10: MOST PLACES IN THE WORLD ARE STILL WELL BELOW HERD IMMUNITY THRESHOLDS
This fact is, sadly, becoming somewhat less true as time goes on, but even with the massive outbreaks in the United States and Europe, the number of infections is still well below the 60–70% — or even a lower threshold of 40–50% — that we would need for the pandemic to substantially falter. While estimates vary, it is likely that even in the US less than 20% of the population had been infected by December despite record hospitalization and death numbers.
FACT 11: COVID-19 IS PROBABLY LESS LETHAL NOW THAN IN MARCH 2020 BUT IT IS VERY HARD TO KNOW HOW MUCH
Is COVID-19 less likely to kill you now than when the disease first emerged? Almost certainly. We have better treatments, better understanding of the disease, a vaccine, etc. How much less lethal is it? That is an incredibly hard question to answer.
FACT 12: THE CYCLE THRESHOLD OF PCR TESTS IS LARGELY NOT AN ISSUE FOR FALSE POSITIVES
Earlier this year, everyone became overnight epidemiologists. With the advent of the latest conspiracy theory — that all COVID-19 PCR positives are false positives — everyone became overnight virologists instead. Here is an excellent piece by Professor Ian Mackay of the University of Queensland on why you shouldn’t worry about cycle threshold (CT) values and PCR tests for COVID-19:
FACT 13: YOU CANNOT COMPARE GOVERNMENT ACTION ON COVID-19 TO “LIFE AS USUAL”
This is something of an obvious fact, but again a point that is often made by denialists. If we took no action on COVID-19, apparently, life would be back to normal. This is obviously untrue, because having an out-of-control epidemic raging through your population and filling up ICU beds also has consequences for the economy, as the IMF report referenced above shows.
FACT 14: LOCKDOWNS REDUCE CASE NUMBERS. GOVERNMENT ACTION CAN KEEP CASE NUMBERS LOW LONG-TERM
One of the startling things about the global pandemic, as an Australian, has been watching people across the world declare that it is totally impossible to control the virus and we should all stop trying. There are numerous examples from our region of globe — Vietnam, Taiwan, Thailand — as well as Australia itself where the wave of the pandemic has been reduced to a slow trickle. Last week the Australian state of New South Wales was the subject of enormous national outcry because we had a day with 30 new cases, although this outbreak appears (fingers crossed) to now have been controlled.
Whether this means that lockdowns/restrictions “work” or not depends entirely on your definition of “work”, but it is absolutely clear that it is possible to control the virus even long-term through such restrictions.

FACT 15: COVID-19 WAS THE LEADING CAUSE OF DEATH IN THE UNITED STATES TOWARDS THE END OF 2020
A new scientific paper was recently published looking at public statistics on mortality in the U.S. during 2020. The daily deaths attributable to COVID-19 were the highest of any cause for several months of the year, and overall it was the third leading cause of death behind heart attacks and cancer. Moreover, even though COVID-19 was only officially the cause of death for 40% of the excess deaths in young people during 2020, it is likely that this is due to undercounting and that COVID-19 was the primary cause of excess fatalities even in younger age groups.
FACT 16: THE LONG-TERM CHRONIC IMPACT OF COVID-19 IS UNKNOWN, BUT NON-TRIVIAL
It is, at this moment, very hard to put a number on the total long-term impact that COVID-19 has on people who survive the disease. That being said, there are indications that the number of people impacted in this way — by LongCOVID and other issues — is non-trivial, and may represent a substantial portion of the people that recover from COVID-19.
FACT 17: NEW ZEALAND RECORDED FEWER ALL-CAUSE DEATHS IN 2020 THAN IN PREVIOUS YEARS
Another point against the “lockdowns kill millions” argument is that New Zealand, with arguably the toughest COVID-19 restrictions in the world, recorded fewer all-cause — or “excess” — deaths in 2020 than ever before. Indeed, during the New Zealand lockdown there appears to have been a substantial reduction in the all-cause death rate, which would be impossible if the lockdown was causing untold tragedy.
FACT 18: THE AVERAGE LIFE EXPECTANCY FOR AN 80 YEAR OLD IS ~9 YEARS
Because people still go on about the absolutely ridiculous idea that old people are all on death’s door, here are the facts from the United Kingdom. At age 80 you would expect to live an average of another 9 years (8 for men, 10 for women). If someone dies at the age of 80 due to COVID-19, it has cut their life short by almost a decade, on average.
FACT 19: COVID-19 REINFECTIONS OCCUR
This is, again, not a contentious point. We always suspected that reinfections would happen — they do for all other coronaviruses — the question is how often and how long on average until it starts to happen. Thankfully, every indication at this point is that reinfections are relatively rare, which is great news for vaccines which will probably provide quite long-lasting protection.
FACT 20: THERE ARE STILL MANY UNKNOWNS

Ultimately, this article is not about giving you absolute answers to everything, because that’s impossible. People who express total certainty tend to be wrong a lot, because we really don’t know that much about COVID-19 even now. The science done this year has been absolutely incredible, true, but despite this there are questions about everything from school transmission to the precise infection-fatality rate for each place in the world. The reality is that we may never have perfect answers to all questions, but we do know some things and I’ve tried to sum them up here for you.
There are many trade-offs when it comes to COVID-19. It’s important to recognize that none of these facts makes lockdowns a given, nor even supports government restrictions per se. In some cases, it’s almost certain that a lockdown will be a terrible path to take.
The point here is that every way forward has consequences, some good and some bad. It may not be easy to make decisions about COVID-19, but if we do not at least use facts to inform our choices we will end up much worse off overall.