Taken from Medium.com
I’m an expert on online disinformation, misinformation, and mathematics relevant to disease transmission. Recently I’ve been answering a lot of common questions about Covid-19 on social media, trying to dispel misconceptions and falsehoods. I’ve compiled a list of the most common responses, with the hope that this makes this information more easily accessible to others. Note: I am not a public health or medical professional, however, I have taken extra care to square all my responses here with official guidance and medical advice.
Q: Why are people freaking out about this more than flu?
A: Each person infected with seasonal influenza may infect approximately 1.3 other people. For SARS-CoV-2 (the virus that causes Covid-19), it is estimated to infect about three times as many people (estimated at 2 to 4). This number is called the reproductive factor, or “R0,” and you may see it referred to that way. This will lead to many, many more cases very quickly, and may overwhelm an already burdened medical system.
Q: Why should I even care if I get it? It doesn’t seem that lethal.
A: It’s true that for healthy people under age 50, it’s not especially lethal — the mortality rate is quite low, but still up to 20 times higher than flu. But it becomes more lethal for older patients. The following chart gives good estimates for mortality rate by age bracket compared to flu. The WHO estimates an average mortality rate of 3.4%, which is around 100 times higher than flu, but do note that average is across age brackets. And while you may not die, you may give it to others, which will overwhelm our healthcare system.
Q: If I’m likely to get it, why not just get on with it? I don’t want to change my routines just for this, and it doesn’t seem that dangerous.
A: Don’t be the person that takes up medical resources that someone else needs more than you do. This is our ethical North Star with this disease. The goal should be to minimize spread so that as health resources (from diagnostics, to treatments, to ventilators and oxygen concentrators) are needed, they are available to people who need them most. Share this graphic on people’s social media pages; it explains exactly why this is important. See this story for how the health care system may be overwhelmed. If we can slow down the spread, we have more time to react and make preparations. A slower spread will save many lives, because an overwhelmed healthcare system will not be able to provide care to all who need it. Health experts call this “flattening the curve,” and it’s perhaps our best and only strategy for mitigating this situation.
Q: Aren’t other diseases like SARS, MERS, or H1N1 more lethal? Why freak out about this one?
A: The issue isn’t the lethality as much as the overall impact of the outbreak. While these other diseases may be more lethal, the combination of reproductive factor (R0), receptivity in the population (susceptibility), and immunity may make them much more manageable. SARS-CoV-2 (the virus that causes Covid-19) is totally novel to the population, so no one is immune. Each year, people are already immune to the flu because of exposure to prior variants, or because of annual vaccination. There is no vaccine available for SARS-CoV-2 yet. We should expect it will be at least Q1 2021 before a tested vaccine is widely available. In the meantime, everyone is likely vulnerable, so we should expect that an extremely large number of people will be infected. (See this Atlantic article.)
Q: How many people will be infected? Is this really a big deal?
A: Yes, it is a really big deal. Because there are no real barriers to spread and the reproductive factor (R0) is so high, it is possible and indeed likely that 20–70% (source) of the global population will be infected. That is 1.5 billion to 5 billion people. With an estimated mortality rate of about 2% (source), that is 30 to 100 million deaths, globally. In the US we might expect that 66 million to 231 million people may be infected, with as many as 1.2 to 4.6 million dead, possibly more. That may well also be an overestimate; we don’t know a “true” mortality rate yet, but the WHO estimates it may be as high as 3.4%. But the mortality rate isn’t as important as the fact that the medical system will be overwhelmed, because this will all happen really fast. And yes, many people will die. We just don’t know how many yet.