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.
In this piece, I’ve compiled a list of the most commonly asked questions and responses, with the hope of making this information more accessible. Please 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.
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 two to four). This number is called the reproductive factor — or R0, sometimes pronounced “R-naught” — and you may see it referred to that way. A higher reproductive factor means COVID-19 will lead to many, many more cases very quickly and may overwhelm an already burdened medical system.
Even if you are not at high risk yourself, we still all have a public health obligation to take interventions that will prevent its spread.
It’s true that for healthy people under age 50, it’s not especially lethal — the mortality rate is quite low, though still up to 20 times higher than flu. But it becomes more lethal for older patients. The chart below 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. Current evidence suggests that the fatality rate from COVID-19 ranges from 9% to 19% for older individuals, as well as for people with conditions such as cardiovascular disease, diabetes, and cancer and those who are immunocompromised. Even if you are not at high risk yourself, we still all have a public health obligation to take interventions that will prevent spread that could overwhelm the health care system, as is happening now in Italy.
Don’t be the person who 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 (diagnostics, treatments, ventilators, oxygen concentrators, etc.) are needed, they are available to the people who need them most. The graphic below explains exactly why this is important. If we can slow down the spread, we have more time to react and make necessary preparations. A slower spread will save many lives, because an overwhelmed health care system will not be able to provide care to all who need it. Health care experts call this “flattening the curve,” and it’s perhaps our best and only strategy for mitigating this situation.
The issue isn’t the lethality of COVID-19 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 new 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 yet for SARS-CoV-2. 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.
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% to 70% of the global population will be infected. That is 1.5 billion to 5 billion people. With an estimated mortality rate of about 2%, that is 30 million to 100 million deaths globally.
In the United States, we might expect 66 million to 231 million people will be infected, with as many as 1.2 million 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. But we can limit the total number of people infected if we take serious containment measures early on. That will save lives.
We don’t know, but the rate of doubling of known cases seems to be every few days — with the caveat that reported numbers are likely undercounting actual cases. This means that without major interventions, this infection will reach much of the world’s population in a matter of weeks or a few months. This could be as many as 1.5 billion to 5 billion people, as mentioned above.
We don’t know yet. There is some reason to think this disease may slow in warmer temperatures. However, it has a high reproductive factor (R0), a high prodromal (asymptomatic) period of about 14 days, and it’s not the same as flu. Warmer countries like Singapore have cases right now. We are watching developments in other warm countries that also have cases. And people may be carriers without showing symptoms. While transmission via surfaces (where it can survive for several days) may diminish with temperature, we don’t know how or if host-to-host transmission may be affected. So it may persist into summer despite warmer temperatures, while also shifting its prevalence into the Southern Hemisphere, where it is cooler. In fall, it may resume where it left off and continue infecting people, if there are susceptible people left to infect. Or it may reinfect people, if somehow reinfection is possible or if a mutation appears. Do not expect this to be over by September.
Vaccines are under development, but getting a workable, tested vaccine out to market will take time. While some teams claim to have vaccines now, it will take some time to refine, test, manufacture, market, and deliver these solutions. Producing enough vaccines for billions of people will not be a small task and will take time, capital, and coordination with governments. Estimates suggest the soonest any vaccines will be available is Q1 2021.
Your best defense is frequent hand-washing with soap and water and not touching your face, nose, eyes, and other mucous organs. While hand sanitizers with high levels of alcohol work, soap and water are extremely effective and should be your first choice. Soap molecules have a fatty end that attaches to and penetrates the lipid shell of the virus and a hydrophilic (water-loving) end that water attaches to and rinses away the soap with the virus. Hand sanitizer may render the virus impotent, but it leaves the virus on your hands. Wash hands frequently. Keep your distance from other people, and try to avoid unnecessary travel and social gatherings. Here are some CDC recommendations. If you’re somewhere without ready access to soap and water, go to someplace where you do and stay there.
A slower spread will save many lives, because an overwhelmed health care system will not be able to provide care to all who need it.
Both the Chinese and South Korean governments took extremely decisive actions to minimize the spread of this disease. The Chinese government is an authoritarian regime that could unilaterally impose and enforce a lockdown of several weeks. Governments in the United States and Europe will have a harder time doing this, but we will likely see increasing momentum around school closings, event cancellations, movement restrictions, and other social distancing measures. Italy enacted a lockdown for a month. Nicholas Christakis, an expert on the 1918 flu, suggests that the sooner we do this, the more lives will be spared.
We don’t know. Expect March, April, May, and June 2020 to be heavily disrupted. Beyond that, we may see a reprieve in parts of the world with warmer weather (see above). But given that it will take until 2021 to have a workable vaccine at scale, we should expect at least some disruptions until around that time. We should be able to make better estimations with each passing month. But don’t expect that things will get back to normal on any predictable timeline. We could also see another resurgence in the fall.
Yes! Panic, worry, and fear are totally unhelpful. Instead, we should be realistic and prepared, and we should have a rational framework for thinking about our response to this, with full transparency from government agencies. While we may be falling short of this standard at the moment, we can certainly calm down and understand the mathematics behind this — and take reasonable actions to minimize risk. Making sure to have two to three weeks of food and necessary medicines on hand is a great preparation. Avoid hoarding supplies, especially things like breathing masks, which are only helpful if you are in at-risk situations. Hopefully this list of questions and answers helps put things in proper perspective.
The CDC has suggested that social distancing measures and limiting nonessential travel can help slow the spread of the disease in communities. Many conference organizers are also facing pushback from attendees, sponsors, and contractors about attending or working at events. In some cases, local governments are forcing the cancellation of large events. For this reason, many organizers are deciding to postpone events to a later date or put things on hiatus while this situation is addressed. In general, you should consider that minimizing your exposure to large groups is the most socially responsible thing to do. And if you must travel, you might consider driving versus flying or taking a train. Some are advising that all unnecessary gatherings and activities be canceled.
For more comprehensive and scientifically detailed answers than these, I encourage you to stay abreast of what the CDC and WHO have to say. Again, I am not a medical expert — just someone good at reading, math, and basic reasoning. We must all encourage straightforward information sharing and prevention methods and discourage panic. Together, we can get through this.
The coronavirus outbreak is rapidly evolving. To stay informed, check the U.S. Centers for Disease Control and Prevention and your local health department for updates. If you’re feeling emotionally overwhelmed, reach out to the Crisis Text Line.