The novel coronavirus is dangerous and almost everyone in the world can still be infected. In order to stop COVID-19, we will need to achieve herd immunity. We can reach herd immunity through vaccination or by lots of people getting sick and recovering from COVID-19. There’s no vaccine yet, and we don’t know when one will be ready. So why don’t we just let everyone get infected and get on with our lives?
If we allow COVID-19 to spread too quickly, and many people become sick all at once, then our hospitals will be overwhelmed. When hospitals are overwhelmed, they can’t take care of everyone to the best of their ability and people die unnecessarily. Flattening the curve prevents this by keeping the number of sick people low enough that we can treat everyone..
To illustrate this point, let’s assume—even if we do not know this for sure—that you can only get COVID-19 once. Based on how infectious COVID-19 is, studies estimate that we will need 62-78% of the world’s population to be immune (from recovery or a vaccine) in order to achieve herd immunity. There are more than 7.7 billion people in the world. So, without a vaccine, 5-6 billion people would need to become infected in order to achieve herd immunity. If all of those people were to become infected in a short period of time, there is no way we could care for them all. It would be a disaster on a scale that’s difficult to imagine. Millions and millions of people could die unnecessarily.
Flattening the curve also buys us time to develop vaccines and treatments for COVID-19. The hope is that if and when a vaccine is available, herd immunity can be achieved without more people getting sick. If effective treatments are found, the illness will be less deadly to those who catch it.
While we wait for a vaccine and effective treatments to be found, keeping the rate of new infections as low as possible decreases the number of people who will die in the meantime.
Last Revised: May 14st, 2020, at 4:12pm ET
Science Review: GSN, ERS, JAB