Many people have wondered whether COVID-19 will eventually become endemic, meaning it starts to spread at a much lower rate and behaves more like the flu, for example. With cases of COVID-19 increasing again all around the world due to the new B.A.5 Omicron subvariant, it seems like we’re far away from that point. As the epidemiologist Dr. Michael Osterholm says, while many people are done with the pandemic, the pandemic isn’t done with us. However, a group of researchers recently published a study that provides us with some ideas of when the COVID-19 pandemic may finally start to die down and become endemic if we’re lucky.

The researchers began by looking at the spread of another coronavirus similar to the COVID-19 virus in a population of lab rats. The researchers infected a few rats with this coronavirus and then let these rats interact with the rest of the lab rat population. The researchers gave the rats PCR tests and observed how many got infected with the coronavirus after being exposed to the first infected rats. They also observed how long the infection lasted in each rat and how many rats got reinfected later as the virus continued to spread and create new variants like the COVID-19 virus does. The researchers also vaccinated some of the lab rats to see how much the vaccine reduced the spread of the virus.

 After watching the virus spread in the lab rats for several months, the researchers gained an idea of how long it takes for the spread of the virus to die down. Once the researchers had this data, they used it to help create computer simulations of the spread of the COVID-19 virus in humans. The researchers combined what they observed when the virus spread in the lab rats with everything we know about COVID-19. They took into account how long people remain infectious with COVID-19, how many people they are likely to spread it to, how vaccination changes the spread of the virus, how often new variants emerge, and more. After putting all of this information into their computers, the researchers ran simulations of the spread of the COVID-19 virus to get an idea of how long it would take for the virus to become endemic – that is, how long it took for the spread of the virus to die down so that only a small number of people would get it. The average time it took to reach this point in their simulations was 4 years, though it could be as little as 3 years or as long as 5 years.

Of course, it is important to keep in mind that these are simulations and in the real world a lot can change that might be unexpected. However, the advantage of this study is that the simulations were made after watching a coronavirus spread and die down in rats in real life and were not just based in theory on how the virus might spread and die down. If their simulations are close enough, it could mean that we could hopefully see COVID-19 start to ease back a little in another year or so. Until then, make sure to stay aware of the transmission levels in your community, wear a mask indoors if there is high transmission of COVID-19 in your community, and stay up to date on your COVID-19 vaccines.

Computer Simulation – A computer simulation is a computer program that acts out events in a way that is similar to how those events would happen in real life. For example, scientists can create a computer simulation of a car crash so they can see what might happen when you crash a car without having to crash a car in real life.

Mullin, S., Wyk, B. V., Asher, J. L., Compton, S. R., Allore, H. G., & Zeiss, C. J. (2022). Modeling pandemic to endemic patterns of SARS-CoV-2 transmission using parameters estimated from animal model data. PNAS nexus, 1(3), pgac096.