Will COVID-19 be worse in winter?

Do you ever wonder why your body changes as it gets colder? Or how you see more people catching the flu or a cold in the winter? Common cold coronaviruses have been found everywhere no matter what season. However, in most of the United States, the common cold coronavirus and seasonal influenza infections are at their highest in the winter. Why is this the case? Do these viruses have a favorite season? Let’s find out!

Do you ever notice your nose is itchier in the winter or your lips feel dry? That’s caused by the drier air!  Tiny virus particles love this drier, denser air because they float in the air longer making it easier to infect new people. Do these particles act the same way in the summer? No, the air has different conditions that the particles don’t like! In the summer, the air is hot and humid so the tiny virus particles don’t stay in the air as long which keeps them from infecting new people. This helps fewer people to catch a cold or the flu!

Did you know that the mucus in your nose also plays a role in keeping you healthy? Mucus is very important because it traps little particles that come into your nose from your environment. These particles can be pathogens, like bacteria and viruses that cause infections and get you sick. After your mucus catches these pathogens, it tells your body to sneeze or blow your nose to get these particles out of the body. This is usually the case, but winter weather changes your mucus so it doesn’t do as good of a job protecting you. With the mucus defense down, people can more easily catch a cold or the flu.

So, this is what we know about existing diseases like influenza and other coronaviruses – do we know for sure what will happen with this new virus? There is not enough information about COVID yet to fully understand how it will behave this winter, however, a small study from Australia looked at local COVID cases in March 2020 and compared temperature and humidity. The results show that the drier the air was the more likely people were to get sick.

With more time spent inside and with the reopening of schools, there may be a possibility for COVID-19 to rise again. Unfortunately, we’ll only know once we get there. On that note, social distancing, washing your hands, and wearing a mask will continue being helpful ways to reduce your risk and keep those around you safe.  

Author: Dhara Salazar (BioBus Junior Scientist)
Original COVID-101 article by Gavin Harris MD