Flu season is upon us, and amid the Covid-19 pandemic, it is more dangerous than ever. Under normal circumstances, the flu kills as many as 60,000 people each year in the US alone. While the mortality rate of the Influenza virus is below 0.1%, the Covid-19 virus has a mortality rate of 3-4%, and has killed over 200,000 people in the US alone since the outbreaks first began less than a year ago. So not only is the mortality rate of Covid-19 high but the infection rate is also around 2x worse than that of the flu.
Scientists use the R0 (or Basic Reproduction Number) to describe how contagious a disease is. The seasonal flu has an R0 of 1.3. This means that each person with the flu will get 1.3 additional people sick, on average. After 10 rounds that is 56 people with the flu. Covid-19 has an R0 of 2-2.5. That may not seem like that big of a difference but after ten rounds of a person getting 2 people sick, that’s over 2000 people!
This does not happen with the flu. Not only do we have a flu shot, but the flu is not nearly as deadly. People like to compare the flu to Covid-19 (they especially did in the early months), as some of the symptoms are similar. Notably, deaths due to Covid-19 and deaths due to Influenza are both usually caused by developing pneumonia. However, the numbers make it clear that Covid-19 is not like the flu. One big difference is the incubation period, the period before people feel sick. The average flu incubation period is just 2 days. After being infected, you soon feel sick and are contagious. However, once you have contracted Covid-19, the incubation period is anywhere from 5 – 2 weeks. Scientists believe that during this time you could be contagious. For two weeks you could be spreading it, unbeknownst to you!
The next big difference is your own immune system. The flu has been around for ages and when flu season happens there are always a number of people who are already immune, either because they have gotten their flu shot or because they have already had that strain of flu. Because sick people can only spread to people who are susceptible, the people with immunity can create a sort of shield to block the virus. With Covid-19, no human immune system has seen this virus before and there is no vaccine. This leads it to spread like wildfire. Some businesses are opening up a little again, but we are in flu season! Do not go out for anything that is not essential! If you have to go out, remember to always wear a mask, stay 6 feet away from people, and wash your hands for at least 40 seconds in order to stay safe. Flu season is going to be really bad, but with these precautions we can limit the spread.