People in the U.S. and around the globe are intently following news reports and other data about the COVID-19 pandemic. Most of us are eager to know when there might be an end in sight, but unfortunately, Americans continue to die at an alarming rate. The death rate decreased earlier in the summer but has increased again recently. According to data collected by Johns Hopkins University, over 180,000 people have died so far in the U.S. due to COVID-19.
Many people want to know how the mortality (or death) data for COVID-19 compare with that of a regular flu season. But it may not be an “apples to apples” comparison, as you’ll see below.
How are COVID-19 and the flu different?
COVID-19, which stands for coronavirus disease of 2019, is an infection caused by a type of coronavirus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The infection we know as “the flu” is caused by the influenza virus. Both are viral, respiratory illnesses, but they are not the same thing.
Both coronavirus and influenza are spread by respiratory droplets and close contact. There are some other similarities between the two, including overlapping symptoms, which you can read about here. But because coronavirus and influenza are different viruses, a vaccine or treatment for one won’t have any effect on the other. In other words, the flu vaccine will not prevent you from getting COVID-19. That is one of the biggest differences between the two right now: A flu vaccine exists, whereas a COVID-19 vaccine does not.
Other differences include length of time between infection and symptoms and how long the symptoms last.
Coronavirus vs. flu deaths
The first thing to know is that deaths due to COVID-19 and the flu are not counted in the same way. This means comparing the numbers isn’t as straightforward as we would like.
Each death due to influenza in the U.S. does not have to be reported, so there is never a direct count. Each flu season, the CDC estimates deaths from the flu based on in-hospital deaths and death certificate data. They continue to update the data on their website as they collect it. Therefore, numbers from the last two flu seasons are not considered final just yet.
Conversely, each death due to COVID-19 is being recorded. The numbers you see and hear about are not estimates. So you can see how comparing mortality rates between the two isn’t exact at this point.
That said, here’s a quick look at the number of cases and deaths for the last two flu seasons (again, not final) and COVID-19 to date:
|2017-2018 Flu||2018-2019 Flu||COVID-19|
|Cases||45 million||35 million||5 million|
Breaking down the data
As with most topics in epidemiology, interpreting the numbers is complex. The data should be sound before any comparisons can be made. For example, health organizations are collecting data on COVID-19 differently. Should they look at only confirmed cases? Or also probable cases? How do they account for undertesting, especially in the first few months of the pandemic? Or delays in reporting?
Additionally, there are differences in how the numbers are reported. For example, this dashboard reports data collected from various state and county health departments, whereas the CDC uses a different process to confirm deaths before reporting.
But there are other ways to evaluate the numbers. In the spring of this year, this paper found that weekly death counts of COVID-19 were much higher — on average 20 times higher — than weekly deaths from the last several seasons of the flu at its peak.
Fortunately, weekly deaths from COVID have decreased in recent months. As you can see here, recent weekly deaths in the U.S. are not as high as they were in the spring, which is obviously good news. The decrease in the number of deaths is likely due to better protection of people over 65 years old, earlier diagnosis, and better treatment.
Flu vs. COVID-19 fatality rate
Mortality rate measures how frequently people die in a specific population during a specific time period. One way of looking at that is with the case fatality ratio. This is the proportion of people with confirmed cases of a particular condition who die due to that condition.
According to this dashboard, the case fatality ratio of COVID-19 in the US is 3.1%. The case fatality rate for influenza will obviously change year to year. But news reports and the World Health Organization often estimate it at around 0.1%. While the medical community is still learning about mortality from COVID-19, it does appear to be more deadly than the flu.
There is obviously a wide range in COVID-19 case fatality numbers by country. This can be due to many things, such as how much testing is going on, the age of the population, and access to healthcare. For example, if more people are being tested, the case fatality ratio will decrease.
It’s also too early to determine anything about seasonal patterns, since this pandemic has been going on for less than a year. What we do know is that certain people are at higher risk for complications, including death, from COVID-19. This is true of the flu as well. When comparing COVID-related deaths in different geographic areas, it becomes clear that age plays a role. In addition to older age, certain medical conditions can increase people’s risk for having more severe disease and complications (including death).
The bottom line
Although COVID-19 and influenza may look the same to some people, they are definitely not. The COVID pandemic continues to be a danger to public health and should be treated as such.
If you think you might have COVID-19 or the flu, it’s best to limit your contact with others for the time being to avoid spreading your illness. Contact your healthcare provider to inquire about next steps and testing. Read here for more information on when to seek immediate help for symptoms.