Why Are We Treating COVID Differently From the Flu?

“These are strange times we’re living in, aren’t we?”

As a primary care physician on the front lines of this COVID-19 pandemic, I’ve lost count of how many times I’ve remarked this statement to my patients.  COVID has completely upended our routines and has drastically changed the way that we “do life” currently.  We are all concerned about what this “new normal” is, and how long we can expect it to continue.

With this comes a lot of frustration and confusion.  Wait a minute, isn’t this a whole lot less prevalent than the flu?  Don’t more people die to influenza every year compared to COVID-19?  Don’t most people with COVID-19 have minimal – or no – symptoms?  This comparison of COVID-19 with influenza is a frequent topic of conversation, and I’d like to share my thoughts on the matter.  These are the same talking points that I explain to my patients in my daily practice.

The TL:DR version is this – YES, influenza and COVID-19 are markedly different.

What follows are seven points of difference between influenza and COVID-19.  A lot of time could be spent on each point, but for the purpose of this post I’ll keep the explanations as succinct as possible…

1.  We can test quickly and easily for the flu, but we can’t for COVID-19.

A “point of care” test (POC) is a diagnostic test that can be done at the bedside, with rapid results.  We’ve all had experience with a flu test done at a doctor’s office, urgent care, etc. – this is an example of a POC test.  Rapid testing such as this is a very powerful tool against something like a virus, which has a high probability of being transmitted from one person to another.  I have this tool against the flu, but I currently do not against COVID-19.  Granted, things are much better now than they were a few months ago, when I couldn’t even order a COVID-19 test if I wanted to, and I expect them to continue to improve.  As it stands now, however, the absolute fastest test result I can get back for a SARS-CoV-2 PCR (a nasal swab that tests for the actual virus that causes COVID-19) will come back in 24-48 hours.  That’s a huge gap of time where management decisions – such as quarantine actions, gauging risk of close contacts, etc. – are all in limbo while we await the result.

2.  Influenza is fairly recognizable and predictable, while COVID-19 is not.

It is very true that individuals will manifest symptoms differently, but the flu is still recognizable.  A vast majority of people will have some combination of fever (even low-grade), sinus symptoms, runny nose, cough, body aches, and stomach pain.  Very rarely does a case of influenza truly “sneak up” on us in the clinical setting.  On top of this, there is a seasonal predictability.  We are all familiar with “flu season,” and we don’t typically expect to see much influenza in the summer months.

I have neither of these advantages with COVID-19.  The spectrum of symptoms that individuals can have is extremely wide – ranging from no symptoms at all to life-threatening illness.  Sure, there are obvious cases, such as when someone presents with fever, cough, and low oxygen saturations.  But more often, I will see someone with a scratchy throat and a little decreased appetite, and I’ll wonder – could this be COVID?  There does not seem to be a recognizable pattern of symptoms with COVID-19, which makes diagnosis and testing decisions difficult.  Finally, in terms of the seasonality – I think we were all hoping that COVID-19 would start to “fade out” with the warmer weather approaching, but unfortunately this does not look to be the case.  Whether or not there is any seasonal variation with COVID-19 still remains to be determined.

3.  The flu has a fairly predictable disease severity, while COVID-19 does not.

This is a little similar to the previous point, since everyone reacts differently to a viral infection, but we have enough experience with the flu to reasonably predict those individuals who are going to get really sick and those who are just going to feel crummy for a few days.  For me personally, this might be the scariest thing about COVID-19 – I can’t predict who is going to get really sick, and who will have mild symptoms.  I can have two very similar patients – let’s say they’re both in their 40s, both male, both relatively healthy, neither take any medications.  Both unfortunately contract COVID-19.  One develops extremely low oxygen saturations and ARDS (acute respiratory distress syndrome – a very severe inflammatory condition of the lungs) and has to be put on a ventilator.  During the course of treatment he develops a stroke and blood clots in his legs and lungs. 

The other patient gets a runny nose.

Why the difference?  This is a huge focus of medical research right now.  There are some theories, but no definite answers, and certainly not anything that helps guide us in a clinical environment yet.

4.  We have some treatment options for influenza, but less so for COVID-19.

Granted, the treatment options for the flu aren’t great and won’t magically make your symptoms disappear, but we still do have some options.  Most importantly, while these options (medications like Tamiflu and Xofluza) might not do wonders for symptoms, they have been shown to reduce viral shedding – this simply means that it can help someone be less contagious.

There is a media frenzy regarding treatment options for COVID-19, which is probably a topic for another conversation.  The bottom line, however, is this – while some treatment options show modest promise, there are no consensus guidelines on an effective treatment.  We are developing management protocols to better care for hospitalized patients with COVID-19, but there are no definite treatment options yet.  This is especially true for the outpatient setting – a very important point that frequently gets overlooked is the fact that a vast majority of the treatment options being investigated are for very ill, hospitalized patients.  In other words, I basically have no treatment options to offer a patient who has COVID-19 but is not sick enough to be in the hospital.

5.  There is a vaccine for influenza, but not for COVID-19.

There can be lots of heated discussion about influenza vaccination – I get it.  The effectiveness of the vaccine changes from year to year and is never perfect – for the 2019-2020 flu season, the vaccine was 37% effective for Flu-A and 50% effective for Flu-B.  Regardless, for those who choose to get a vaccine, we have one.  Even if it isn’t perfect for that particular season, it is still thought to carry some protection and will likely blunt or reduce symptoms somewhat if you still get influenza after having had the vaccine.  A vaccine for COVID-19 is under development, and is starting phase 1 human trials, but we are still some time away from having one in hand.

6.  We all have “developed” or “residual” immunity to influenza, but not to COVID-19.

Influenza has been around for centuries.  We have all been exposed to an influenza virus, probably dozens of times (at least).  Each time we get exposed to a different strain of the virus, we develop some antibodies against it for protection against future exposure.  While these won’t offer full, or perfect, protection against other strains of the virus, it is likely that it gives some protection, or at least will reduce severity of the infection somewhat.  This is similar to the discussion in point 5 above – even if the vaccine isn’t perfect, the antibodies produced will still offer some benefit.  We simply don’t have this “developed” or “residual” protection for COVID-19, since the SARS-CoV-2 virus is new.

There is a potentially valid counter-argument here – the SARS-CoV-2 virus is a coronavirus, which is a family of viruses that has been around forever.  They are basically associated with the common cold, and we have all been exposed to them.  Could antibodies to these other coronaviruses provide some help?  Possibly.  Could this be why some people have very mild symptoms?  Possibly.  There’s just so much we don’t know about this virus yet.

7.  Mortality rate.

Statistics are hard, and frequently numbers can be manipulated to suit varying positions.  We do have a fairly good handle on the overall mortality (death) rate from influenza, which is much less than 1% (around 0.1-0.2%).  As of right now, the mortality rate for COVID-19 appears to be much higher – conservatively around 0.5%, but some data show as high as about 4%.  Now, I expect this number to decrease as we expand our ability to test, which will therefore catch a larger proportion of people who have mild disease, which would then drive the mortality rate down.  Also, I expect that our ability to treat severe disease will continue to improve as we get more experience with COVID-19.  That being said, there is no doubt that COVID-19 has the potential, in some individuals, to create life-threatening illness – at least as much, or perhaps more so, than influenza.

These are the talking points that I discuss with my patients when they ask why we are treating this COVID-19 illness differently from the flu.  I hope that this has given you some insight from my perspective as a physician.  Has this changed or reinforced your perspective at all?  Anything I missed?  Agree?  Disagree?  Let me know in the comments below!