Sunday, August 22, 2021

If I already had COVID, do I need the vaccine?

If I already had COVID, do I need the vaccine?

(This is a significantly updated version from a post I wrote 8 months ago)

The quick answer: Yes.

The long answer:

I used to be in the “I had COVID, so I may not need the vaccine” camp. 

Although, I was actually in the “I had COVID, I don’t need a vaccine… not for now at least, and maybe not ever, but we will see” camp. 


I was a few hours into my 12-hour shift in the emergency department in late November 2020. As a physician who had been treating COVID at every shift for about 10 months at that point, I knew what I was feeling now was more than just fatigue. 

Waking that morning, I felt like I had just not slept well. But as I got to work and started seeing my first few patients, I was dragging more than a cup of coffee would turn around. Then I started to feel achy and a little lightheaded. 

I pulled the charge nurse aside and told her, "I think I'm sick." I took a swab and went into the staff bathroom to use the mirror. I stuck that q-tip as far in as it would go. Eyes watering, I did it a second time to make sure I got a good sample. 

I then waited for about 45 minutes for the results, looking at the schedule to see who would be available to cover for me if my test came back positive. Knowing my already tired colleagues were going to have to pick up my slack. 

Then the call came. I was positive. My partner was on the way to cover the rest of my shift, and I was going home for 10 days.

I went into the breakroom with my mind whirling. Honestly, I almost started to cry. But it wasn't out of fear or anxiety. It was a mix of emotions, but the strongest was probably relief. 

There is a scene in the movie Waterworld where a very old man is forced to daily work at the bottom of a large, dark oil tank, every day, alone, likely for decades, floating on a little boat, measuring the oil level. Hour after hour. Year after year. Someone drops a flare into the tank from the opening at the top. The old man has a few seconds left to live. He knows that as soon as the flare hits the oil, his hell will be destroyed, him with it. The old man just stands in his boat watching the flare fall and says, "Thank God."

That is obviously way more dramatic than what I was dealing with, and I knew, based on my own age and health, that I was very low risk and likely would do very well with this infection. I had been fighting this beast for months, day after day, hour after hour, and I was tired. I was worn out. Physically and emotionally. A forced, 10-day reprieve seemed like a gift. Being sick seemed almost worth it. 

But I also knew that my infection was, and likely already had, exposed my family, including my older parents and my son with asthma. Working in the emergency department, I was seeing the sickest of the sick, those with every risk factor. But I was also seeing the exceptions to the rule, those with no risk factors. And I was seeing a lot of death. Again, while most people survived, I was seeing the worst results of this pandemic. I knew that while the odds were still in our favor, it was still a gamble as to who in my family could possibly be one of those exceptions.

Within a few days, my wife and kids all developed symptoms. My wife and I, following the statistics, had much worse symptoms than my kids, including my son with asthma. They bounced back within about 2 days. My bad symptoms lasted for about 7 days. I slept 15-18 hours a day for a few days in there. But then I recovered. I had lingering symptoms for a few months, mostly fatigue and reduced stamina for the farm work I would normally do through the week when I wasn't working in the ER. But my family and I had a relatively quick and uneventful recovery.

That’s my COVID story. I am sure you have yours as well. And they are important.


When I was an active-duty Air Force physician, one of my jobs was to manage the immunization clinic. I did this for four years at smaller bases overseas. The military is very prevention minded, and we gave (and got) a lot of vaccines. We also reported any adverse reaction into the Vaccine Adverse Event Reporting System (VAERS). This is a national vaccine safety surveillance program. Most of these adverse reactions were very mild, but we reported them. We had a few more serious reactions, but these were not severe. All this to say that I understand vaccines are not without risk. Any medicines, including lifesaving, beneficial ones, have the risk for side effects. And sometimes, these side effects are very significant. 

With that experience and knowledge, considering what we were dealing with in my local emergency department and what was happening globally, I was thrilled that we had a COVID vaccine coming. I was closely watching the data from the clinical trials. I was planning on getting the vaccine as soon as I was eligible. 

But then I got COVID.

And about 2 weeks after I was diagnosed with COVID, the first vaccine (Pfizer) was released to the public.
By then, I had poured into the data on what the human body does after a COVID infection.

The data showed those who had moderate to bad symptoms of COVID had very good immune response. 
Let me briefly elaborate on this for a minute. 

Remember that COVID-19 is the manifestation of symptoms from infection by the SARS-CoV-2 virus… sort of like HIV (Human Immunodeficiency Virus) causes symptomatic AIDS (AutoImmune Deficiency Syndrome). 

Based on the data, those who had SARS-CoV-2 infections with very mild to no symptoms seem to have shorter-lived antibodies… the immune system basically said, “That wasn’t so bad. I don’t need to store a response to that infection for too long”. 

Those who had very bad symptoms, like extended hospital stays, intubated, etc., also have shorter-lived antibodies… the theory is that the immune system was so beat down that it basically was too exhausted to mount a good response. 

But those in the middle, those with moderate to bad symptoms, seem to create the strongest and longest lived antibodies. It’s a Goldilocks type thing… not too mild, not too severe, but just right in the middle. 

Well, that’s what I had. Moderate COVID symptoms. So, based on the data, I knew I had a very good chance at being protected from this pandemic. In fact, when I write this in August of 2021, it appears that those with moderate symptoms likely have antibodies against SARS-CoV-2 that will last for at least 18 months, maybe longer still. 

(With that said… newer data show that even those with very low levels of remaining antibodies will probably have some protection, but it just may take longer for the immune system to mount an effective response.)


Vaccines works by making our body think it was infected by a bad virus or bacteria that causes a disease (tetanus, rabies, polio, influenza, etc.). When our body is infected (or thinks it is infected), it creates special cells called antibodies that remember what the bad virus or bacteria look like… it’s kind of like the antibodies are the “Wanted Posters” for the bad guys.

The next time the antibodies see the bad virus or bacteria, they recognize and attach themselves to that bad virus or bacteria. This prevents the virus or bacteria from entering cells to cause an infection, but it also calls in other immune cells to attack and kill the bad virus or bacteria.

If your body encounters the real virus or bacteria, the immune system attacks it. The result is that you get a very mild infection with very mild symptoms or even better, you don’t get the infection at all.

Now there is always the possibility that any virus will mutate... that’s honestly very common with viruses, and we had no reason to think SARS-CoV-2 (the virus that causes COVID-19) would be any different in that sense. I said this 8 months ago, and this has proven to be true.

So when other strains (variants) of COVID develop, will that new strain be recognized by our immune system if we already had COVID. Another way of saying this is, “If my body developed antibodies to one strain (variant) of COVID, will my immune system (antibodies) recognize the variant and appropriately respond to it?”

Well, it depends on how much the virus mutates. Remember, a vaccine (and natural immunity) causes the development of antibodies that “recognize” that bad virus. If the virus mutates a little bit, it’s likely that the virus will still be recognized by the antibodies. Kind of like if your best friend cut their hair... you would still recognize them.

Many virus mutations are almost entirely unnoticeable. They are small changes that don’t do much to the virus or the host. Kind of like if your best friend changes their socks. No one really notices or cares. 

But occasionally, a virus may mutate a whole lot, and then maybe the antibodies won’t recognize the virus. Sort of like if your best friend cut and dyed their hair, completely changed their wardrobe, wore a big hat, and spoke in a foreign accent. You may still recognize them, but maybe you wouldn’t.


And this finally brings us to my change from waiting to see what would happen (and not getting the vaccine yet) to finally deciding to get the vaccine.

We are now seeing patients who are getting COVID a second time... this means that either their antibodies didn’t last long enough or the virus mutated enough to fool the “wanted ad posters” (antibodies) of our immune system. And all evidence points to the latter. 

The COVID virus has finally mutated enough (in my educated opinion) that the vaccine is needed. Again, this is proving out in the national data and in my local emergency department.

There have been dozens and dozens of mutations of the SARS-CoV-2 virus (if you skipped ahead, this is the virus that causes COVID-19). Again, this is no surprise. It was expected by everyone who knows and understands virology. Honestly, there have likely been thousands of times that number of mutations, but the vast majority of these are unnoticed without full genome sequencing. There are currently (August 2021) four “variants of concern” and four additional “variants of interest” that are being tracked by the experts. The current variant that is causing so much trouble, and is responsible for the current spike in the U.S., is Delta… also known as Cars-CoV-2 Variant Delta B.1.617.2. 

This Delta Variant is very contagious and seems to be effecting younger people more than the initial virus did. Again, this is also what I am seeing in my local emergency department. I recently had to admit my first under-18-year-old patient with COVID, and I have been treating patients with COVID for over 17 months now. 

Right now, almost all cases of COVID in the United States are caused by the Delta Variant.

Currently, greater than 90% of the deaths from COVID-19 in the United States are occurring in unvaccinated individuals. 

Let me say this again… almost all the deaths from COVID-19 now are in UNVACCINATED people!

Current data show that if you’ve had COVID previously, you are TWICE as likely to catch SARS-CoV-2 a second time if you are unvaccinated than if you had the vaccine.

And again, to be clear, the vaccine doesn’t prevent you from getting COVID, but it increases your chance of staying out of the hospital (and my emergency department) and increases your chance of surviving it. 
As I have said previously, the COVID vaccine is like wearing a bullet-proof vest in a gun fight. You could still get shot in the head (and die) or get shot in the leg (and be seriously injured), but your chances of survival are greatly improved.

I would want a bullet-proof vest if I was in a gun fight. 

This is why I had the COVID vaccine, even though I had COVID.

This is why my wife had the COVID vaccine, even though she had COVID.

This is why my children (12 and older) have had the vaccine, even though they had COVID.

I encourage you to do the same.

1 comment:

Rachel said...

Thank you and John for sharing his perspective. I appreciate the facts delivered in an understandable way! Praying for John and all the healthcare providers (and their families).