Four weeks ago, I told you about my experience getting a Covid-19 vaccination. I had an adventure booking an appointment, and at getting to the Walgreen’s store where the injections were being given, but the injection itself was no big deal. There was a little soreness the next day at the spot where the jab was administered, but that was it. No other post-injection side effects. A couple of days ago, I received my second shot, and this time the experience has been different.

First of all, the weather was fine and the drive to the Walgreen’s store was a breeze. Once again, I waited while a couple of people before me received their injections. And once again, the entire process went smoothly. I barely felt the prick. I even exchanged a little banter with the nurse who was administering the doses. No sweat. Joyce and I drove home, and I ran my usual two mile run around the neighborhood without giving it a second thought. I felt fine.

When I woke up the next day, in sharp contrast to how I felt after the first injection, I did not feel fine.

• I was very unsteady on my feet and felt like I was in constant danger of falling.
• I was fatigued and did not feel like doing anything beyond lying in bed.

Today, I felt better, but the fatigue caused me to take another midafternoon nap. After the nap, I felt almost normal and was able to participate in our monthly Zoom call with my far-flung family.

How can I explain the difference between the after-effects of my first Covid vaccination, which were minimal, and the after-effects of my second shot? The shots are identical, regardless of whether it is your first or second. The difference is not in the vaccine; it is in the patient.

At my first vaccination, my immune system was naïve. It had never encountered the SARS-Cov-2 spike protein before, which is the entry key tool of the virus. After recognizing that protein as foreign, it made a note to be on the lookout for it if it ever appears again. If it does appear again, an alarm bell rings, and the immune system mounts a defensive reaction. That reaction is a war being raged within my body. Now when my immune system detects that spike protein, it comes out fighting. With my body on a war footing, it is not surprising that I did not feel well. I have discovered that my experience is not unusual. Other people have reported little or no side effects from a first dose of vaccine, but definite effects from their second dose.

Today, I was talking to my daughter (via Zoom) and discovered that a year ago, she suffered from a disease whose symptoms were consistent with Covid-19, but she was not tested for Covid while she was ill. Two days ago, she received her first Covid vaccination the same day that I received my second. For the past couple of days, she has had some of the same symptoms that I recently exhibited. This causes me to suspect that her first Covid vaccination was in fact the second time her immune system had encountered the SARS-Cov-2 spike protein, first from an actual viral infection and second from her first, and so far, only, vaccine injection.

From my experience, and from my daughter’s, I believe that feeling bad after a second Covid-19 vaccination is actually a good thing. It means that your immune system recognizes the enemy and will attack it aggressively, should it ever appear again in the future.

BIO:

Allen G. Taylor is a 40-year veteran of the computer industry and the author of over 40 books, including Develop Microsoft HoloLens Apps Now, Get Fit with Apple Watch, Cruise for Free, SQL For Dummies, 9th Edition, Crystal Reports 2008 For Dummies, Database Development For Dummies, Access Power Programming with VBA, and SQL All-In-One For Dummies, Third Edition. He lectures internationally on astronomy, databases, innovation, and entrepreneurship. He also teaches database development and Crystal Reports through a leading online education provider. For the latest news on Allen’s activities, check out his blog at wwwallengtaylor.com or contact him at allen.taylor@ieee.org.