There is one more action that may give a person a way to enhance trained innate immunity short of catching COVID-19 itself, and that’s to catch a cold. Specifically, a coronavirus cold. I read a great article in the New Scientist that I’ll summarize for you. I urge those of you who want to know more to read the paper listed below.

There are four fairly common coronavirus colds we all get at some time: OC43, HKU1, 229E, and NL63. In a study cited by the article in the New Scientist, researchers collected data from medical records of just under 16,000 patients. Of those, 875 had a documented case of coronavirus colds verified by a test; the rest of the subjects did not. Those who had a confirmed case of one of the types of coronavirus colds had milder cases of COVID-19, fewer required intensive care, and fewer had to be put on mechanical ventilation. The mortality rate was 4.8% in those who had a prior cold and 17.7% without a verified cold test.

The upside is that it seems to provide some trained immunity against COVID-19. The downside is that the immunity seems to wane over the years. I think this research is important because it shows one more way to train the immune system. It may not be practical in the real world, but if you happened to catch a simple cold in the past six months, you may have some innate immunity—if you happened to catch the correct form of the cold virus. For the rest of us, the flu shot is still the best course of action in training our immune system.

What are you prepared to do today?

        Dr. Chet

References:
1. The New Scientist. https://bit.ly/35yxbDY
2. J Clin Invest. 2020. https://doi.org/10.1172/JCI143380.