We have seen how the lethality of Covid-19 rises exponentially with age. It is such that if a person over 80 years old catches the disease, the odds of survival are not good.
There is a reason why older people are much more likely to die of Covid-19 than are their children and grandchildren. From about the age of puberty onward, the human immune system declines in its ability to protect us from a host of threats, including Covid-19. One of the prime drivers of this decline is a condition called thymic involution, which is the decline in size and function of the thymus gland.
The thymus gland is responsible for the production of T cells, which are important in providing cell-mediated immunity. It is these T cells that recognize an invasion of a pathogen, such as the SARS-Cov-2 virus, and attack the invader.
As the thymus gland declines with age, a person’s ability to fight off infectious diseases declines along with it. This process is covered in a paper available in Journal of Royal Society Interface, titled “COVID-19 hospitalization rates rise exponentially with age, inversely proportional to thymic T-cell production.”
We have seen that Covid-19 death rates rise exponentially with age. The size and functional ability of the thymus gland decreases exponentially with age, after puberty. The older a person is, the less effective their thymus is at mounting an immune response to Covid-19 through the production of T cells. Cases of Covid-19 in seven countries (Spain, France, Denmark, Canada, USA, England, and Switzerland) all showed an exponential rise in hospitalizations for severe disease, with a linear increase in age. Across all those countries, the number of hospitalizations doubled for every 16 years of age. That means that a 56 year old Covid-19 patient was twice as likely to require hospitalization as was a 40 year old patient. A 72 year old patient was twice as likely to require hospitalization as a 56 year old patient and four times as likely to require hospitalization as a 40 year old patient.
It is interesting that the rate of hospitalization with Covid-19 as a function of patient age is a close match to the rate of thymic involution with age for all age groups over 20 years of age. Between puberty and age 20, something else is going on that appears to be protective of older teenagers. Perhaps a way of reversing thymic involution would reduce a person’s susceptibility to severe Covid-19 as well as a host of other infectious diseases.
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.