Some people have never yet had COVID (so far so good, this writer included); others are on their third bout already; others have not been so lucky and are no longer with us to share their stories.

Obviously, even the healthiest and/or most careful person can get sick, and it would be folly to be complacent and think “I’m not a person who gets sick; that happens to other people”.

Nor is COVID the only thing out there to worry about; there’s always the latest outbreak-du-jour of something, and there are always the perennials such as cold and flu—which are also not to be underestimated, because both weaken us to other things, and flu has killed very many, from the 50,000,000+ in the 1918 pandemic, to the 700,000ish that it kills each year nowadays.

And then there are the combination viruses:

Move over, COVID and Flu! We Have “Hybrid Viruses” To Contend With Now

So, why are some people more susceptible?

Firstly, some people are simply immunocompromised. This means for example that:

• perhaps they have an inflammatory/autoimmune disease of some kind (e.g. lupus, rheumatoid arthritis, type 1 diabetes), or…
• perhaps they are taking immunosuppressants for some reason (e.g. because they had an organ transplant), or…
• perhaps they have a primary infection that leaves them vulnerable to secondary infections. Most infections will do this to some degree or another, but some are worse for it than others; untreated HIV is a clear example. The HIV itself may not kill people, but (if untreated) the resultant AIDS will leave a person open to being killed by almost any passing opportunistic pathogen. Pneumonia of various kinds being high on the list, but it could even be something as simple as the common cold, without a working immune system to fight it.

See also: How To Prevent (Or Reduce) Inflammation

And for that matter, since pneumonia is a very common last-nail-in-the-coffin secondary infection (especially: older people going into hospital with one thing, getting a secondary infection and ultimately dying as a result), it’s particularly important to avoid that, so…

See also: Pneumonia: What We Can & Can’t Do About It

Secondly, some people are not immunocompromised per the usual definition of the word, but their immune system is, arguably, compromised.

Cortisol, the stress hormone, is an immunosuppressant. We need cortisol to live, but we only need it in small bursts here and there (such as when we are waking up the morning). When high cortisol levels become chronic, so too does cortisol’s immunosuppressant effect.

Top things that cause elevated cortisol levels include:

• Stress
• Alcohol
• Smoking

Thus, the keys here are to 1) not smoke 2) not drink, ideally, or at least keep consumption low, but honestly even one drink will elevate cortisol levels, so it’s better not to, and 3) manage stress.

See also: Lower Your Cortisol! (Here’s Why & How)

Other modifiable factors

Being aware of infection risk and taking steps to reduce it (e.g. avoiding being with many people in confined indoor places, masking as appropriate, handwashing frequently) is a good preventative strategy, along with of course getting any recommended vaccines as they come available.

What if they fail? How can we boost the immune system?

We talked about not sabotaging the immune system, but what about actively boosting it? The answer is yes, we certainly can (barring serious medical reasons why not), as there are some very important lifestyle factors too:

Beyond Supplements: The Real Immune-Boosters!

One final last-line thing…

Since if we do get an infection, it’s better to know sooner rather than later… A recent study shows that wearable activity trackers can (if we pay attention to the right things) help predict disease, including highlighting COVID status (positive or negative) about as accurately (88% accuracy) as rapid screening tests. Here’s a pop-science article about it:

Wearable activity trackers show promise in detecting early signals of disease

Take care!