The Institute on Aging recently posted on how seniors can strengthen their immune system: and family and friends can help. They offer immune-boosting strategies that make sense for seniors and even pre-seniors or those with autoimmune conditions.
Looking at the list, I don't see any surprises, except for hygiene. So this really is just a reminder - which we all need to help keep us moving forward.
As for hygiene, it makes sense that we need to avoid introducing germs, bacteria and virus into our body. And, family caregivers play an important role in helping implement and maintain these strategies.