Chongo should note that "at the center" - as he describes it, is usually where the drain hole is located. Where all the SHIT goes down the drain.

On the real subject:

As we're all more or less constantly exposed to a variety of infectious agents, it is possible that the constant exposure may help to keep our individual immunities active and healthy.

"Over sanitizing" has been implicated by some as a cause of the galloping increase in the prevelance of asthma in youngsters of recent generations. The verdict is still a little shaky, but a few studies have indicated that children, before the age of about two, who are deprived of association with pets (and the change to be exposed to all the crud and corruption thereby encountered) appear to lack full development of their immune systems, and are more prone to later infections and other symptoms of undeveloped immune response.

A classic case, fairly generally accepted, is that the three versions of polio, two of which were relatively mild, each provided at least partial immunity to all of them. When the Swiss sponsored a massive program to provide sanitary plumbing throughout the country, all three varieties were reduced in frequency, so that the entire population lost their traditional resistance. When the paralytic strain reappeared in a population with no resistance, it spread rapidly into a world wide epidemic with very severe consequences.

Achieving and/or maintaining the "total absence" of influenza might not be a worthy goal, if the annual exposure of a fairly large percentage of people to the commonly "mild" strains confers even the slightest additional resistance to the occasional more deadly kinds.

It is something of an open question, still waiting for better-informed opinions.

John