Barbara Walters, trail-blazing professional woman, ubiquitous news presence, and all-around tough cookie, has been diagnosed with the chicken pox. Chicken pox? News hounds everywhere want to know: what is a self-respecting octogenarian doing with a pediatric disease? A disease that at least 98 percent of Americans over 50 already have had? Does this have to do with the injury last week when she slipped or fainted and clunked her head à la Hillary Clinton? Was she jealous of Hillary? Upset? Was there anything, painful though it might be, she would like to tell her mother, if she were alive? Ahh yes, it’s OK—here’s a tissue.

2011 TV Land Awards Show

Barbara Walters presents the "Legend Award" on stage during the 2011 TV Land Awards show, on April 10, 2011, in New York. (Charles Sykes/AP)

Well chicken pox happens even to adults. Even to 83-year-old adults. But in Walters’ investigative spirit, let’s look into whether the story might be a tad more complex than what we’ve been told. The virus that causes chicken pox, varicella-zoster virus, or VZV for those in the know, is a tricky customer. The single virus causes two diseases—chicken pox (vide above) and shingles, that stripe of painful blisters that paints one side of the body (usually the trunk) or the other. Incredibly, the exact, self-same virus causing chicken pox in a kid in a sandbox 50 (or 80) years ago is the one that causes shingles in 2013. It has lain dormant, somehow, for all those decades only to reawaken—sometimes because of an illness like cancer or a medication like steroids that weakens the immune system. Walters’s 2010 surgery for a faulty heart valve, though, would not classify as such a medical condition.

Once in a while, the virus can escape its narrow, shingled corridor and spread throughout the body—so-called disseminated shingles. This can look for all the world like primary kid-based chicken pox. So it may be that Walters has this variant on shingles. But disseminated infection is almost exclusively the domain of persons with abnormal immune systems, and as noted there is no information to suggest Walters has anything but a normal immune system.

That said, she is 83. Sure, 83 may be called the new 63 or 43 or 3, but actually in most ways, 83 remains 83. And scientists do talk, unflatteringly, about immune senescence, a fizzling out of immune prowess not unlike the parallel geezer-driven fizzle occurring in many other body parts. The evidence for weakening immunity with age, though, is not as strong as you’d think. Surely advanced age is accompanied by increasing numbers of slings and arrows, as well as large amounts of outrageous fortune. But when an older person gets sick, becomes weak, slips, breaks a hip, sustains an abrasion that becomes infected, has a blood clot, goes to an ICU, becomes weaker yet from a prolonged stay, has another pneumonia, etc., is that because the old immune system ain’t what it used to be? Or because the series of unfortunate events that we call old age tends to find and sicken the elderly?

And chicken pox, let the record show, is not a great disease in adults. Though chicken pox kills few people, adults generally are the ones it does kill, usually in the form of a viral pneumonia. Given Walters’s fit condition and the likelihood that the chicken pox was caught early (she showed the rash while already in the hospital for her head trauma), she ought to make a complete recovery.

But, cub reporters and fledgling Waltersites, the real question is this—shouldn’t Walters have had chicken pox by now? Though much about Walters’s personal life is unknown, at least to those of us who have not read her autobiography, Audition, she did grow up in a family with siblings and has raised a child herself. Generally speaking, in the pre-vaccination era, a person growing up in a house with siblings is destined to get the chicken pox, since, though he or she might dodge the infection at school or at camp, eventually a sibling is sure to drag it home.

Ditto with parenthood: her daughter, Jacqueline, born in 1968, long before the introduction of the chicken pox vaccine in 1995, almost surely got the chicken pox as a kid—90 percent of all kids did in those years, at least in the U.S. (rates are lower in warmer, equatorial regions). Which means that Walters likely was exposed then, too; or else when she went with the daughter to the various birthday parties, school plays, and other activities that crowd a child’s young life—surely someone at one of those events was incubating the virus.

Given Walters’s fit condition and the likelihood that the chicken pox was caught early, she ought to make a complete recovery.

To be complete, though, we must consider, possibly, that the facts given are the actual facts, that perhaps Walters indeed somehow never developed chicken pox as a kid or a youngish parent and now improbably but truly has the disease. If so, with her current illness, Walters, the inveterate news chaser and shibboleth toppler has herself become an important story—not as a celebrity sparkler to fill a slow-ish news day, but because she has demonstrated for all to see that most impossible-to-explain fact about the way things work.

Here’s the situation: in a population of 7 billion people, the one-in-a-million event will always occur. Every day someone will develop a horrible complication from a routine procedure; a bullet will sail through a person’s chest and miss the heart by a whisker; someone will win Lotto; or a woman in her 80s will develop chicken pox. But as with Barbara Walters and her chicken pox, the fact that it happens doesn’t mean it’s news really—it’s not a trend or an epidemic or an oversight by dim bureaucrats, or a reason to line up the lawyers. It means just one thing: that very rare things happen. Often. Left and right. In fact, they happen every day.