A Kentucky judge rejected the claims made by a teenager who sued his local health department for temporarily barring students at his school who aren’t immune against chickenpox from attending classes and participating in extracurricular activities.

This article prompted a little thought experiment.

Chickenpox used to be a routine childhood illness.  For a couple of weeks, kids who contracted the illness were very contagious and experienced discomfort.

Death was rare, but it did happen.

Finally, in 1995, the chickenpox vaccine arrived.  It was safe and effective. Ironically, our son was suffering from chickenpox at the time this became news.  I was kind of surprised at the level of misery he was experiencing.

With the arrival of the vaccine, chickenpox as a childhood illness virtually vanished.

Here’s the catch: The varicella virus has not vanished.  Anytime someone gets shingles, they shed the virus.  True, a person with shingles is far less contagious than someone with chickenpox. Yet, when a person with active shingles meets someone not immune to chickenpox, there is the potential for a new chickenpox case.

It is important to emphasize that chickenpox is far more severe in older people.  Prior to the vaccine, it was common to hospitalize some patients in their late twenties with cases of chickenpox.

Chickenpox is even worse if you are pregnant.  Occasionally, such patients even died.

Anti-vaccine patients avoid the vaccine entirely.  They also avoid chickenpox because the disease has become fairly rare in this country. Unfortunately, as they get older, they may eventually encounter the disease and they will become very sick.  In fact, they may get very, very sick.

Repeat that point:

Chickenpox in kids is bad, but rarely a catastrophe.

Chickenpox in pregnant or older people is a disaster.

Thanks to herd immunity, these unvaccinated kids will become older unvaccinated adults.  All is well until a family member visits and mentions an odd rash on one side of their face.  The unvaccinated older adult looks at it closely and may even touch the visitor’s shingles rash.

Boom. Soon, you will have a very, very sick older adult with a horrible case of chickenpox.

What does chickenpox look like in a 45 year old? It is probably really awful, but I’ve never seen such a thing.

The oldest case I ever saw was in a 29 year old, and she was amazingly sick.

What happens in a 60 year old?  I bet the fatality rate starts to climb.

On the bright side, there are several things which could blunt this doomsday scenario:

Drugs like Valtrex are pretty good.

Vaccine campaigns may catch a lot of these older kids of anti-vaxxers to get them immunized.

Patients with Shingles do not tend to shed a lot of virus and are not terribly contagious.

(Side note:  More than three decades ago, my nurse wife with zero varicella immunity provided care to many inpatients with shingles and did not contract the disease until she wandered past a contagious kid in a museum years later.)

People speak of “chickenpox parties” and they sound insane.  Yet, in the old days before vaccines, this almost made sense: “Get the disease now when the severity is less.”

What about the anti-vaccine kids?

I know. The correct answer is to get the vaccine now and stop worrying.

The point is: Chickenpox as a disease is evolving thanks to this terrible mix of the vaccinated and unvaccinated.  This could be really terrifying.

Steven Mussey is an internal medicine physician.

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