(CNN) Kentucky Gov. Matt Bevin recently said he chose to expose all nine of his children to the chickenpox instead of giving them the vaccine.

"They had it as children. They were miserable for a few days, and they all turned out fine," Bevin said in an interview with WKCT, a Bowling Green, Kentucky, radio station.

So-called chickenpox parties, in which parents expose their kids to the disease based on the belief that it will be more serious if contracted as an adult, are not a new concept. Before vaccines became available, the parties used to be very popular for diseases such as chickenpox or measles.

Although these parties are far less common now, parents will still occasionally advertise having a child with chickenpox at home, inviting other parents with small children to come "get it over it and develop lifelong immunity."

Are chickenpox parties a good idea?

No, they really are not a good idea at all.

Chickenpox parties were an OK idea in the days when parents had no other way to build long-lasting immunity in their children. But since the introduction of the chickenpox vaccine in 1995, parents no longer need to go to these extremes. They have a much safer way to make sure their kids are protected for years to come.

Two doses of the vaccine, given at ages 12 months through 15 months and then again at 4 through 6 years, are about 90% effective at preventing chickenpox.

In the small number of people who still get chickenpox despite having received the vaccine, the illness is usually milder, with fewer or no blisters and a mild fever, or sometimes no fever at all, according to the US Centers for Disease Control and Prevention.

Isn't 'natural immunity' to diseases like chickenpox better than 'vaccine immunity'?

Developing immunity to an infectious disease like the chickenpox means the immune system has seen the virus, has mounted a response, and has developed what's called "memory" to the particular illness. This immune system memory will allow it to react faster the next time it encounters a virus like the chickenpox, protecting the person against the infection.

The immune system does not care how the body was exposed to the illness. Whether this happened through one full blown infection such as that acquired at a chickenpox party, or after several doses of a vaccine, immunity is immunity.

In the long run, the difference comes in days feeling "miserable," like Bevin admitted his children felt; in days missed from school and work; and in the small but very real number of severe and potentially fatal complications that come from acquiring an illness like the chickenpox.

What's the big deal? I got chickenpox when I was a kid

Many of us did. Again, our parents had no better way to protect us against the chickenpox, and it is true that the illness can be more severe in adulthood.

But although many still think of the chickenpox as a mild, no-big-deal childhood illness, the truth is that this very contagious infectious disease can go beyond the rash, itchiness and fever.

Before the vaccine was introduced in the United States in 1995, chickenpox used to affect 4 million people every year. Among those, 8,000 to 18,000 were hospitalized, and 100 to 150 died every year. In 2017, the number of total cases was down to 8,775, according to the CDC

Get CNN Health's weekly newsletter Sign up here to get The Results Are In with Dr. Sanjay Gupta every Tuesday from the CNN Health team.

Chickenpox can be more serious in pregnant women and children under age 1. The vaccine is not indicated for either of these groups, hence the importance of everyone else being vaccinated and stopping the spread of this illness.

The CDC also explains that complications from the chickenpox include bacterial superinfections of the skin, blisters, pneumonia, and extension of the infection to the central nervous system -- in addition to hospitalization and death.

Can you get shingles if you had the chickenpox vaccine?

The short answer to the shingles question is this: All evidence so far indicates that those who receive the chickenpox vaccine have a lower risk of developing shingles later in life than those who had the chickenpox itself.

Shingles, also known as herpes zoster, is a skin disorder triggered by the chickenpox or varicella virus. It can remain dormant along nerve roots after someone gets the chickenpox and reactivate later in life.

Vaccination against shingles is recommended for all adults 50 and older in the United States.