In early September, the Kansas City Royals were leading their baseball division. Then a pox landed on their clubhouse — chickenpox, that is.

Star relief pitcher Kelvin Herrera and right fielder Alex Rios came down with the disease. They're from the Dominican Republic and Puerto Rico, respectively, where vaccines — and chickenpox as a childhood disease — are not common.

In this country, where the chickenpox vaccine was added to the childhood immunization schedule in 1995 (the booster in 2006), chickenpox is pretty rare.

But chickenpox is a highly contagious disease, and players come in constant contact with other players, coaches, reporters and fans who may be immune because they've had the disease or been inoculated.

When an adult gets the chickenpox, severe complications can follow, including bacterial infections of the skin, soft tissues, bones, joints, or bloodstream; pneumonia; toxic shock syndrome; Reye's syndrome, if you're taking aspirin; and encephalitis (dysfunction of the brain often follows, as does a decrease in coordination).

Dr. Steven Gordon, chairman of the department of infectious diseases at the Cleveland Clinic, told CBS News that chickenpox "can be more severe in adults, but it's especially a concern for pregnant women. The fatality rate can be quite high."

So if you or anyone in your family isn't immune to chickenpox, don't be a Royal nincompoop. Get inoculated ASAP.

If you catch chickenpox, the best case scenario is itchy blisters all over your body, and you miss two weeks of work. Worst case? Dr. Gordon just told you.