There is a mark on my left shoulder that says more about the vaccine controversy than Flea can express in words.

The mark was made with a stylus that had been dipped in Smallpox vaccine. I was about 6 months old. My pediatrician made several crisscrossing shallow cuts over my left deltoid (such as it was) while my mother held me. In three to four days a red and itchy bump developed. In the first week, the bump became a large blister, filled with pus, and began to drain. During the following week, the blister dried up and a black scab formed. I have seen a photograph of Flea with his twin sister on a blanket in our back yard, sporting matching black scabs.

The scab fell off in the third week, leaving a small scar.

In the summer, mothers often appear in my office without shoulder covering. I always check to see if they have a Smallpox vaccine scar. If they don't, I know they were born after 1972 or so. The longer I practice, the fewer such moms appear.

The reason these moms have no such scars is because Smallpox is gone. According to the CDC, the last endemic case of smallpox occurred in Somalia in 1977. On May 8, 1980, the World Health Assembly declared the world free of smallpox.

In the U.S. we stopped vaccinating the general population in 1972, but continued to vaccinate military personnel until 1990.

Smallpox is gone. In 1967 it killed more than 2 million people worldwide and today it is gone.

In a way, it is unfair to begin this series on the efficacy of vaccines with a discussion of Smallpox, the proverbial "low-hanging fruit" of pro-vaccine polemics. Polio hangs almost as low, but it's story will be told at Flea as well. The story probably won't get interesting to the anti-vax crowd until we start talking about Hepatitis B and Chicken Pox.