"I was surprised she had a vaccine today to tell you the truth," her mother said after the most recent inoculation.
With more new vaccines coming on the market, there is a growing debate about whether we are over-vaccinating our children and underestimating the risks associated with so many shots.
Currently the government mandates vaccines against polio, diphtheria, pertussis, tetanus (known as DTP), type b influenza, measles, mumps and rubella. Shots to prevent chicken pox are recommended. Eighty percent of the nation's pre-school children are immunized.
Vaccines are considered one of the great medical triumphs of the 20th century, practically wiping out a series of killers in this country. Polio is expected to be eradicated worldwide within the next few years.
But vaccines also carry risks.
Mary Elizabeth Haggerty suffered a 45-minute-long seizure shortly after receiving a DTP shot when she was seventeen months old. She never recovered.
"I kept bringing her little white shoes to the hospital thinking she was going to wake up, sit up and stand up. And she never did, she never did. And that was six and a half years ago," said her mother Geri Haggerty.
DTP has been linked to rare cases of brain damage, and while it has been made safer it remains a cautionary tale about what can go wrong.
"As I hold that syringe in my hand and I give a new vaccine, I am often shaking. I don't want to be the one who causes the side effect," said Dr. Laura Popper of the Mt. Sinai Medical Center.
Popper wouldn't give her patients a new vaccine to prevent rotavirus, a disease that can cause deadly diarrhea and dehydration in infants.
"The benefit from the vaccine didn't seem to outweigh the possible risks and I didn't know what that risk was going to be. I just know that the vaccine arrived too quickly," she said.
It turned out to be a shot of reality when the CDC suspended use of the rotavirus vaccine in July because of side effects.
"No vaccine is 100 percent effective, no vaccine is 100 percent safe. But on balance, the benefits of vaccines far outweigh the risks for the vast majority of children," said Dr. Walt Orenstein of the Centers for Disease Control.
In the next century, the challenge for scientists will be to limit vaccine risks even further. The challenge for parents will be to ask questions and stay informed.