The chicken pox vaccine not only protects the child who was vaccinated, it also protects infants who come into contact with the child afterward, according to a new study.

Prior to 1995, when the chickenpox vaccine was made available to children 12 months and older, younger infants were four times more likely to die from the infection. However, new research has shown that between 1995 and 2008, infant chickenpox cases dropped nearly 90 percent.

“Many people think of chickenpox as being a completely benign disease, but it’s not,” said Dr. Elaine Schulte, a pediatrician at the Cleveland Clinic Children’s Hospital, who was not involved in the study. "One-hundred kids died of chickenpox last year and typically that’s because they get pneumonia or they get a secondary skin infection with a bacteria. And they can get very, very sick.”

Researchers said the chickenpox vaccine provides indirect benefits for children younger than 12 months.

For instance, an older child can still potentially contract chickenpox after being vaccinated, but it's still much safer for a baby brother or sister, according to Schulte.

“It’s not impossible for kids to have chickenpox after they’ve been vaccinated, even if they have two doses of vaccine,” Schulte said. “But the case is so mild and benign that it’s much, much better.”

The study was published in the journal Pediatrics.