How do kids get it? By being near an infected person. Whether they inhale a sneezed droplet by a sick child in the grocery store or share milk with another sickie at school, chicken pox are easily spread through direct contact, airborne particles, or infected droplets from a sneeze or cough. It can take anywhere between 10 and 21 days to show symptoms after being infected. And a child becomes contagious a day or two before any spots appear.

Is it dangerous? "The older you are [when you get the disease], the more severe the chicken pox are," says Dr. Myron Levin, Professor of pediatrics and medicine at the University of Colorado at Denver Health Sciences Center. Teenagers are more likely to have higher fevers, more lesions and possible damage to their organs (i.e. the liver), he explains. Adults can even develop pneumonia.

For those of all ages, "the most frequent complication …is that the pox themselves, the skin lesions, would become infected with bacteria," says Baltimore. But this is very rare. If infection was to happen it could, in severe cases, lead to serious illnesses such as streptococcus (which can cause strep throat, pneumonia or meningitis) or encephalitis (an infection of the brain). Those at high risk of serious complications include children with a compromised immune system (i.e. cancer patients or those with an immune disease).

Can you get it twice? It's extremely unlikely, say Baltimore, Levin and the CDC. Once you've had the chicken pox, you're immune to it. The disease actually remains in your body even though you have no symptoms. If you or your child had the disease before reaching six months of age, however, you are at a higher risk of reinfection later in life. And about one in 10 adults who've had the illness as children will develop shingles, a painful infection caused by the herpes zoster virus, after 50 years of age.

Preventing chicken pox. The best way to prevent the chicken pox is to have your child vaccinated, says Baltimore. "The goal of the chicken pox vaccine is to prevent the chicken pox in everyone."