The most common complication is bacterial infection of the skin or other parts of the body, including the bones, lungs, joints, and blood. The virus can also lead to pneumonia or infection of the brain. These complications are rare but serious. Complications are more common in infants, adults, and people with weakened immune systems.
Chickenpox poses a significant threat to immunocompromised people. The best way to prevent infection in each patient is by immunizing susceptible family members and close contacts of the person.