Final answer:
Children should receive their first dose of the varicella vaccine at 12 to 15 months of age, which protects against chickenpox and its complications.
Step-by-step explanation:
The first dose of the varicella vaccine, commonly known as the chickenpox vaccine, is recommended to be given to children at 12 to 15 months of age, according to the United States Centers for Disease Control and Prevention (CDC). The vaccine is critical in preventing chickenpox, a virus which initially presents with a pustular rash mainly on the trunk and can become latent in the body after the first infection. Although chickenpox is often mild in children, it can lead to more severe complications if contracted later in life. Prior to the availability of the vaccine, some parents participated in "chickenpox parties" to ensure their children acquired immunity early. Today, vaccination is the safest and most effective way to prevent chickenpox and its potential complications.