Chickenpox is very contagious. If one person has it, up to 90% of the people close to that person who are not immune will also become infected. Chickenpox can also be serious, even life-threatening, especially in babies, adolescents, adults, pregnant women and people with weakened immune systems. Before the vaccine was available, about 4 million people got chickenpox each year in the United States, over 10,500 of those people were hospitalized, and about 100-150 people died.

Two doses of the chickenpox vaccine is more than 90% effective at preventing chickenpox. When you get vaccinated, you protect yourself and others in your family and community. This protection is especially important for people who cannot get vaccinated, such as those with a weakened immune system (body’s lowered ability to fight germs and sickness), or pregnant women.