Getting vaccinated is the best way to prevent chickenpox. Currently, two doses of vaccine are recommended for children, adolescents, and adults. While no vaccine is 100% effective in preventing disease, the chickenpox vaccine is very effective: about 8 to 9 out of every 10 people who are vaccinated are completely protected from chickenpox. In addition, the vaccine almost always prevents severe disease. If a vaccinated person does get chickenpox, it is usually a very mild case lasting only a few days and involving fewer skin blisters (usually less than 50), mild or no fever, and few other symptoms.