Surveillance

Trends in Chickenpox (Varicella) and Impact of Chickenpox Vaccination

Chickenpox (varicella) used to be very common in the United States before the chickenpox vaccine became available in 1995. About 4 million people would get chickenpox each year. Also, there were about 10,500-13,000 hospitalizations and 100 to 150 deaths from chickenpox each year. Most of the severe complications and deaths from chickenpox occurred in people who were previously healthy.

In 2010, 90% of children 19–35 months old in the United States had received one dose of varicella vaccine. Among adolescents 13 to 17 years who were eligible for chickenpox vaccine, 58% had received two doses.

Thanks to the chickenpox vaccine, this disease as well as hospitalizations and deaths from chickenpox have gone down dramatically in the United States. In four states that consistently reported chickenpox to a national surveillance system, chickenpox rates in 2009 were 41 to 81 percent lower than the years before the vaccine. From 2000 to 2006, fewer hospitalizations—71 percent less—occurred from chickenpox than the years before the vaccine.

Deaths from chickenpox have gone down in all age groups. From 2005 to 2007, compared with 1990 to 1994 (before the chickenpox vaccine was introduced), chickenpox deaths in children and adolescents less than 20 years old went down 97%. In adults 20-49 years old, deaths went down 90%.

Resources for Public Health Officials and Health Care Professionals

Chickenpox cases and deaths should be reported to the National Diseases Surveillance System.

For information on trends in varicella surveillance, guidance on conducting surveillance and resources, see Conducting Varicella Surveillance.

• Chapter on Varicella, Manual for the Surveillance of Vaccine-Preventable Diseases
• Surveillance worksheets
  • Varicella Surveillance Worksheet [282 KB, 3 pages]
  • Varicella Death Investigation Worksheet [169 KB, 4 pages]
  • Varicella Outbreak Reporting Worksheet [150 KB, 1 page]