Chickenpox Facts and Statistics: What You Need to Know

Chickenpox (varicella) is a very contagious viral infection. It causes an itchy rash that eventually spreads all over the body. Chickenpox is more common in children than adults.

However, according to the Centers for Disease Control and Prevention (CDC), chickenpox is far less common than it used to be. This is largely thanks to the varicella vaccine, introduced in 1996. It helps prevent more than 3.5 million cases of the contagious disease each year in the United States.

This article provides an overview of chickenpox facts, including statistics on chickenpox by gender, ethnicity, and more. 

Child with chickenpox on face

Goldcastle7 / Getty Images

What Is Chickenpox?

Chickenpox is caused by the varicella-zoster virus (VZV) and is highly transmissible. It causes a very itchy, blister-like rash. The blisters burst and crust over. It can cause serious complications, especially in people with weakened immune systems.

Once a person has chickenpox, the virus remains in their body and can reactivate years later to produce shingles (herpes zoster). Nowadays, chickenpox is preventable, thanks to available vaccines.

How Common Is Chickenpox?

Before the chickenpox vaccine was introduced, more than 4 million people contracted the disease each year in the United States. Nowadays, far fewer people get chickenpox. The CDC estimates that fewer than 350,000 people get it yearly in the United States.

Additionally, 9 in 10 U.S. adults are immune to the disease because they had chickenpox as children.

Incidence rates vary by state and year but still remain lower than before. However, case rates tend to be higher in infants because they can’t receive vaccines until they are over 1 year old.

For example, in Florida in 2022, infants had the highest chickenpox rates compared to other age groups, around 1.7 cases per 100,000. But the rate is still very low compared to when the vaccine didn’t exist.

Compared to the mid-1990s before the vaccine, rates reported by several states from 2013 to 2014 show that chickenpox prevalence has decreased by 97%.

Chickenpox by Ethnicity 

Chickenpox can affect anyone, regardless of race or ethnicity. Data collected by the Louisiana Office of Public Health suggests that chickenpox rates are slightly higher in White populations compared to Black populations.

According to 2017 data, chickenpox vaccination rates in children between the ages of 19 and 35 months are about the same for Black, Hispanic, American Indian/Alaskan Native, and White populations in the United States.

Chickenpox by Age and Gender

People of any sex tend to contract chickenpox equally. Before the vaccine, chickenpox affected all age groups but was particularly common in children age 1 to 4.

Since the introduction of the chickenpox vaccine, cases have decreased for all age groups, even for infants who can’t yet get the vaccine. Because other people are protected and less likely to transmit the disease, infants are also unlikely to contract it.

However, because they have no protection, infants and anyone else who has never received the chickenpox vaccine are the most likely to contract the disease if exposed to the virus. 

Causes of Chickenpox and Risk Factors 

Chickenpox is caused by the varicella-zoster virus (VZV). You can contract it through close contact with someone who has chickenpox or shingles, which is a condition caused by reactivation of the virus. They don’t need to have a rash to transmit the disease, though. Someone can be contagious one to two days before showing symptoms.

Before the vaccine was common, being a child was a risk factor for contracting chickenpox. But with the introduction of vaccines, the disease is much less common in all age groups.

You have a higher risk of contracting chickenpox if you:

  • Have never been vaccinated for chickenpox
  • Have never had chickenpox 

What Are the Mortality Rates for Chickenpox? 

Death rates from chickenpox have decreased significantly since the mid-1990s. Back then, over 100 deaths per year could be attributed to chickenpox. The number of chickenpox–related deaths in the United States is now less than 20 yearly.

Severe complications of chickenpox include viral pneumonia (lung inflammation), encephalitis (brain inflammation), and hemorrhagic (bleeding) conditions. People who are at higher risk for complications or death from chickenpox include:

  • Adults
  • Pregnant people
  • Infants
  • People with weakened immune systems

Vaccination can dramatically reduce your chances of contracting chickenpox and protect you from complications.

A shingles vaccine is also available for people who have had chickenpox. The Shingrix vaccine is recommended for most people age 50 and older. It helps reduce the incidence of shingles and its associated complications.

Screening and Early Detection

There is no recommended screening for chickenpox. Healthcare providers can usually diagnose it based on the rash and other symptoms. As it is highly contagious, a healthcare provider may provide instructions so as not to expose other people (such as not entering a shared waiting room).

Treatment for chickenpox is usually to relieve the symptoms. The itching can be intense, and scratching can lead to bacterial skin infections. In people at high risk for severe complications, antiviral medications or varicella-zoster immune globulin may be given.

Summary

Chickenpox is a highly contagious disease. While it used to be common in children, the introduction of the chickenpox vaccine has significantly reduced chickenpox cases in the United States. 

Most people are immune to chickenpox because of prior infection or vaccination, so they are less likely to transmit the disease to vulnerable people, including infants and people with weakened immune systems. 

11 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. About chickenpox

  2. Centers for Disease Control and Prevention. Chickenpox vaccine saves lives and prevents serious illness infographic.

  3. Immunization Action Coalition. Varicella (chickenpox): questions and answers

  4. Florida Health. Varicella surveillance.

  5. Centers for Disease Control and Prevention. Chapter 22: varicella

  6. Louisiana Office of Public Health. Varicella annual report 2017

  7. Centers for Disease Control and Prevention. Supplementary table 1. Estimated vaccination coverage among children aged 19–35 months, by selected vaccines and doses, race/ethnicity,* and poverty level† — National Immunization Survey-Child, United States, 2017§ : for vaccination coverage among children aged 19–35 months — United States, 2017.

  8. Centers for Disease Control and Prevention. Transmission.

  9. Centers for Disease Control and Prevention. Chickenpox (varicella) for healthcare professionals.

  10. Centers for Disease Control and Prevention (CDC). Complications.

  11. Centers for Disease Control and Prevention. What everyone should know about the shingles vaccine (Shingrix).

By Steph Coelho
Steph Coelho is a freelance health writer, web producer, and editor based in Montreal. She specializes in covering general wellness and chronic illness.