Reinfections and COVID-19

Reinfection with the virus that causes COVID-19 means a person was infected, recovered, and then later became infected again. After recovering from COVID-19, most individuals will have some protection from repeat infections. However, reinfections do occur after COVID-19. We are still learning more about these reinfections. Ongoing studies of COVID-19 are helping us understand:

• How often reinfections occur
• Who is at higher risk of reinfection
• How soon reinfections take place after a previous infection
• The severity (how serious the infection is) of reinfections compared with initial (the first) infections
• The risk of transmission to others after reinfection

What CDC is doing

CDC continues to work to better understand reinfections with COVID-19 to inform public health action. CDC is using a range of data sources to assess how often reinfections occur, who is most at risk for reinfection, and the risk of reinfection when there is community spread of Omicron or other virus variants. CDC has worked closely with public health jurisdictions and the Council of State and Territorial Epidemiologistsexternal icon (CSTE) to help states to count repeat infections in the same individuals over time.

An updated national surveillance case definition of COVID-19 was introduced on September 1, 2021, and includes criteria for counting new infections (reinfections) after previous probable or confirmed infections. CDC is working with multiple public health jurisdictions that are identifying reinfections to collect and analyze the data. CDC is publishing several analyses that use datasets from various sources, including cohort studies (which follow the same people over time):

• COVID-19 Cases and Hospitalizations by COVID-19 Vaccination Status and Previous COVID-19 Diagnosis — California and New York, May–November 2021
• Laboratory-Confirmed COVID-19 Among Adults Hospitalized with COVID-19–Like Illness with Infection-Induced or mRNA Vaccine-Induced SARS-CoV-2 Immunity — Nine States, January–September 2021
• Reinfection with SARS-CoV-2 among previously infected healthcare personnel and first respondersexternal icon
• Suspected SARS-CoV-2 Reinfections: Incidence, Predictors, and Healthcare Use among Patients at 238 U.S. Healthcare Facilities, June 1, 2020- February 28, 2021.external icon
• Duration of Viral Nucleic Acid Shedding and Early Reinfection With Severe Respiratory Syndrome Coronavirus 2 in Healthcare Workers and First Respondersexternal icon
• Reduced Risk of Reinfection with SARS-CoV-2 After COVID-19 Vaccination — Kentucky, May–June 2021
• Science Brief: SARS-CoV-2 Infection-induced and Vaccine-induced Immunity

How to Protect Yourself and Others

• Get a COVID-19 vaccine as soon as you can. Find a vaccine here. Everyone 12 years and older should get a booster shot when eligible.
• Consistently and correctly wear a well-fitting mask that covers your nose and mouth to help protect yourself and others.
• Stay 6 feet apart from others.
• Avoid crowds and poorly ventilated indoor spaces.
• Know when to test to be informed and prevent spread to others.
• Wash your hands often with soap and water and dry thoroughly. Use hand sanitizer with at least 60% alcohol if soap and water aren’t available.