Immunity in COVID-19 infected people may not last more than two years

Immunity in COVID-19 infected people may not last more than two years

Last Reviewed : 12/23/2020
Immunity in COVID-19 infected people may not last more than two years

In most of the viral illnesses, infected people develop immunity against the infection. Physiologically, human bodies have the ability to develop antibodies against viruses. Depending on the virus, these antibodies may last for few months to several years. Chicken pox virus can mount antibodies that last for the rest of our life. If you get infected as a kid, you develop life long immunity against chicken pox. With whooping cough infection, immunity may last up to 20 years. With swine flu, H1N1 influenza, immunity is expected up to 10 years. With common cold, immunity may last long enough as there are hundreds of virus strains that can cause infection.

As more and more people are affected by COVID-19, it is no surprise everyone would like to know how long does the immunity last to SARS-CoV-2 virus. As COVID-19 infection was first identified only a few months ago, nobody exactly knows how long the immunity will last in the infected people. As Novel Coronavirus or SARS-CoV-2 virus has close similarities to SARS-CoV virus, we may have to assume that the antibodies mounted by SARS-CoV-2 virus may be similar to its close cousin SARS-CoV virus.

In a study published in Emerging Infectious Diseases, 176 patients were included who were affected by SARS coronavirus. SARS specific antibodies were identified an average of 2 years from the onset of infection. Immunity dropped significantly during the third year after infection. The study concluded that SARS infected people are prone to reinfection during or after the third year of SARS coronavirus infection. Another coronavirus, MERS infection also mounts immunity that typically lasts slightly below two years.

Based on the available studies, we can presume that immunity to Novel Coronavirus may not last very long. People infected by COVID-19 may have immunity up to two years and may be prone to reinfection after that period. Hopefully, if vaccine is available by then, it may help to boost immunity in both infected and non-infected people.



  1. Li-Ping Wu et al. Duration of Antibody Responses after Severe Acute Respiratory Syndrome. Emerg Infect Dis. 2007 Oct; 13(10): 1562–1564. doi: 10.3201/eid1310.070576
  2. Chang SC et al. Longitudinal analysis of severe acute respiratory syndrome (SARS) coronavirus-specific antibody in SARS patients. Clin Diagn Lab Immunol 2005;12:1455–7

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