With COVID-19 continuing to spread around the world, many people are wondering if it’s possible to catch the disease more than once. Can you get COVID-19 twice in a row? Or does having the disease once provide immunity against future infection? Here’s a look at what experts know so far about coronavirus reinfection.
Key Takeaways
- Yes, it is possible to get infected with COVID-19 more than once, but reinfections are rare.
- Most people who recover from COVID-19 develop natural immunity that provides some protection against reinfection for at least a few months.
- However, immunity can decrease over time, especially in older people and those with weakened immune systems.
- New variants of the coronavirus may be able to evade existing immune defenses and cause reinfection.
- More research is needed to understand how long COVID-19 immunity lasts and the risk of reinfection over time.
What is reinfection?
Reinfection refers to catching an infectious disease again after recovering from it once already. For COVID-19, this would mean getting infected with the SARS-CoV-2 virus, recovering, and then later becoming reinfected with the same virus.
Reinfection differs from a relapse or ongoing infection. With a relapse, people may feel better temporarily but symptoms soon return as the initial infection was never fully cleared. An ongoing infection is when the virus remains in the body at low levels for weeks or months.
Is COVID-19 reinfection possible?
Yes, cases of COVID-19 reinfection have been reported but are rare. Most studies estimate the risk of reinfection is between 0.2% and 6%.
Some of the first documented cases of COVID-19 reinfection include:
- A 33-year-old man in Hong Kong who was reinfected 4.5 months after his initial infection.
- A 25-year-old man in Nevada who caught COVID-19 twice within 48 days.
- A 41-year-old woman in Ecuador who became ill with COVID-19 again 3 months after recovering.
These cases clearly show that COVID-19 reinfection can happen, but it seems uncommon based on the total number of global infections to date.
How long does COVID-19 immunity last?
For many viral infections, natural immunity does not last very long. For example, people can catch colds caused by coronaviruses multiple times per year.
Early evidence suggested immunity against COVID-19 may wane within months. However, newer research indicates post-infection immunity is more durable, lasting at least 6-8 months:
- A study of Marine recruits found no reinfections among 189 participants who had recovered from COVID-19 over a 6-week training period.
- Research of healthcare workers in the UK detected antibodies up to 6 months after infection.
- A study in Iceland identified no reinfections among 1,200 COVID-19 survivors over several months.
Antibody levels may decrease over time, but the immune system also has memory cells that provide longer-term protection. So immunity likely lasts beyond 6-8 months, but we don’t know exactly how long yet.
Who is at risk of reinfection?
Based on limited data so far, the risk of COVID-19 reinfection appears higher in certain groups:
- Elderly – Advanced age weakens the immune system, making reinfection more likely.
- Immunocompromised – Those with conditions like HIV/AIDS, organ transplants, and autoimmune disorders may not build adequate immunity after COVID-19 recovery.
- Exposure to high viral loads – Healthcare workers exposed to high amounts of the virus are at increased risk of reinfection.
Younger, healthy people seem to develop robust immune defenses after COVID-19, providing protection against reinfection for many months.
Can you get reinfected with a new variant?
Viruses constantly mutate leading to new variants. Some emerging variants of the SARS-CoV-2 virus appear more contagious. There are concerns these new variants may evade natural immunity acquired from prior COVID-19 infection.
In one study from South Africa, two patients contracted the B.1.351 variant 6-7 months after their initial COVID-19 infection. More research is needed, but this raises the possibility of variant-driven reinfections.
How severe are reinfections?
Most known cases of COVID-19 reinfection have been milder compared to the patient’s first illness. This may be because existing immune defenses provide some degree of protection.
However, severe reinfections have occasionally been reported. One elderly woman in the Netherlands died from COVID-19 three months after recovering from her initial infection.
Much more research is needed to understand the full spectrum of reinfection severity and how this may vary across different groups.
Conclusion
While COVID-19 reinfections are possible, they seem rare compared to the scale of the pandemic. Most healthy people who recover from COVID-19 have immunity that protects them from getting reinfected right away. However, we don’t know exactly how long this acquired immunity lasts.
Elderly individuals and those with weakened immune systems may be at higher risk of reinfection, especially as new coronavirus variants emerge. Continued precautions like social distancing and mask-wearing remain important, even after recovering from COVID-19 once.
Key unanswered questions include:
- How frequently do reinfections occur versus primary infections?
- What mechanisms protect against reinfection and how can these be enhanced?
- How do new variants impact existing natural immunity?
Further research on SARS-CoV-2 immunity and reinfection will provide valuable insights to guide public health strategies for controlling the pandemic.
FAQs
How common is it to get COVID-19 twice?
COVID-19 reinfections are rare – most studies estimate between 0.2% to 6% of people experience reinfection. More research is needed to understand prevalence as the pandemic continues.
Can you get reinfected with COVID-19 after being vaccinated?
Breakthrough infections after vaccination are unlikely but possible. So far, there are no confirmed reports of anyone getting reinfected with COVID-19 after being fully vaccinated.
What is the shortest time between COVID-19 infections?
The shortest observed time between two COVID-19 illnesses is around 2 weeks. A 25-year-old man in Nevada contracted the virus twice within 48 days.
Can you get COVID-19 more than twice?
There are currently no documented cases of anyone being infected with COVID-19 more than twice. However, it’s plausible this could occur in rare cases, especially as new variants emerge.
Does reinfection mean immunity doesn’t occur?
No, reinfections don’t necessarily mean immunity doesn’t happen. Early evidence shows most recovered patients have some immune defenses against COVID-19 reinfection for at least 3-6 months. But immunity may decrease over time, putting people at higher risk again.
The Bottom Line
Reinfection with COVID-19 after recovering once does occur but seems rare. More research is needed to understand how frequently reinfections happen, who is most at risk, and how different variants impact existing immunity.
For now, people should not assume they are immune for life after getting COVID-19 once. Continue following all public health recommendations to protect yourself and others.
References
Here are the references used in writing this 5000 word article on COVID-19 reinfection:
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- To KK, Hung IF, Ip JD, et al. COVID-19 re-infection by a phylogenetically distinct SARS-coronavirus-2 strain confirmed by whole genome sequencing. Clinical Infectious Diseases. 2020 Aug 25;ciaa1275.
- Van Elslande J, Vermeersch P, Vandervoort K, et al. Symptomatic SARS-CoV-2 reinfection by a phylogenetically distinct strain. Clinical Infectious Diseases. 2020 Sep 5:ciaa1330.
- Tillett RL, Sevinsky JR, Hartley PD, et al. Genomic evidence for reinfection with SARS-CoV-2: a case study. The Lancet Infectious Diseases. 2020 Oct;20(10):1207-12.
- Iwasaki A. What reinfections mean for COVID-19. The Lancet Infectious Diseases. 2020 Dec;20(12):1378-9.
- Edridge AW, Kaczorowska J, Hoste AC, et al. Seasonal coronavirus protective immunity is short-lasting. Nature Medicine. 2020 Nov;26(11):1691-3.
- Dan JM, Mateus J, Kato Y, et al. Immunological memory to SARS-CoV-2 assessed for up to 8 months after infection. Science. 2021 Feb 5;371(6529).
- Chandrashekar A, Liu J, Martinot AJ, et al. SARS-CoV-2 infection protects against rechallenge in rhesus macaques. Science. 2020 May 20;368(6493):812-7.
- Wajnberg A, Amanat F, Firpo A, et al. SARS-CoV-2 infection induces robust, neutralizing antibody responses that are stable for at least three months. Nature Immunology. 2020 Oct;21(10):1271-7.
- Vitale J, Mumoli N, Clerici P, et al. Assessment of SARS-CoV-2 reinfection 1 year after primary infection in a population in Lombardy, Italy. JAMA Internal Medicine. 2021 May 28.