Duration of COVID-19 Antibodies
COVID-19 antibodies remain detectable for at least 120 days (4 months) for IgG antibodies and at least 152 days (5 months) for neutralizing antibodies after infection, though levels decline over time and protection against reinfection remains uncertain. 1
Antibody Development Timeline
- Nearly all patients (>90%) develop IgG antibodies after SARS-CoV-2 infection (moderate certainty of evidence) 1
- Most patients develop IgM antibodies (moderate certainty) and IgA antibodies (low certainty) 1
- Nearly all patients develop neutralizing antibodies (low certainty) 1
- Antibody levels typically peak at specific timeframes after symptom onset or PCR diagnosis:
Antibody Persistence
- IgG antibodies probably remain detectable for at least 120 days (4 months) after infection (moderate certainty) 1
- Neutralizing antibodies may remain detectable for at least 152 days (5 months) after infection (low certainty) 1
- More recent research suggests antibodies can persist longer:
- Some studies show IgG antibodies can last for at least 12 months after infection, though titers decrease significantly in the first 6 months and then stabilize 2
- Approximately 90% of patients still have detectable IgG antibodies against spike and nucleocapsid proteins and neutralizing antibodies against pseudovirus at around 1 year post-infection 3
- SARS-CoV-2-specific memory B and T cells have been detected in the majority of patients up to 15 months after infection 4
Factors Affecting Antibody Response
- Disease severity: More severe COVID-19 illness may be associated with a more robust antibody response in terms of antibody levels (low certainty) 1
- Presence of symptoms: Symptomatic infection may be associated with higher antibody prevalence and levels compared to asymptomatic infection (low certainty) 1
- Age: Older age may be associated with higher antibody levels (low certainty) 1
- Race/ethnicity: Non-White race may be associated with higher antibody prevalence and levels (low certainty) 1
Antibody Decline Pattern
- After the initial peak, neutralizing antibody titers typically decline over time, following the pattern of an acute viral infection 5
- The magnitude of the peak antibody response is dependent on disease severity, with higher peaks generally seen in more severe cases 5
- Some individuals with high peak neutralizing antibody titers maintain high levels beyond 60 days, while others with lower peak titers may approach baseline levels within the follow-up period 5
Clinical Implications
- Current evidence is uncertain regarding the presence, level, or durability of natural immunity conferred by SARS-CoV-2 antibodies against reinfection 1
- PCR tests may remain positive for up to 30 days in some patients, well after they are no longer infectious 6
- For clinical purposes, recovery is typically defined as at least 3 days without fever, improvement in respiratory symptoms, and at least 10 days since symptoms first appeared 6
- Antibody testing is not recommended to guide the reinitiation of treatments in patients with rheumatic diseases after COVID-19 1
Important Caveats
- The presence of antibodies does not necessarily equate to protection against reinfection 1
- Research gaps remain regarding the degree of protection conferred by antibodies against reinfection and how long this protection may last 1
- Antibody response may vary based on individual factors such as age, sex, race/ethnicity, comorbidities, and disease severity 1
- Newer variants of concern may partially escape the neutralizing activity of antibodies developed against earlier strains 4
- Vaccination will affect the development of SARS-CoV-2 antibodies, and interpretation of antibody tests in vaccinated individuals requires different considerations 1