COVID-19 (SARS-CoV-2) Antibody testing

Antibody testing can detect whether a person has been infected previously or has a vaccine-induced immune response.

TDL offers 4 assays for the detection of antibodies targeted against SARS-CoV-2:

• Roche Elecsys Anti-SARS-CoV-2 S (Spike) IgG/IgM Total Antibody

• Roche Elecys Anti-SARS-CoV-2 IgG/IgM Total Antibody

• Abbott Architect SARS-CoV-2 IgG

• Abbott Architect SARS-CoV-2 IgM

Testing should be undertaken 14 days or more following exposure,  onset of symptoms or post-vaccination.  The incubation period of COVID-19 ranges from between 1 to 14 days, with the majority of cases manifesting with symptoms at 3–5 days. 

If an individual has been infected with SARS-CoV-2, they may have detectable antibodies to both the nucleocapsid (N) and the spike protein receptor binding domain (RBD). Baseline antibody tests for both nucleocapsid and RBD antigens are therefore helpful to identify patients who have been previously infected with SARS-CoV-2. It is not yet known if an individual with a positive result showing presence of IgG levels following being infected with SARS-CoV-2 will be protected, either fully or partially from future infection, or for how long protective immunity may last.

If an individual has been vaccinated against SARS-CoV-2, with no history of natural infection, the antibodies they develop are to the spike protein receptor binding domain. Determining the levels of these antibodies could play a role in establishing vaccine efficacy and vaccine-induced immune response.

Roche Elecsys Anti-SARS-CoV-2-S (Spike) IgG/IgM total antibody test

This blood test enables the determination of both the presence and level of antibodies to the SARS-CoV-2 spike protein, which is the target of many COVID-19 vaccines,.  It can can signal whether a person has already been infected and has potentially developed immunity to the virus., and plays an important part in characterising a vaccine-induced immune response.

Roche Elecys Anti-SARS-CoV-2 IgG/IgM total antibody test

This blood test enables the determination of the presence  of IgG and IgM antibodies to the SARS-CoV-2 nucleocapsid protein.

Abbott Architect SARS-CoV-2 IgG test 

This blood test enables the determination of the presence  of IgG antibodies to the SARS-CoV-2 nucleocapsid protein.

Abbott Architect SARS-CoV-2 IgM test

This blood test enables the determination of the presence  of IgM antibodies to the SARS-CoV-2 spike protein.

Structure of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2).
Source: Roche 

Structure of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2).
Source: Roche 

Please note:

• Antibody tests cannot diagnose acute infection.
• Not everyone will develop an antibody response to COVID infection or vaccine.
• Timing of seroconversion following vaccine ≥ 14 days.
• Results from different manufacturers of commercial assays should not be compared
   

See also:

• COVID-19 information: Immune response
• COVID-19 information: Antibody testing