Coronavirus Antibody Test

The Online Clinic offers two different antibody tests. Both are self-collect samples with results processed in a UKAS accredited laboratory. The Online Clinic is approved by the Department of Health and Social Care as a private provider of Covid-related testing.

IgG/IgM Antibody Test

This test is a Total IgM/IgG Antibody test. You will be sent a CE marked sample collection kit specially designed to be used at home and approved by the Medicines and Healthcare Regulatory Agency. Your blood sample (from a finger prick) is then sent to our laboratory to be analysed. You will receive a copy of your lab report with an interpretation from a doctor telling you if you have the SARS-CoV-2 antibodies (indicating that you have had the Covid-19 infection). Results take 24 hours from when the sample is received at the lab. You will receive your lab report and an interpretation from a doctor as part of the service.

The test used is the Roche Total IgM/IgG assay. The test has a specificity of 100% and a sensitivity of 97.4%. This test assay is CE marked for capillary samples.

The sample is to be taken 14 days or more after the onset of symptoms or possible exposure to the virus. It is not known how long these antibodies persist following an infection.

The antigen used for this test is the Nucleocapsid. Results are reported as positive or negative for total SARS-CoV-2 antibodies. This test is not appropriate for monitoring antibody levels after vaccination.

Spike Antibody Test (Quantitative)

This test uses the same sample collection method set out above. The test is CE marked for capillary samples and has been validated by the laboratory and submitted to UKAS for accreditation.

Unlike the IgG/IgM test, the Spike Protein test provides the antibody levels, as well as an interpretation of positive or negative for SARS-CoV-2 antibodies. This test is appropriate for use to monitor response after vaccination.

The antigen used for this test is the Receptor Binding Domain (RBD) on the Spike Protein. Where a patient has been vaccinated against SARS-CoV-2 (and has no history of natural infection), the antibodies they develop are to the RBD spike antigen. With natural infection, an individual may have detectable antibodies to both the Nucleocapsid antigen and the RBD antigen.

The Spike Protein Antibody test has a sensitivity of 99.98% and a specificity of 98.8%.

Do not take a sample earlier than 14 days after vaccination. Our recommendation is that you wait until at least 35 days after your first vaccination, as most patients will have detectable antibodies at this point.

Please note that not everyone will develop an antibody response to an infection or vaccination.

For more information about Covid-19 or for the RNA PCR swab, please visit our coronavirus test page.

Reviewed by: Dr Loraine Haslam MBBS, DRCOG, DFSRH, LoC SDI, LoC IUT, MRCGP
GMC registration number: 4524038
Date: 27 March 2025
Next review: 26 March 2027
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The Medical Register at the GMC website.