Anti-body test private labs

Subject: Science and tech

Context:

Some private labs in Delhi have started antibody testing for Covid-19, used to assess if a person has contracted the infection or not. The blood test is available in most top private labs and hospitals, and does not require a medical prescription.

Concept:

• Antibody test is to determine sero-prevalence in a population.
• This is not a diagnostic test, it mainly helps to check if a person has developed immunity (antibodies) to the disease.
• It will also give an indication of the infection load and recovery rate in a community.
• During the test, a blood sample is collected to determine if a person is infected with the novel coronavirus.
• Antibody tests may not be useful as ‘immunity passports’ because there is lack of clarity on the long-term immune responses of the body to the virus SARS-CoV-2.
• Enzyme Linked Immunosorbent Assay (ELISA) or Chemiluminescence Immunoassay (CLIA) test measure Covid-19-specific antibodies — Immunoglobulin G and Immunoglobulin M — which indicate that the person undergoing the test may have been infected but has since recovered.
• If a person tests positive for IgM, it indicates he/she has an active infection. In such cases, they go for a diagnostic test.
• If a person tests positive for IgG, it means they have developed immunity. If a good number of people test positive for the antibody test, it means the city is on the correct path