COVID-19: Antibodies and Immunity

What is the difference between molecular diagnostic methods and serological studies?

Molecular diagnostics”, including polymerase chain reaction (PCR) testing, detects the genetic material of the virus and thus allows you to determine whether a person is currently infected with the SARS-CoV-2 virus. “Serologic testing” detects antibodies against the virus by measuring the amount of antibodies produced after infection, which allows you to establish whether a person has previously been infected with SARS-CoV-2. Serologic tests should not be used to diagnose acute SARS-CoV-2 infection as antibodies are produced several weeks after infection.

What are the results of seroprevalence studies published to date?

Some studies in areas with confirmed high prevalence of the virus, as well as studies by medical professionals in these areas, estimated the infection rate a second time to be above 20%.

Does the presence of antibodies mean that a person is immune?

Much research is currently being done to better understand the antibody response after infection with SARS-CoV-2. Several studies to date show that most people who have had SARS-CoV-2 infection develop antibodies specific for this virus. However, the levels of these antibodies may be different in patients with severe disease (higher antibody levels) and those with mild or asymptomatic disease (lower antibody levels). Much research is currently being done to better understand what levels of antibodies are needed for protection and how long these antibodies last in the body.