Serology (Blood) Test:
Serological testing has been getting a lot of attention lately, mostly because it’s being talked about as a measure for re-opening society, by identifying people who are immune to COVID-19. Serological tests work by looking for antibodies against the virus that causes COVID-19. Those antibodies are an indication that a person was exposed in the past, whether they remember getting sick or not.
There are two types of serological tests: one which looks at IgG antibodies and one which looks at IgM antibodies. IgM antibodies are your immune system’s first line of defense and are produced earlier in the infection. IgG antibodies take a while to build up and can be found in your body after the infection is over. A negative serological test doesn’t necessarily mean you aren’t infected. It takes a while to build both types of antibodies, so in an acute case, you wouldn’t detect them, and have a false sense of security.
Serology tests a possible indication of immunity
The big conversation surrounding serological testing is the idea that a person who tests positive is immune to COVID-19. In theory, this would mean that a healthcare worker could safely care for COVID-19 patients, essential workers could be cleared to go back to work, and others might be able to come out of quarantine or isolation.
As hopeful as this idea sounds, it may not be that simple. There’s a lot we don’t know yet, some of the unknowns include whether a person can get re-infected with COVID-19 as well as how long this immunity lasts.
If you do test positive for antibodies, don’t think this means you can go back to your normal life just yet.
If you’ve heard about the test where they stick a swab in your nose and reach it all the way to the back, that’s a diagnostic test, which works by looking for the virus itself. There are a number of diagnostic tests that have been developed, all of which work by looking for genetic material from the virus.
A positive result means the virus was detected in the patient, which indicates an active infection. Viral particles are found in a patient when they are showing symptoms, as well as for a brief period before and after, during what is known as viral shedding.
But if you’ve been tested for COVID-19, and got a negative result, that does not necessarily mean you aren’t infected.
The major issue is often poor quality samples.
Due to the new Covid-19 social distance regulations required by the government, we are currently carrying out tests on Saturday and Sunday in Bank, London from 9am -6pm