SOME INTERESTING FACTS ABOUT COVID-19 ANTIBODY TEST.
The entire world today is crippled by the Covid-19 disease caused by the corona virus. The corona virus has brought the world to its knees with worldwide lockdowns imposed like never before. Multiple tests are used to detect the infection and they include many different types of tests. These tests are used obviously for the different purpose too. Their cost too is vastly different ranging from very less to very costly. One such test nowadays famous and in use is covid-19 antibody test. Here we will discuss some interesting facts about Covid-19 antibody test.
We will discuss it in a way you will get some background idea and then we will discuss about test itself:
What is immunity?
You may already know about immunity. We are surrounded by environment. This environment contains air, water and soil. Everywhere in this environment there are micro-organisms. Micro-organisms are invisible to naked eyes but they are living being. They can be seen by microscopes.
These micro-organisms try to invade your body continuously. This invasion can be harmful for you. This invasion can cause different infectious diseases. Literally billions of micro-organisms try to attack you daily.
If there are so many attackers around you, there is need to protection for you too. This protective mechanism is in the form of immunity.
So, immunity essentially is a protective mechanism that saves you from the various infections and in turns the diseases. Even the cancer cells are also killed by immunity. So immunity is the gift of nature that you have got to fight against the diseases.
How does immunity works?
So, immunity works by protecting you from the infections and diseases. Let us see how it does this task in simple words.
Immunity has different types of cells in it. These different types of cells have been assigned different tasks. It is like an organized army which have various cadres and various tasks distributed amongst them. When those all are working in harmony that is your immunity is in perfect state it is the most effective army.
When the foreign micro-organism enters the system by the air, water or food or directly in the blood it comes in contact with various cells of your body. Among these cells that come in to contact are also the cells that have capability to recognize foreign particles or micro-organism from your own body cells. They do this job by identifying the protein signature on the cell surface they are called as antigens.
When foreign antigens are recognized the other attacker cells are alerted and called to action. These attacker cells are once active they migrate to the site where the invading micro-organism is. They fight these invading micro-organisms. Like real army has various weapons to fight in form of bullets, bombs and chemical weapons these too have various tools to fight.
They can fight the micro-organism by directly eating it or by attacking it with antibodies or chemical weapons they are equipped with. Various type of micro-organisms are silenced in various ways.
What is antibody?
In above discussion we have seen that immunity fights with different tools. One of such weapon is antibody. Antibodies are produced by antibody producing cells of immunity when the antigen is recognized by immunity. This antigen is provided to antibody producing cells. They have special capability to identify the protein structure of these foreign antigens in further details.
With this details fed to them these antibody producing cells produce the weapon fit for the particular micro-organism. The process is very complicated and precise. Earlier the immunity is able to do this process earlier the infection can be controlled. Antibodies either produced by infection or vaccination.
Further antibodies are of different types. Some are quickly produced and they reduce in concentration in some weeks. Some are produced by the immunity after 4-8 weeks of the infection and they remain in blood for the long time.
What is use of antibody?
Antibodies are used by our system to keep you alive. Lol. Apart from immune function these are used to detect whether you were infected in past.
If your blood tests positive for antibody against particular micro-organism that means you are or were infected by the particular micro-organism. By identifying the type of antibody it is also found whether the infection had occurred recently or in the remote past.
So by detecting presence of antibodies in blood it is clear that you were infected by the micro-organism and probably your immunity has fought bravely to overcome the attack by the invading micro-organism. It may indicate that you are immune to repeat infection and disease by the micro-organism.
Though it indicates immune status it is not always the facts. Some micro-organisms like HIV are not totally killed by the antibodies. So presence of HIV antibody in your blood suggests that you are infected with HIV and your immunity has bravely fighting it but this fight is inefficient to kill the invaders.
Essentially presence of antibody does suggest that you were infected but it does not suggest that you are protected from the infection.
What is Covid-19 antibody test?
As we discussed above when the micro-organism in this case a virus Corona virus when invades the system your body, it is identified by the immune system. Various mechanisms of immunity are activated to fight this infection.
One of the activated mechanisms is antibody production. Antibodies are produced against the corona virus in your body. 90 percent of those who got novel corona virus infection do not have any symptom. The immunity cures it. Antibodies are likely to be present within few days of infection.
Covid-19 antibody test detect these antibodies in the blood. It indicated you were infected by the corona virus in recent past.
What is use of Covid-19 antibody test?
Covid-19 antibody test may remain positive for prolonged period it is of no use to detect current infection.
This test has epidemiological significance. Conducted on large population this test gives idea that what percentage of population was infected by the disease. It can give idea how dangerous is the disease and what is the mortality rate.
Yet the role of antibody in fighting infection is not clear but it can suggest the proportion of population probably immune to infection.
What are drawbacks of Covid-19 antibody test?
Like all other tests following are drawbacks of Covid-19 antibody test:
· The test cannot be used for the diagnostic purpose for the individual but can be used as a epidemiological tool.
· The test may not detect current infection status of the person.
· The test is being sensitive false positives may come detected.
· In some cases even cured person does not have antibodies against Covid-19.
· Yet we do not know whether these antibodies can kill or neutralize the virus effectively or it is some different mechanism that works.
· Yet we do not know for how long these antibodies will last in the blood.
· Yet we do not know significance of these antibodies and need of vaccination with positive or negative status of antibodies.