There is suddenly a lot of chatter about antibody tests among those getting the Covid-19 vaccine, both on social media and off it.
With multiple reports doing the rounds over the efficacy of Covid-19 vaccines, people are anxious to find out whether the shot they are taking is giving them protection against the novel coronavirus or not.
This is where an antibody test comes in.
WHAT IS ANTIBODY?
An antibody is a protein that fights off invaders (read viruses, bacteria and other disease-causing particles) in the body. Antibodies are essential to our immunity. Every invader is countered by a different set of antibodies.
The presence of enough antibodies against a particular virus or bacteria means guaranteed protection against the consequent disease. Covid-19 became a pandemic because SARS-CoV-2, the coronavirus that causes this disease, was an unknown invader.
HOW SARS-CoV-2 GOT PAST ANTIBODY SHIELD
Humans did not have antibodies to fight off SARS-CoV-2 in their immune systems. Most still don’t have. Of over 700 crore people, only about 13.25 crore have got the novel coronavirus infections. In India, 1.25 crore have got this infection – out of about 137 crore people.
An infection triggers the manufacturing of antibodies in the human body for a particular invading virus, bacteria or other pathogen. So, an overwhelming majority of people still don’t have an immune system that is ready to fight off SARS-CoV-2.
This is why they all need to remember the old adage: “Prevention is better than cure”. Wearing a face, proper hand sanitation and maintaining physical-social distancing forms Covid-19 prevention protocol.
VACCINES AND ANTIBODIES
There is, however, another way to build antibodies against a particular disease. This involves taking a vaccine dose. Vaccines prime the immune system for a fight against a potential invader. Vaccination sets the stage for a situation where if and when a pathogen attacks the body, the immune response would be swift and adequate.
Both the vaccines approved in India – Covishield, the AstraZeneca shot, and Covaxin, the ICMR-Bharat Biotech jab – have shown good efficacy during trials. But many people want confirmation of whether the vaccine is triggering an adequate immune response against Covid-19.
The worry over immune response is accentuated also by the detection of several mutant variants including a double-mutant version in India and other parts of the world. SARS-CoV-2 variants are travelling fast across the globe with humans. The rise in Covid-19 cases along with mutant variants has sparked off the quest for an antibody test.
WHAT AN ANTIBODY TEST DOES
An antibody test can ascertain whether a person has enough antibodies in her immune system to fight off the invading coronavirus. The test checks for the presence of antibodies by examining blood samples. Antibody tests are also known as serology tests. You might have heard about sero-surveys undertaken by government agencies in the wake of the Covid-19 spread across the country.
The antibody test does not check the virus’s presence in the body but only of the fighter protein. If the specific antibodies are present in the blood, it means the immune system is ready to identify the virus and fight it off.
For people who have not been infected by SARS-CoV-2 and have taken a Covid-19 vaccine, an antibody test can be an indicator of much she is prepared to beat the coronavirus infection.
SHOULD YOU GO FOR ANTIBODY TEST?
Recent studies have shown that if the gap between the two doses of Covid-19 vaccine is increased from four weeks to 10-12 weeks, the immunity response is better against the coronavirus infection. Both the approved vaccines in India are a two-shot protection regimen.
It might be tempting to undergo an antibody test days after getting a Covid-19 vaccine. But it is not a necessity. Experts say antibody production after a vaccine shot varies from person to person depending on a number of biological factors.
Some people may have an immediate response while others may show a delayed response to a vaccine shot. No antibody test is foolproof, experts also say. What is certain is that for most people getting a vaccine, their immune system is in a state of readiness to meet the challenge of a pathogen attack. The ultimate level of response may still vary.
Still, vaccines provide the best protection that is currently available against Covid-19. Vaccination may not prevent SARS-CoV-2 infection or its transmissibility from one person to another. But vaccines are preventing, as per trial records, the severity of Covid-19 illness.
So, should you go for antibody test? Well, that is essentially your own call.