How Do You Know Your Vaccine Is Working?

A titer value test helps estimate the number of antibodies in the body specific to a type of pathogen. Thus, it indirectly gives an idea of the vaccination’s impact and efficacy. 

How would you respond if I asked whether the vaccine shots you have taken throughout your life are effectively working or not? We take jabs as and when required and then move on with our lives. However, if there aren’t any side effects, and no mention of the disease is ever made, then how do you know the vaccine isn’t just water? And what if you can’t remember whether you’ve been vaccinated against a disease in the first place?

Thanks to modern medical technology, we can answer those questions! We just have to take a “titer value test” to discover all the answers. 

You have misplaced your vaccination record and now you might have to get ALL those vaccine shots again

First, we will have a brief review of how the body’s immunization system works!

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The Antigen-antibody Reaction

An antigen is a foreign substance that, upon entering the body, elicits an immune response. It is an unwanted visitor to the body, so the body does everything it can to get rid of it as soon as possible. Bacteria, viruses and toxins are just a few examples of antigens.

Once the antigen enters the body, specific cells called lymphocytes (a type of white blood cell responsible for the immunity of the body) get activated and take up arms against the antigen. The lymphocytes soon start producing and secreting protein molecules called antibodies. 

Antibodies then go and bind to the antigens, which helps protect the body against the antigen’s effects. Antibodies are very specific to the antigens for which they have been released. 

This is the principle behind immunization. A small amount of antigen, in the form of a dead or weakened pathogen, is injected into the body. This elicits an immune response from the body, which starts producing antibodies against it, usually within 14 days. 

Along with the production of antibodies, cells called memory T cells (a type of lymphocyte) retain the ‘memory’ of the antigen. What this does is that if the same or a similar pathogen enters the body, the body’s response against it is quicker and more effective. Meanwhile, the preformed antibodies (from the vaccination) fight the pathogen. 

Titer Value Test

A titer value test is a simple laboratory test that can determine whether one has been vaccinated against a pathogen. Additionally, such a test can answer whether the vaccine that was administered is effectively working or not. But how does it do that?

Quite simply, the test estimates the number of antibodies present in the blood.

A small amount of blood is taken using a syringe. The sample is then sent to the lab to assess the presence of specific antibodies against a pathogen. The amount of antibodies in the sample of blood is then corresponded to the total amount of blood in our body. 

There is a set and standard value for the amount of each type of antibody. If the antibody concentration in our blood sample comes out to be above that value, then hurray, we’re good to go! 

Also Read: If A Vaccinated Person Donates Their Blood, Does Its Receiver Gets Their Immunity?

If the report is positive, you are considered vaccinated and your vaccination is effectively working. If the report is negative, you might want to get yourself vaccinated as soon as possible. The report can, however, also be “equivocal”, which means not having enough immunity. In that case also, one must also get a new vaccine jab as soon as possible. 

What Does This Test Determine?

Apart from giving us an idea of our previous vaccinations and checking the efficacy of the vaccine, an antibody titer test can also be used to determine the body’s immune response to its tissues. In this was, doctors can determine whether the body is producing antibodies and what amount of antibodies have already been produced against its own cells.

This situation is called an autoimmune disease, which can prove fatal, since the body’s immune system starts recognizing its own body’s tissues as foreign and seeks to destroy them.  


A titer test begins by collecting a blood sample. (Photo Credit : Saiful52/Shutterstock)

Not only this, but the test also helps in determining whether one has had recent or past infections. A high number of antibodies indicates a recent infection, whereas a slightly lower number indicates an infection in the past.

And if you’re wondering whether all of this requires a doctor, you don’t need a doctor’s prescription. You can get an antibody test done without your doctor even knowing! Your doctor, however, might prescribe an antibody titer test to confirm your previous vaccination in case you have lost the records and your memory isn’t 100% clear. 

The doctor might also use it to rule out any infection or check for the presence of an autoimmune disease. Antibody titer tests are sometimes required if you work in the healthcare sector. Your employer might want to confirm your previous vaccinations and their efficacy. 

The Results

If the test is done to check antibodies against the body’s tissues, the normal value must come out to be zero or negative. 

However, if the test is done to determine the presence of antibodies against a pathogen, the value should come out to be higher than a certain specified value. That certain specified value represents the minimum amount of antibodies that must be present in the blood for the body to provide effective immunity. 

This certain specified value varies with different antibodies against their respective antigens. Also, if the titer test results are lower than the specified value, it implies that the body does not have sufficient antibodies to deal with the pathogen upon its arrival. A vaccine must be administered in such cases. 

If the test result is negative or zero, it implies the body does not have antibodies against that particular pathogen. Apart from implying the absence of vaccine administration, it also helps in eliminating doubt for particular infections.


Do you need to get vaccinated again? (Photo Credits:WeStudio Photographers/Shutterstock)

Let’s say the doctor wants to check whether a patient has tuberculosis. Now, if the titer value test comes out to be zero, it implies that no vaccine has been taken against tuberculosis. However, it also means that the person is not infected by the tuberculosis pathogen. Had the patient been infected, some amount of natural antibodies would be present in their blood.

Also Read: Vaccine Ingredients: What Are Vaccines Made Of?

A Final Word

Nevertheless, thanks to science and its simple yet logical ways, we have a solution to almost everything. Lost your vaccination records? No worries. Want to know the working efficiency of your vaccine? Not a problem. Want to diagnose an autoimmune disease? We’ve got you covered.

Now, have you ever wondered whether donating your blood will provide the receiver with your immunities? Find the answer here! 

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About the Author

Pragyanshi is pursuing MBBS from BRD Medical College, India. She developed an interest in science right when she was introduced to it and since then has been eagerly trying to find scientific answers to all the conceptions-misconceptions-superstitions which tend to float around. She’s a bibliophile and wouldn’t complain if you send her to a dungeon with books.