It has been claimed by some news reports that a screening test conducted by King George Medical College (KGMU), Lucknow revealed that 7 percent of the tested healthcare workers did not produce antibodies in spite of being fully vaccinated.
To get to the bottom of this, FIT spoke to Dr Tulika Chandra, Head of Blood and Transfusion Department at KGMU.
Dr Chandra explains that such a study is indeed being conducted by the Blood and Transfusion Department. The study target has been set on 4000 healthcare workers of KGMU. However, at present, 1000 people have been tested.
She clarifies the results of the study.
She further explains that the lack of antibodies in 10% cannot be considered a sign of concern, because there are different reasons behind it. In fact, they are fairly encouraging.
The vaccine efficacy in India ranges from 70% to 80%. The results of the KGMU study are better as about 90% of the health workers have antibodies. The doctor says that if vaccination is done in the entire population, then the chain of corona infection can be broken.
Dr Chandra breaks down the data, explaining,
"These are initial observations. After completing the sample size, the detail analysis will be done," she adds.
What do antibody tests tell us about COVID vaccine efficacy?
First, a quick run down of how antibodies work and what COVID vaccines have to do with them.
Vaccines work by triggering the body's immune response into producing specific antibodies to fight of a specific pathogen, and observing the amount of antibodies produced by the person post vaccination can be a helpful indicator of the effectiveness of the vaccine.
In a previous story on FIT, we’d explained that there is a threshold of an antibody test.
The average count comes from 300 to 1000 after the second shot of the vaccine.
Speaking to FIT for another story, Dr Shahid Jameel explained that although it’s rare for antibodies to not be formed after vaccination, but it’s known to happen and can be attributed to some genetic abnormalities.
Dr VK Paul, chairman of the Central Government's COVID-19 Task Force and member of NITI Aayog, had also clarified this in a statement, saying,
According to Dr Jameel, the sensitivity and specificity (markers to indicate the accuracy of the test in detecting positive and negative cases) can also depend on a number of other factors such as the testing kit, the type of antibody test, and how many days after vaccination it is done.
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Published: 08 Jun 2021,05:58 PM IST