Following the announcement from Khairy urging the people to avoid going for the Covid-19 antibody test yesterday (7 August), a health expert had confirmed Khairy’s advice and said that there are currently no antibody tests that will give an accurate or complete picture of one’s immune response against Covid-19.
Universiti Malaya epidemiologist Prof Datuk Dr Awang Bulgiba Awang Mahmud said that the usefulness of antibody test, or serology test, after the Covid-19 vaccination, remained uncertain for now.
He added that different vaccines will cause our body to produce different antibodies and a test not designed for that specific antibody may not be able to detect it.
For example, a mRNA vaccine such as Pfizer will induce the production of antibodies to the spike protein of the virus, but not antibodies to the nucleocapsid protein.
“As such, a person vaccinated with an mRNA vaccine will not test positive in an antibody test if the test is for antibodies to the nucleocapsid protein.”
“Moreover, the level of antibodies depends on the person’s immune system response and how long ago the vaccination was carried out. It is expected that antibody levels will wane over time and it would be wrong to make comparisons directly.” he said in an interview with The Star.
This comes after some individuals whom had concerns of whether they had truly received the jab, following the multiple reports of empty syringes or vaccine leak incidents. Some claimed that they were tested negative for antibodies even after receiving the Covid-19 vaccine.
Responding to the matter, Dr Awang Bulgiba said that the body’s immune system is far more complex and it does not depend solely on a high level of circulating antibodies.
“There are the B-cell and T-cell responses which are also important. If vaccination results in adequate numbers of memory cells and T-cells, reinfection will elicit the appropriate response and the person should be able to fight off the infection.” he said.
The mentioned B-cells and T-cells are major components of the body’s adaptive immune response, with the B-cells producing antibodies to destroy invading viruses and bacteria, and T-cells directly fighting against such pathogens.
Nonetheless, Dr Awang Bulgiba said that there were many local health screening companies out there offering such antibody tests which would typically cost more than RM100 presently.
“A clear advisory needs to be issued by the health authorities on the appropriateness of these tests and how the test can be interpreted.”
“Otherwise, there may be claims of ineffectiveness of the vaccines as a result of antibody testing, which can be detrimental to the vaccination programme.” he said.
Meanwhile, he praised the government’s decision to monitor on the neutralising antibodies, B-cells and T-cells among vaccine recipients.
“This follow-up will aid decision-making on whether third doses will be required, and for which vaccines, and whether antibody testing is required for the future.” he said.
On the other hand, Prof Dr Moy Foong Ming, who is from Universiti Malaya’s Social and Preventive Medicine Department, also agreed that the current antibody tests should not be used to evaluate a person’s level of protection after vaccination.
She added that unless there are new tests capable of detecting antibodies to specific protein targets, those currently available were unlikely to give an accurate picture of a person’s immune response post-vaccination.
“Until a new Covid-19 antibody test is developed to test the specific viral protein targets by the specific vaccine, the public should not waste time and money on antibody tests.” she said.
Another expert, Malaysian Society of Allergy and Immunology president Prof Dr Baharudin Abdullah, had previously said it was unclear whether such a test had any value in determining a person’s immune response post-vaccination.
On the international stage, the Food and Drug Administration of the United States currently does not recommend antibody testing as a means to assess immunity levels after someone has received a Covid-19 vaccination.
“While a positive antibody test result can be used to help identify people who may have had a prior SARS-CoV-2 infection, more research is needed in people who have received a Covid-19 vaccination.”
“Test results from currently authorised SARS-CoV-2 antibody tests should not be used to evaluate a person’s level of immunity or protection from Covid-19.” they said.
, a health expert had confirmed Khairy's advice and said that there are currently no antibody tests that will give an accurate or complete picture of one's immune response against Covid-19.){kind=link}