COVID-19 antibody tests provide important insights over time

Written by

Lauren Dobischok
25 December, 2021

Medically checked article All HOMED-IQ content is reviewed by medical specialists

The conversation on the usefulness and necessity of vaccination against COVID-19 – let alone the booster vaccination – is far from over. However, remarkably little attention is paid to the important role played by the (individually varying) antibodies against the coronavirus. In fact, there is hardly any widespread testing for COVID-19 antibodies. This is not only a pity for the individual, who misses important insight into his/her own health status, but as a society we also run the risk of not preparing adequately enough with the COVID-19 pandemic that is caused by the virus, especially as the new Omicron variant becomes more prevalent.

What are antibodies and why are they important?
COVID-19 antibodies are produced following either vaccination or exposure to the SARS-CoV-2 virus. Antibodies that can inactivate the virus, known as neutralizing antibodies, are an important indicator of an individual’s degree of protection against the virus (NVMM, 2021).
Antibodies don’t naturally exist in the body- they only arise after either an infection with the virus or through vaccination. In both cases, the immune system is ‘put to work’; In response to the invader (the virus or the vaccine), the immune system produces, among other things, T- and B-cells and antibodies that are supposed to neutralize this threat (Sanquin, 2021). In this process, IgA, IgM and IgG antibodies are produced. While IgA and IgM antibodies disappear from the body over time, IgG antibodies last longer and form an immune ‘memory’. This means that after a first exposure to COVID-19, the immune system will recognize the virus more quickly and is prepared to deal with it next time, thanks to the T, B and IgG memory cells. In subsequent exposures, individuals will often either not get sick or have milder symptoms (EOS, 2021).

How do antibodies protect us?

While antibodies can protect us from developing future infections, they are never 100% effective. This means that it is still possible to become infected with COVID-19 despite having antibodies and is called a breakthrough infection. However, people who have been vaccinated and thus have adequate antibodies have been found to have a lower risk of infection, severe illness, hospitalization, and death. While it is always possible that a breakthrough infection may occur, having antibodies are important in preventing serious illness, hospitalization, and death (CDC, 2021).

As with many diseases, antibodies to COVID-19 decrease over time. This means that after a certain period of time, your antibody level can fall below a level that provides adequate protection against the virus, also known as the “threshold of protection” (CDC, 2021). When your antibody level falls below this level, protection against the virus or severe illness decreases. The exact amount of time it takes for COVID-19 antibodies to fall below the threshold of protection is still unknown. Additionally, scientists are still studying how COVID-19 immunity works, and whether other parts of the immune system play a role in remembering the virus and offering protection. Despite these uncertainties, antibody testing allows individuals to check their antibody level and see whether their COVID-19 antibodies have fallen to low levels. This can help guide decisions on when to get booster doses of the vaccine, perhaps allowing those with very low levels of antibodies to access booster vaccines before those who still have high quantities.

Introduce an antibody test for everyone as soon as possible
Someone who sees the importance of knowledge about the level of COVID-19 antibodies in an individual is Outbreak Management Team (OMT) member and Intensive Care physician Dr. Diederik Gommers. In a broadcast of BNR Nieuwsradio on December 6, he argues in favor of introducing COVID-19 antibody tests as soon as possible. He states that this can help to relax the current COVID-19 measures. If sufficient antibodies are present, you have the reassurance that you can safely participate in society. If there are too few or no neutralizing antibodies, then that is the time to get a booster vaccination to improve protection. RIVM is currently investigating which tests would qualify for this and whether the introduction of antibody tests is feasible.

Antibody tests also prove their usefulness commercially
In addition to the role that antibody tests can play in society, they also provide valuable insights for employees in the business community and beyond. Due to both the Delta and the rapidly spreading Omicron variant, the use of an antibody test can give employees a little more certainty in the workplace, as antibody testing clarifies the importance of vaccination and possibly booster doses.

Simple and reliable
Homed-IQ’s laboratory-certified antibody tests provide reliable insight into the level of antibodies in the blood quickly and easily. Since the beginning of the pandemic, Homed-IQ has been a partner to public health institutions such as the NHS in large-scale antibody testing projects, allowing scientists to better understand COVID-19 immunity with time.

Would you like to learn more? Listen here to the podcast in which Gommers argues for the introduction of antibody tests (In Dutch).

Nederlandse Vereniging voor Medische Microbiologie (NVMM). Serologie. Beschikbaar via Laatst geraadpleegd op 15 december 2021.
Sanquin. Antistoffen tegen het coronavirus: heel veel vragen en nog weinig antwoorden. Beschikbaar via Laatst geraadpleegd op 15 december 2021.
EOS. Coronavirus: wat je moet weten over B- en T-cellen. Beschikbaar via Laatst geraadpleegd op 15 december 2021.
Centers for Disease Control and Prevention. Antibodies and COVID-19. Beschikbaar via
Laatst geraadpleegd op 29 december 2021.

About the author

Lauren Dobischok

Lauren is a health scientist and science communicator currently living in the Netherlands. Originally from Canada, she completed a Research Master’s in Health Sciences at the Netherlands Institute of Health Sciences at Erasmus University Rotterdam (NIHES) with a specialisation in epidemiology. Prior to her master’s degree, she completed a Bachelor’s degree in Health Sciences at Simon Fraser University. With a background in public health, her goal is to create accurate scientific content that is easy to understand and empowers people to make informed decisions. Within Homed-IQ, Lauren works as a Product Developer and Content Lead, working closely with physicians and scientists on medical devices for Homed-IQ’s new products and written communications.