How do antibodies work against diseases?

This article was published on
May 31, 2021

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Most COVID-19 vaccines, just like natural infections, produce substantial antibodies in people who have received them. Antibodies help the immune system fight infections by latching onto antigens and marking them for destruction.

Most COVID-19 vaccines, just like natural infections, produce substantial antibodies in people who have received them. Antibodies help the immune system fight infections by latching onto antigens and marking them for destruction.


What our experts say

The body's immune system is like its military. It provides a natural defense against any foreign invaders and threats, which we call 'pathogens'. Pathogens can be things like viruses, bacteria, and microorganisms that are trying to use the body as a host to divide and multiply.

When the immune system recognizes a pathogen, one of its most important responses is releasing something called antibodies. Antibodies find key parts of a virus and mark it so our bodies know to kill it.

After we get infected with something, our immune systems often remember how to make the antibodies that can launch a defense against the pathogen. Antibodies aren't the only function involved our immune response to a pathogen, but they are one of the strongest estimators of how much protection someone has against an invader.

The number of COVID-19 antibodies someone has may indicate how protected that person is from the virus. A recent preprint study, which has not been reviewed or formally criticized by other scientists in a scientific journal, noted that COVID-19 vaccines may produce ten times more antibodies than getting and recovering from COVID-19.

COVID-19 vaccines have been shown to produce substantial numbers of antibodies in people who received them. Contrary to some online claims, the vaccines do not destroy antibodies for other diseases or viruses.

Context and background

Social media has seen an increase in theories about antibody production and destruction as a result of COVID-19 infections. Antibodies can be a strong predictor of a person's immunity against a virus. Vaccines and natural infections both produce antibodies, though we still need more research to determine the difference between vaccine and natural antibody production levels.

Natural immunity and vaccine protection are not always equal in each person. This is why health professionals and scientists are strongly urging people who've survived COVID-19 infections to get vaccinated. We know more about the high level of protection the vaccines offer us than we do about how natural infections impact huge populations. It is highly likely that vaccines offer more significant, predictable protection than natural infections can.

We do not know what immunity looks like for people, or how many antibodies each person creates, after infection. We do know some people have no antibodies at all after recovering from COVID-19, while others have a minimal response. We do not know how long that immunity lasts in each person, how strong that protection is, and if it will be susceptible to different variants.

We do know that the current COVID-19 vaccines have been effective at producing an antibody response, and both natural immunity and vaccines generate T-cell responses, another critical aspect of immune system protection. We also know that current COVID-19 vaccines are safe, more reliable than natural immunity, are significantly less dangerous than COVID-19 infections, and likely produce many more antibodies than natural infections can.

Current data shows us that roughly 10% of infected people do not have measurable antibodies once they recover from COVID-19, 7% don't have T-cells that remember the virus one month after infection, and up to 5% of people may lose their natural immunity within a few months. Compare that to vaccines, where a recent study showed that four months after receiving one dose of the Moderna vaccine, 100% of all participants produced antibodies. These antibody levels were much higher in vaccinated people than in those who had natural immunity to the virus. The difference can be six to ten times higher in those who have received the injections.

Antibody production varies in people who have had mild or asymptomatic infections, especially when compared to those who have been hospitalized or had severe symptoms. With the vaccine, almost all recipients tested have seen a robust immune system response, including increased antibody levels.

However, some recent studies have noted that people who have had infections may not benefit as much as those who had not been infected, if at all. Despite this lack of potential benefit that may exist, doctors still overwhelmingly urge people who have been infected to receive the vaccine for both their own health and the health of their communities. More research is needed and will continue occurring in this space for the foreseeable future.


  1. SARS-CoV-2 escaped natural immunity, raising questions about vaccines and therapies (Nature Medicine)
  2. mRNA vaccine-elicited antibodies to SARS-CoV-2 and circulating variants (Nature)
  3. Substantial Differences in SARS-CoV-2 Antibody Responses Elicited by Natural Infection and mRNA Vaccination (bioRxiv)
  4. How do vaccines work? (World Health Organization)
  5. How does the immune system work? (Institute for Quality and Efficiency in Health Care)
  6. 10 Things to Know About Antibodies (Amgen Science)
  7. What are antibodies? (Live Science)
  8. Antibodies (New Scientist)
  9. Durability of Responses after SARS-CoV-2 mRNA-1273 Vaccination (The New England Journal of Medicine)
  10. Safety and Immunogenicity of SARS-CoV-2 mRNA-1273 Vaccine in Older Adults (The New England Journal of Medicine)
  11. Do I need a vaccine if I’ve already had COVID-19? (UChicago Medicine)
  12. Antibody Responses in Seropositive Persons after a Single Dose of SARS-CoV-2 mRNA Vaccine (The New England Journal of Medicine)
  13. Necessity of COVID-19 vaccination in previously infected individuals (medRxiv)
  14. Natural vs Vaccine Immunity for COVID: Is One More Effective? (MedPage Today)
  15. Why you should get a COVID-19 vaccine – even if you’ve already had the coronavirus (The Conversation)

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