This can happen if you get an antibody test too soon after being exposed or vaccinated and your body has not yet made enough antibodies to be detected by the test. Response and Duration of Serum Anti-SARS-CoV-2 Antibodies After Inactivated Vaccination Within 160 Days. If you have a negative antibody result, you would need to speak to your doctor to determine next steps on an individual basis. Panel B: Specific antibody titers in subjects with previous exposure to SARSCoV2 after a single or two doses of vaccine. Different COVID vaccines work in different ways, but they all aim to train your immune system to recognise and remember coronavirus. You should wait at least two weeks after a one-dose vaccine or two weeks after the final shot of a two-dose vaccine to get an antibody test so your body has the chance to produce detectable antibodies. The FDA is providing additional information and recommendations to the public and health care providers about the use of antibody tests in people who received a COVID-19 vaccination. A Multi-Centre, Randomised, Double-Blind, Placebo-Controlled Phase III Clinical Trial Evaluating the Impact of BCG Re-Vaccination on the Incidence and Severity of SARS-CoV-2 Infections among Symptomatic Healthcare Professionals during the COVID-19 Pandemic in Poland-Evaluation of Antibody Concentrations. Two main types of cell are important in your immune response to vaccination: B cells and T cells. Oxford Immunotec is collaborating with researchers at the University of Leicester on DIRECT (Determining the . Please note, it may take 14-21 days to produce detectable levels of IgG following infection. 10.1016/S1473-3099(20)30843-4 Consult with your physician about your results. Neutralizing antibodies are typically IgG antibody tests but can also be IgA (immunoglobulin A) antibody tests. Change the lives of cancer patients by giving your time and talent. 2021;21(2):181192. Your results will be reported to public health authorities where required by law. Unable to load your collection due to an error, Unable to load your delegates due to an error. A vaccinated person should not be alarmed or worried if they receive a negative antibody test result because this test does not detect antibodies from the Pfizer, Moderna and Johnson & Johnsons Janssen COVID-19 vaccines, which were developed against the spike protein of the virus, says Fernando Martinez, M.D., medical director of Laboratory Medicine. 2022 Sep;32(9):2987-2993. doi: 10.1007/s11695-022-06181-y. Log in to our secure, personalized website to manage your care (formerly myMDAnderson). COVID-19; SARS-CoV-2; humoral immunity; spike RBD; spike m-RNA vaccine. FOIA It should show TWO results: (1) the spike antibodies to the virus (which should be negative if you've never had Covid) and (2) the antibodies to the vaccine (which should be positive if you've . Antibodies could be present at levels below the tests threshold for detection. If you request a test through our online process, Labcorp will bill the cost test directly to your health plan if you are insured. 2020. There are many questions that come up if youre thinking about getting an antibody test after the COVID-19 vaccine: What will the results tell me? IgG (immunoglobulin G) antibodies are found in all body fluids and are the most common, making up 75 to 80 percent of the antibodies in your body, per Michigan Medicine. The same thing happens when you get a vaccine, like a . However, it doesnt prove that there has been no prior or current infection. Labcorp is providing serology testing based on tests from various manufacturers. The risk [for immunocompromised patients] is that you may be operating under the false belief that youre protected, and you might not be, says rheumatologist Jeffrey Curtis, MD, MPH, a Professor of Medicine at the University of Alabama at Birmingham who led the task force that created the ACR COVID-19 Vaccine Clinical Guidance. doi: 10.1128/Spectrum.00965-21. You have a condition that weakens your immune system. All Rights Reserved.Lymphoma Action is a registered charity in England and Wales (1068395) and in Scotland (SC045850). Patient Sentiment toward Non-Medical Drug Switching, preventive steps to take after getting the vaccine if youre immunocompromised, https://www.fda.gov/news-events/press-announcements/coronavirus-covid-19-update-fda-authorizes-first-test-detects-neutralizing-antibodies-recent-or, https://www.uofmhealth.org/health-library/hw41342, https://www.cdc.gov/coronavirus/2019-ncov/lab/resources/antibody-tests-guidelines.html, https://www.hopkinsmedicine.org/health/conditions-and-diseases/the-immune-system, The Risk Factors for Long COVID Are Still Ambiguous But Heres What You Should Know if Youre Immunocompromised, 5 Reasons Why Your Doctor May Not Prescribe Paxlovid If Youre High-Risk and When to Get a Second Opinion, Yet Another Symptom: Dealing with Long-Haul Covid as a Person with Chronic Illness, Catinas Journey with Chronic Illness: From Hiding to Helping, Study Suggests Strong Link Between Inflammatory Bowel Disease and Rheumatic Disease. Join now. The site is secure. Here, we list a few things to consider before deciding whether or not to pay for a test. Nature. 2023 Jan 4;24(2):908. doi: 10.3390/ijms24020908. Here, we list a few things to consider before deciding whether or not to pay for a private test. 99.6% of the volunteers developed seropositivity 4 weeks after the second dose of vaccine. On May 19, 2021, the FDA issued a safety communication reiterating that antibody testing should not be used to evaluate a persons level of immunity or protection from COVID-19 at any time, and especially after the person received a COVID-19 vaccination. (Many insurance plans or employee wellness plans offer convenient telemedicine programs.). The receptorbinding domain of the viral spike protein is an immunodominant and highly specific target of antibodies in SARSCoV2 patients. Talk to your healthcare provider for more information. Immunogenicity and Safety of the BNT162b2 COVID-19 Vaccine in Patients with Cystic Fibrosis with or without Lung Transplantation. Antibody response to SARS-CoV-2 vaccination, previous SARS-CoV-2 infection, and change to single-dose vaccination. So if you did score high. The authors declare that there are no conflict of interests. This is is why you develop antibodies after natural infection with a virus and after getting a vaccine. National Library of Medicine Because of that, it can be challenging to compare neutralizing antibody tests between studies and labs. Nobody knows that for healthy people, and nobody knows that for immunocompromised people, adds Dr. Curtis. In this study, we determined antibody levels at baseline and 3 weeks after the first dose of the BNT162b2 SARS-CoV-2 mRNA vaccine in 36 health care workers who received laboratory confirmation of . We studied spike-specific antibody responses following first and/or second Covid-19 vaccination in 299 patients with CLL compared with healthy donors. If youd like to talk, contact our Helpline Services on freephone 0808 808 5555 from 10am to 3pm, Monday to Friday, or via Live Chat through our website. Nat Microbiol. 8600 Rockville Pike We used non parametric tests and Pearson correlation test to perform inferential analysis. These neutralizing antibodies are typically of more interest when studying vaccine-induced immune responses and determining vaccine-induced protection, says Dr. Ramirez. Values are differentiated between subjects with previous asymptomatic infection and subjects with previous COVID19. 2021 Dec;93(12):6456-6457. doi: 10.1002/jmv.27221. IgA antibodies are found in body parts like your nose, breathing passages, and digestive tract, per Michigan Medicine. IgM is more often seen early in infection or early after vaccination.. In the case of someone making antibody levels that are too low to detect, it is possible that the antibody levels would rise to a detectable level over time say, if the test was performed too soon or that the antibody levels would rise to a detectable level following a booster dose of the vaccine, says Dr. Ramirez. PWNHealth is an independent healthcare provider network that provides oversight services to you in connection with the testing you have requested. In the months after an infection, antibody levels may decrease below the detectable level. The .gov means its official. Evaluation of antibody response after COVID-19 vaccination of healthcare workers The common goal of all vaccines developed against COVID-19, although they have been designed with different methods, is to develop an effective immunity and antibody response against SARS-CoV-2. Its thought that vaccination also causes a T cell response in your body. Antibody testing isnt conclusive for predicting COVID-19 immunity. Please note: if your insurance doesn't cover the cost of the test, you may receive an invoice from Labcorp for up to $42.13. T cells also help improve the antibody responses that are made to the SARS-CoV-2 virus.. In the human adaptive immune system, we have two different types of responses to infections: B cell responses (responsible for producing antibodies), and T cell responses. Careers. PWNHealth and its services are independent from Labcorp. -. J Med Virol. Adverse events after vaccine injection were more frequent after the second dose of vaccine (mean: 0.95; 95% confidence interval [CI]: 0.75-1.14 vs. mean: 1.91; 95% CI: 1.63-2.19) (p < .0001) and in exposed compared to nave (mean: 1.63; 95% CI: 1.28-1.98 vs. mean: 2.35; 95% CI: 1.87-2.82) (p = .015). COVID19, coronavirus disease 2019. Researchers can then determine how well the antibodies block the virus from infecting the cells. About 10 to 15 percent of your antibodies are IgA antibodies, but some people dont make them. -. Effective March 28, 2022, Labcorp expanded the reporting range of results for test number 164090 SARS-CoV-2 Semi-Quantitative Total Antibody, Spike. Epub 2021 Nov 10. Your Spike Protein Antibody results will be reported as a reference range: >/= 0.80 U/mL: This is a positive result for anti-SARS CoV-2S. In vaccinated people: The site is secure. It takes one to three weeks after an infection for antibodies to be detectable. | Charity web design by Fat Beehive, Post-transplant lymphoproliferative disorder, Lymphoma TrialsLink (clinical trials database), Sign up for education and training updates, Fundraise with family, friends and colleagues. Epub 2022 Feb 19. Theres also a difference between having no antibodies and having some antibodies. Vaccines (Basel). Xu QY, Xue JH, Xiao Y, Jia ZJ, Wu MJ, Liu YY, Li WL, Liang XM, Yang TC. If you think you had a problem with a SARS-CoV-2 antibody test, the FDA encourages you to report the problem through the MedWatch Voluntary Reporting Form. Bethesda, MD 20894, Web Policies These are sometimes called an anti-S test because they test for antibodies that react to the spike protein. These types of tests cannot be used to diagnose a current infection. PWNHealth is a network of physicians who reviews your test request and submits a physician's order for the test. Health care workers (184) with a previous SARS-CoV-2 infection were sampled soon before the second dose of vaccine and between 7 and 10 days after the second dose, the last sampling time was applied to SARS-CoV-2 nave individuals, too. Antibodies that work against SARS-CoV-2 - the virus that causes COVID-19 - are usually detectable in the first few weeks after infection. 10.1056/NEJMoa2034577 A positive test result with the SARS -CoV-2 antibody test indicates that antibodies to SARS -CoV-2 were detected, and the individual has potential ly been exposed to Michigan Medicine. Some T cells respond by making substances that aim to kill the virus. CreakyJoints is a digital community for millions of arthritis patients and caregivers worldwide who seek education, support, advocacy, and patient-centered research. They involve pricking your finger with a small needle and collecting a few drops of blood in a tube. The Centers for Disease Control and Prevention (CDC) discourages antibody testing for assessing immunity after getting the vaccine. PMC Careers. Nitahara Y, Nakagama Y, Kaku N, Candray K, Michimuko Y, Tshibangu-Kabamba E, Kaneko A, Yamamoto H, Mizobata Y, Kakeya H, Yasugi M, Kido Y. Microbiol Spectr. This spike. Theyre very important in fighting viral infections. 2021 Dec;93(12):6474. doi: 10.1002/jmv.27263. Front Immunol. If youve been exposed to COVID-19 or vaccinated, your body produces antibodies as part of your immune response. Learn more about our FREE COVID-19 Patient Support Programfor chronic illness patients and their loved ones. After a single vaccine injection, the median titer of specific antibodies in individuals with previous coronavirus disease 2019 was 30.527 U/ml (interquartile range [IQR]: 19.992-39.288) and in subjects with previous SARS-CoV-2 asymptomatic infection was 19.367.5 U/ml (IQR: 14.688-31.353) (p = .032). You can view and print your results bysigning in or creatinga Labcorp Patient account. SARS-CoV-2-The Role of Natural Immunity: A Narrative Review. Zapolnik P, Kmiecik W, Nowakowska A, Krzych J, Szymaski H, Stopyra L, Jackowska T, Darmochwa-Kolarz D, Mazur A, Czajka H. Vaccines (Basel). Interim Guidelines for COVID-19 Antibody Testing. Antibody Test. In this study we verified if, in individuals with a previous SARS-CoV-2 infection, a single dose of messenger RNA (mRNA) vaccine would be immunologically equivalent to a full vaccine schedule in nave individuals. There isnt enough data on immunocompromised populations yet to determine how they may react to the vaccine, but experts still believe youll get some immunity which is far better than none if you are immunocompromised. 286 patients underwent extended interval (10 . Lozano-Ojalvo D, Camara C, Lopez-Granados E, Nozal P, Del Pino-Molina L, Bravo-Gallego LY, Paz-Artal E, Pion M, Correa-Rocha R, Ortiz A, Lopez-Hoyos M, Iribarren ME, Portoles J, Rojo-Portoles MP, Ojeda G, Cervera I, Gonzalez-Perez M, Bodega-Mayor I, Montes-Casado M, Portoles P, Perez-Olmeda M, Oteo J, Sanchez-Tarjuelo R, Pothula V, Schwarz M, Brahmachary M, Tan AT, Le Bert N, Berin C, Bertoletti A, Guccione E, Ochando J. Callie Botsford, who caught Covid-19 in March 2020 and was vaccinated against the virus in March this year, had a result of over 40,000 for her recent antibody test. 2020;5(10):11851191. 2022 May;118:116-118. doi: 10.1016/j.ijid.2022.02.036. It can take up to two weeks for your body to develop antibodies after infection or a vaccination shot, so you should wait to get an antibody test until 10 days after your symptoms started or 10 days after testing positive. Please enable it to take advantage of the complete set of features! They do not measure your memory B cells or test whether your T cells have responded. This means you have not been infected with COVID-19. Some T cells respond by activating B cells and telling them to make lots of antibodies. These tests have not been FDA cleared or approved but they have been authorized by the FDA under an emergency use authorization for use by authorized laboratories. La informacin contenida en el sitio web de CreakyJoints Espaol se proporciona nicamente con fines de informacin general. Having a negative antibody result doesnt necessarily mean you havent responded to vaccination you might have a T cell response that may provide some protection. The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). These antibodies stick around to defend against the invader in case it ever comes back. The mRNA vaccine induces a strong antibody response to SARS-CoV-2 and five VOCs at 1 week post-vaccination that decreases thereafter. Antibody response after a third dose mRNA-1273 vaccine among vaccinated healthcare workers with two doses of inactivated SARS-CoV-2 vaccine. An official website of the United States government, Recalls, Market Withdrawals and Safety Alerts, Antibody Testing Is Not Currently Recommended to Assess Immunity After COVID-19 Vaccination: FDA Safety Communication, Antibody (Serology) Testing for COVID-19: Information for Patients and Consumers, recommendations for fully vaccinated people, Serology/Antibody Tests: FAQs on Testing for SARS-CoV-2, Centers for Disease Control and Preventions guidelines, report the problem through the MedWatch Voluntary Reporting Form. Antibodies are proteins your immune system makes to fight infection. Anti-SARS-CoV-2 IgG Antibodies Post-COVID-19 or Post-Vaccination in Libyan Population: Comparison of Four Vaccines. Most clinical tests do not look for IgA, but IgA can be neutralizing, says Dr. Ramirez. official website and that any information you provide is encrypted Taking fewer steps to protect against SARS-CoV-2 can increase their risk of SARS-CoV-2 infection and may result in the increased spread of SARS-CoV-2. Antibody tests may help identify past SARS-CoV-2 infection if performed two to four weeks after symptom onset. We evaluated neutralizing antibody (NAbs) levels as a protective factor against vaccine breakthrough infection (VBI) in healthcare workers (HCWs) during the third COVID-19 wave in Peru. Bethesda, MD 20894, Web Policies It is possible to receive vaccines and not develop antibodies, says Dr. Ramirez. Antibody tests are not used if you have symptoms of COVID-19 or for diagnosing a current case of COVID-19. < 0.80 U/mL: This is a negative result for anti SARS CoV-2S. and transmitted securely. Negative: You tested negative for COVID-19 IgG antibody. Are there limitations to the COVID-19 antibody tests? Theres not just one arm of the immune system, says Dr. Adalja. They are also quantitative in that they show how many neutralizing antibodies are present. Lancet Infect Dis. Your immune systems T cells might not be able to prevent SARS-CoV-2 infection unless there is a low level of virus, but they are likely important for clearing the SARS-CoV-2 virus from the body once infection has occurred. , an infectious disease doctor and researcher at the University of California San Diego and. Results previously reported for this assay were 0.8-2500 U/mL with higher values reported as >2500 U/mL. The https:// ensures that you are connecting to the For more information about antibody testing, see Antibody (Serology) Testing for COVID-19: Information for Patients and Consumers. sharing sensitive information, make sure youre on a federal OXFORD, United Kingdom and MARLBOROUGH, Mass., April 29, 2021 (GLOBE NEWSWIRE) -- Oxford Immunotec a global, high-growth diagnostics company part of PerkinElmer (NYSE: PKI), today announced that its T-SPOT Discovery SARS-CoV-2 kit will be used for T cell testing in the DIRECT study. Can I use a semi-quantitative COVID-19 antibody test to track my antibody levels over time? Yang S, Li Y, Dai L, Wang J, He P, Li C, Fang X, Wang C, Zhao X, Huang E, Wu C, Zhong Z, Wang F, Duan X, Tian S, Wu L, Liu Y, Luo Y, Chen Z, Li F, Li J, Yu X, Ren H, Liu L, Meng S, Yan J, Hu Z, Gao L, Gao GF. CreakyJoints.org n'est pas destin se substituer un avis mdical professionnel, un diagnostic ou un traitement. Your body makes these when it fights an infection, like COVID-19. One hundred and eighty-one of the participants were female (57.6%) with a median age of 39 (interquartile range [IQR], 10) and 133 (42.4%) were male with a median age of 41 (IQR, 11). 2022 May;52(3):511-525. Currently authorized SARS-CoV-2 antibody tests, including the SARS-CoV-2 Semi-Quantitative Total Antibody assay (164090), have not been evaluated to assess the level of protection provided by an immune response to COVID-19 vaccination. A positive result suggests that you had COVID-19 at some time in the recent past, even if you didnt show any symptoms. The .gov means its official.Federal government websites often end in .gov or .mil. Liang B, Xiang T, Wang H, Li Z, Quan X, Feng X, Li S, Lu S, Fan L, Xu L, Wang T, Wang X, Zhu B, Wang J, Yang D, Liu J, Zheng X. PMC This test checks for antibodies to COVID-19 after exposure or vaccination and provides a numerical value that indicates the level of antibodies present. Safety, tolerability, and immunogenicity of an inactivated SARSCoV2 vaccine in healthy adults aged 1859 years: a randomised, doubleblind, placebocontrolled, phase 1/2 clinical trial. Join the Global Healthy Living Foundations free COVID-19 Support Program for chronic illness patients and their families. . ThisCOVID-19 semi-quantitative test is for individuals who think they may have antibodies from infection or vaccination but who do not currently have symptoms of COVID-19. The best thing you can do right now: Get the COVID-19 vaccine and continue to follow standard mitigation measures to avoid exposure to the virus. If you have questions, email the Division of Industry and Consumer Education (DICE) at DICE@FDA.HHS.GOV or call 800-638-2041 or 301-796-7100. Information for test developers can be found at: FAQs on Testing for SARS-CoV-2. Biosensors (Basel). Differential effects of the second SARS-CoV-2 mRNA vaccine dose on Tcell immunity in naive and COVID-19 recovered individuals. -, Smits VAJ, HernndezCarralero E, PazCabrera MC, et al. The FDA provided updated information about SARS-CoV-2 antibody tests and will continue to keep health care providers and the public informed if new additional information becomes available. 2022 Nov 24;10(12):2002. doi: 10.3390/vaccines10122002. government site. Request an appointment at MD Anderson online or by calling 1-877-632-6789. SARS-CoV-2 mRNA Vaccines Elicit Different Responses in Immunologically Nave and Pre-Immune Humans. MeSH Follow up with your healthcare provider for additional guidance on how to interpret your test results. U.S. Centers for Disease Control and Prevention. Learn if you've been exposed to the virus or if you've built up antibodies from a vaccine or previous infection. There are currently too many unknowns to get an antibody test after a COVID-19 vaccine and expect any tangible takeaways, even or especially if youre immunocompromised. The way that neutralization is measured also varies, and some tests are much more sensitive than others. It is a personal decision whether or not you choose to pay for private antibody testing. Taking fewer precautions against SARS-CoV-2 exposure can increase their risk of infection and may result in increased spread of SARS-CoV-2. HHS Vulnerability Disclosure, Help In most places, antibody tests to check your response to COVID vaccination are not routinely available on the NHS. 2020;5(48.eabc8413). However, there is still a lot that experts dont know about how the vaccine works in immunocompromised patients, how to interpret the results of antibody tests after you get vaccinated against COVID-19, and what steps could be taken if you didnt confer enough protection. All Rights Reserved. Heres why you shouldnt be surprised to get a negative result even if youve received a COVID-19 vaccine. Tests of T cell response are not routinely available, either on the NHS or privately, although they are used in some clinical trials. your type of lymphoma and any other illnesses you have, whether you are on, or have recently finished, treatment, the level of COVID-19 infection in your area, how much contact you have with other people at home, socially and at work, your personal risk of becoming severely ill if you do get COVID-19. However, the postvaccination immune response and antibody levels differ between individuals. You want to make sure youre getting tested for antibodies to the spike protein, because thats what you would expect to get after the vaccine, says Dr. Adalja. 10.1016/S1473-3099(20)30987-7 Heres more information on preventive steps to take after getting the vaccine if youre immunocompromised. You have received aCOVID-19 vaccineand want to know if you have detectable antibodies. Vaccines teach your body to mimic this response without you actually getting sick. On the other hand, you may be worried if your antibody test doesnt show a high level of antibodies but it may not be revealing the full picture. SARS-CoV-2 mRNA vaccine induces robust specific and cross-reactive IgG and unequal neutralizing antibodies in naive and previously infected people. How effective is COVID-19 vaccination for people affected by lymphoma? Our personalized portal helps you refer your patients and communicate with their MD Anderson care team. There is also not much guidance on how to prioritize additional doses of vaccine for this kind of scenario, while the United States and much of the world is still in the process of administering first and second doses of vaccine to individuals who have not yet been fully immunized.. The test is not able to differentiate whether the antibodies produced were in response to the vaccine or to a prior infection. So it's important that you're not tested too soon. The common goal of all vaccines developed against COVID-19, although they have been designed with different methods, is to develop an effective immunity and antibody response against SARS-CoV-2. A positive result means your body's immune system has generated a response to the COVID-19 vaccine. You have been diagnosed with COVID-19 less than 10days ago. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely. A negative result suggests that you havent had a recent COVID-19 infection. 2021 Sep 27;12:728021. doi: 10.3389/fimmu.2021.728021. November 6, 2020. https://www.fda.gov/news-events/press-announcements/coronavirus-covid-19-update-fda-authorizes-first-test-detects-neutralizing-antibodies-recent-or. September 23, 2020. https://www.uofmhealth.org/health-library/hw41342. Many of these are available by post. The antibodies your immune system makes if you've had COVID-19 in the past are not the same as the antibodies your immune system makes after you've been vaccinated. COVID-19 Antibody Test Selection Guide Considerations Negative antibody results in persons collected earlier than 21 days after symptom onset may be negative due to the kinetics of seroconversion, specifically, some patients will not have measurable antibody until more than 21 days after symptom onset. A positive antibody test result can help identify someone who has had COVID-19 in the past or has been vaccinated against COVID-19. You should wait at least two weeks after a one-dose vaccine or two weeks after the final shot of a two-dose vaccine to get an antibody test so your body has the chance to produce detectable antibodies. 2021 Aug;21(8):1107-1119. doi: 10.1016/S1473-3099(21)00127-4. The results, which need to be confirmed in large, diverse populations, may point to a strategy to stretch the currently limited supply of vaccines against . Choose from 12 allied health programs at School of Health Professions. Clipboard, Search History, and several other advanced features are temporarily unavailable. For some vaccines that have been in use for a much longer period of time, we have a better idea of which antibody levels correlate with protection.. Review your results with a network of physicians (PWNHealth), Request the test either in-person or via a telehealth service. 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. SARS-CoV-2 antibody or serology tests look for antibodies in a blood sample to determine if an individual has had a past infection with the virus that causes COVID-19. 2021;5(543):4549. Ungtrakul T, Sornsamdang G, Soonklang K, Saeloo S, Wittayasak K, Suptawiwat O, Pulmanausahakul R, Phattraprayoon N, Auewarakul C, Mahanonda N. Public Health Pract (Oxf). Sample-to-Answer Immuno-Magnetic Assay Using Thermally Responsive Alkane Partitions. It may also mean your bodys immune system has generated a response to a prior COVID-19 infection. Keywords: Many research studies (including the clinical trials for the COVID-19 vaccine), have used these tests to look specifically at neutralizing antibodies, since these antibodies can block (neutralize) virus particles preventing them from binding to and infecting your cells. Thats why the U.S. Centers for Disease Control and Prevention (CDC) and the American College of Rheumatology (ACR) do not recommend getting an antibody test after receiving the vaccine to assess immunity.