About participation in Texas CARES
Is enrollment for Texas CARES still open?
We have reached enrollment goals for this portion of the program and have ended new enrollment. You can check for information about new enrollment on our website, or stay subscribed to Texas CARES texts and emails for updates.
Who can participate in Texas CARES?
Texans between the ages of 6 months and 90 years old. Anyone can continue to participate, even if you have never been tested for COVID-19 or have tested positive or negative for COVID-19 in the past. We suggest waiting at least 14 days since a positive confirmed COVID-19 viral test before getting your antibody test. You can participate even if you have been vaccinated or plan to receive the vaccine soon. Learning about the levels of antibodies in many different people provides critical information about potential protection from COVID-19.
Why should I continue to participate in Texas CARES?
Getting tested will help Texans understand how many people may have had COVID-19 and did not show symptoms, how many Texans currently have COVID-19 antibodies (either from infection or vaccination), and how long the antibodies will last. It may also help us to better understand long COVID-19, which some people experience.
Can I participate if I have received or plan to receive a COVID-19 vaccine booster?
Yes! For the most accurate antibody test results, it is best to wait at least 14 days after your booster to get your antibody test.
Can I continue to participate if I am already enrolled in another study?
Yes, you can still participate in the Texas CARES program if you are already enrolled in another study.
How long should I wait to complete my antibody test at CPL after I test positive for COVID-19?
We suggest waiting at least 14 days after a positive COVID-19 viral test before completing your antibody test. Antibodies may not be present among those tested early in the infection, which may result in a negative N-test.?
How Texas CARES works
Why are there multiple antibody tests?
Texas CARES is a survey that aims to identify potential protection from future COVID-19 infection provided by antibodies that your body develops in response to a COVID-19 infection or the vaccine. Texas CARES is designed to examine how long those antibodies remain in participants over time with a survey and antibody test every three months.
How will I know when to get my next antibody test?
The survey is designed to test participants at multiple time points, about three months apart. Here is how it works:
- You will receive a text reminder with a personalized link to your next survey three months after your previous results were received.
- Once you complete your new survey, you will receive a text with your new order number to take to CPL for your next antibody test.
We ask that all participants take their test as close to the three-month mark as possible. Please email us at firstname.lastname@example.org and include your cellphone number and date of birth if you have not received your text message three months after your last antibody test.?
Note: At this time, most participants have completed four surveys and antibody tests. However, a subgroup of participants was selected to complete additional surveys and antibody tests. Stay subscribed to Texas CARES emails and texts for future updates.
I enrolled a while ago, but I haven’t participated yet. Can I still go for my first antibody test?
Unfortunately, we have closed past testing windows for the previous surveys and antibody tests, and unused orders have expired. Please check our website and social media for updates on the program, data collected, and any future opportunities for enrollment.
I have completed four antibody tests. Will I receive another survey and antibody test?
A subgroup of participants was selected to complete fifth and sixth surveys and antibody tests, about six months apart. Please check our website or social media platforms for any future updates, and stay subscribed to Texas CARES emails and texts for more information.
How do I redo my survey if anything changes after completing the survey?
If you completed your survey more than 30 days ago and have not gone for your antibody test or need to make changes to your survey due to a recent COVID-19 infection or new vaccination and/or booster, please contact Texas CARES at TexasCARES@uth.tmc.edu to?receive a new survey link.
Do I need to pay for my COVID-19 antibody test at CPL?
No, participation is free. Expenses are covered by Texas CARES.
Do I need to schedule an appointment for my antibody test?
No, but we recommend checking the hours of operation for the CPL locations near you by clicking here before going to the lab. No appointment needed.
What do I need to bring to CPL?
Your picture ID and your confirmation text, which contains your Requisition ID# 255799-XXXXXXXX
How will I get my results?
Your results (positive or negative for COVID-19 antibodies) will be texted to you 2-5 days after you get your blood drawn at CPL. You can access a full report on CPL’s portal after you receive the text message from Texas CARES. If your results are not loaded in the portal, please call the Sonic MyAccess customer service group at 844-280-8484.
Parents or guardians may create an account for their minor child, aged 17 or younger, by clicking here. As part of the registration process, you will be asked to complete, sign, and submit a Record Request (RR) form along with proper identification via email, fax or mail. Once the completed form is received and patient identity has been verified, the account will be activated, and the requester will be notified via email. For assistance with this process, please call 844-280-8484.
About your test results
What does a negative antibody test result mean?
N-test: If you get a negative result on the N-test antibody test, it means you probably haven't had the virus before. However, if you recently got infected, the test might not detect antibodies yet. In some people, the antibodies might disappear over time after being present initially. If you have COVID-19-like symptoms or are in close contact with an infected person, get a viral test done by your local public health department.
S-test: The S-test can find antibodies from either a previous COVID-19 infection or from vaccination.
Texas CARES offers up to four tests over a 12-month period so you can know how your immune response changes over time. You will receive your next survey link three months after your test, which will generate your next order number.
Read more from the CDC about antibody tests by clicking here.
What does a positive antibody test result mean?
N-test (presence of COVID-19 antibodies): If you test positive for these antibodies, it means you may have had a previous COVID-19 infection and might have some level of protection against getting a serious infection. However, it's uncertain how long this protection will last.
If you didn’t have COVID-19 symptoms but tested positive for antibodies, you are unlikely to have an active infection but may have had one in the past. You should follow general recommendations from the CDC to prevent infection with SARS CoV-2. If you had a confirmed or likely COVID-19 illness in the past, you should follow the CDC's guidance on when it's safe to resume normal activities, including work, regardless of whether you have antibodies or not.
For health care workers or first responders that test positive for SARS-CoV-2 antibodies, there should be no change in how you practice medical safety or use personal protective equipment (PPE).
Positive S-test: This test detects antibodies from a past COVID-19 infection or vaccination.
Read more from the CDC about antibody tests by clicking here.
What do my CPL test results mean?
"COVID-19 Antibodies, Spike Protein" (S-Test): detects antibodies from a past COVID-19 infection AND/OR vaccination
"SARS-CoV-2 Total Antibodies" (N-Test): detects ONLY antibodies from a past COVID-19 infection
The sample below may help interpret your results in the portal.
CPL Laboratories has recently expanded the reporting range for antibody tests. This will affect the results of S-tests, which measure the level of antibodies produced in response to a COVID-19 infection and/or a COVID-19 vaccine.
You may see the following message from CPL when you receive your results:
EXPANDED CLINICAL REPORTING RANGE OF 0.4-225,000 IU/ML
HAS BEEN VALIDATED TO REPLACE PRIOR REPORTING RANGE OF
0.4-25,000 IU/ML, EFFECTIVE 8/8/2023.
As the pandemic progressed, the levels of S-antibodies in response to infection or vaccination increased. You may have noticed that some of your previous tests listed your S-test value as 0.8-225,000 IU/mL or, with higher values, as >25,000 IU/mL. The new range will measure values up to 225,000 IU/mL. S-test values that are higher than 225,000 IU/mL will be reported as >225,000 IU/mL.
This new process for analyzing the S-antibodies will give participants an improved picture of their current antibody levels. It will not affect previous results.
We are unable to provide medical advice. Please follow up with your primary care provider if you have additional questions about your results.
What does the index number for the?"COVID-19 Antibodies, Spike Protein (Quantitative)"?(S-test)?mean?
The S-Test portion of Texas CARES' total antibody test shows the number of antibodies in your system at the time of the test, either from your COVID-19 vaccine or past infection. At this time, there is not information on what specific values mean for protection. We are not able to provide medical advice. If you have questions about your results, please consult your primary care provider.
However, you can use the S-test to:
- Confirm the presence of antibodies.
- Track your antibody level over time (range: 0.8-225,000 IU/mL) with Texas CARES' four free antibody tests.
- Contribute information through the Texas CARES survey to help the research community understand and identify the level of antibodies needed to provide protection against severe infection.
What does the "SARS-CoV-2 Total Antibodies Quantitative" (N-test) COI number mean?
The N-test cutoff index (COI) provides the reaction strength over cutoff to identify antibody presence. Texas CARES uses two tests. The N-test is a qualitative test that measures total antibody (IgM, IgG, IgA) to COVID-19 N protein. Positive results are usually associated with prior COVID-19 infection but not with vaccination alone.
COI* < 1.0 = non-reactive (or negative)
COI ≥ 1.0 = reactive (or positive)
Numeric result Result message
COI < 1.0 Non-reactive Negative for anti-SARS-CoV-2 antibodies COI ≥ 1.0 Reactive Positive for anti-SARS-CoV-2 antibodies
Information from Roche (the test manufacturer)
Interpretation of the results:
Results obtained with the Elecsys Anti-SARS-CoV-2 assay can be interpreted as follows:
The magnitude of the measured result above the cutoff is not indicative of the total amount of antibody present in the sample. The individual immune response following SARS-CoV-2 infection varies considerably and might give different results with assays from different manufacturers. Results of assays from different manufacturers should not be used interchangeably.
The COI number should not be used to judge or estimate the amount of antibodies present in the blood draw. The COI number is used to identify a positive or negative sample.
If I got the vaccine, does a negative antibody result mean the vaccine didn’t work?
No. Immune response time varies. It usually takes about two weeks after a vaccine to get an antibody response, and this timeline varies between individuals.
What COVID-19 antibody test is used?
- Roche Elecsys Anti-SARS-CoV-2 S (semi-quantitative assay that detects antibodies from vaccination or past infection).
- Roche Elecsys Anti-SARS-CoV-2 (qualitative assay that only detects antibodies from past infection).
More information about these tests:
What is the accuracy of the COVID-19 antibody test?
The accuracy of the COVID-19 antibody tests has two parts: specificity and sensitivity. With a given specificity of 99.8% for the N-test, out of 500 participants who have never had COVID-19, the test would be expected to be negative for 499 participants. The sensitivity for the N-test is close to 100% for people who had COVID-19 at least 14 days before blood draw, meaning nearly everyone who was infected becomes positive. Some people with impaired immune systems may be only weakly positive or not show a detectable antibody response at all. Also, antibody results tend to drop lower over time, and some people that were originally positive may become negative over time.
Roche Elecsys Anti-SARS-CoV-2 (natural-induced immunity)
Clinical specificity: 99.8%
Clinical sensitivity at > or = 14 days post PCR confirmation: 99.5%
Antibodies may not be present among those tested early in illness before antibodies develop or among those who never develop detectable antibodies following infection. We recommend waiting 14 days after a positive PCR COVID-19 test before getting tested for antibodies.
Roche Elecsys Anti-SARS-CoV-2 S (vaccine-induced & natural immunity)
Clinical specificity: 100%
Positive percentage agreement: at > or = 15 days post PCR confirmation: 96.6%
Negative Percent Agreement: 99.98%
Will my results be shared with anyone?
Your personal results will not be shared with your employer, organization, or academic institution.
General COVID-19 information
What is the difference between SARS-CoV-2 and COVID-19?
SARS-CoV-2 is the virus that causes COVID-19.
What is an antibody?
An antibody is a protein formed by your body in response to a specific foreign substance, such as a virus, that helps your body fight infection. The presence of antibodies in the blood can help identify a past infection. Antibodies are also produced in response to vaccination.
What is the difference between an antibody test and a viral test?
Antibody tests identify a past infection and/or a past vaccination, while viral tests identify a current viral infection.
Where can I go for updates and more information about COVID-19?
The most-up-to-date information is available on COVID-19 is available from the CDC, which you can visit by clicking here.