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Ask the Doctor: I am assuming that my COVID-19 spike protein antibody results of >2,500 means that I had a good response to the J&J COVID-19 vaccine and now have some protection?

This content was current as of the date it was released. In science and medicine, information is constantly changing and may become out-of-date as new data emerge.


In February and March 2021, I received both doses of the Moderna vaccine 21 days apart.  On 5/11/2021 as part of the LLS study of blood cancer patients’ response to vaccines, I took the antibody tests.  I had a weak response of 104 on the Spike protein test. Three weeks ago, I got the single-dose J&J vaccine and yesterday got a second antibody test.  The results are attached. I am assuming that the results of >2,500 means that I had a good response to the J&J and now have some protection.  Please let me know if my assumption is correct.  I am concerned that the Spike protein test is not accurate with the J&J vaccine which is not an mRNA vaccine against the Spike protein specifically.

Answer:  That is outstanding news for you! We are hearing anecdotal reports of similar responses with other people who have chosen to receive a booster dose and “mixed” vaccine types. Unfortunately, we cannot officially report out anything on that just yet until there are actual data to share. But good for you!

 Keep in mind that while we know that the greater the number equates to more antibodies, at this time we do not fully understand what the target number is that might equate to protection in CLL patients. So, CLL Society is still urging everyone with CLL, regardless of antibody status, to continue wearing a mask in all situations. Also, please continue to adhere closely to social distancing, and keep up with diligent hand hygiene efforts, especially now that the general population is unmasking after the latest CDC guidelines. We also strongly urge you to have household members vaccinated if possible. We would encourage you to check out Dr. Byrd’s opinion piece that was just posted on our website here.

The true interpretation of the Spike antibody test will become known over time as we learn the association between these results and how it correlates to the chance of still getting infected with COVID in the near future. There are currently many researchers with expertise in blood cancer who are looking at this very subject and performing studies. We should be hearing more about this subject in the coming months.

Here are several recent links that were just written to keep in mind regardless of vaccination status: