Ask the Doctor Question:
I am a R/R CLL patient currently on my fifth line of treatment with venetoclax and obinutuzumab and participate in the LLS COVID antibody research study. I received my second dose of the Pfizer vaccine in March, and a third dose in September. One-month after my second dose, antibodies against the SARS-CoV-2 spike protein receptor binding domain were detected, but only at a level of 0.85, barely above the positive threshold of 0.80. The nucleocapsid test was negative. Four-months later, before the third dose, the spike protein antibodies increased slightly to 2.7; the nucleocapsid test again was negative. One-month after the third dose, the spike protein antibodies jumped way up to 747.6, and the nucleocapsid test was positive. I’ve never had any COVID symptoms and, except for medical appointments, am never inside anywhere with people outside my family and never unmasked. I get IVIG every 6 weeks and had an infusion 1 week before this latest blood test. Is it possible that the IVIG affected one or both of these recent blood test results, especially the positive nucleocapsid result? That is, might the IVIG donor have had COVID and produced antibodies that were transferred to me in the IVIG? Could this also apply to the spike protein antibodies from the donor’s vaccination?
Answer: You are exactly spot on. IVIG is made by pooling immunoglobulins from thousands of donors. Anecdotally we have heard of a couple of CLL patients who have also had a positive nucleocapsid COVID test who were receiving IVIG (also who have been extremely careful and never had any COVID symptoms). As more and more people in the US have come down with COVID, that pool of people is incrementally having an increasing number of people who have COVID antibodies which can turn the nucleocapsid test positive.
However, the quantitative antibody level jumping to 747 is most likely all you! There is no evidence that spike protein antibodies transfer. If that were the case, then everyone who receives a blood transfusion from those with adequate antibody levels would have robust immunity, but that has not been shown to be the case.
A good response to the third dose/booster is a pretty common finding we are hearing anecdotally from many CLL patients (that their booster took them from next to nothing to a much higher number) and is why the CDC has been pushing boosters for the immunocompromised community, because they do have a good chance of working.
Congratulations! We would encourage you to continue to be extremely cautious and make sure you have completed your checklists as part of forming your own personal COVID-19 Action plan. Those can be found here: https://cllsociety.org/2021/07/covid-19-plan-checklists-for-chronic-lymphocytic-leukemia-cll-preparing-for-pre-and-post-covid-19-exposure/