A Prospective Study Evaluating the Serological Profile of the Novel Coronavirus (COVID-19) Vaccines in Cancer Patients

Background: Immune-correlates of vaccine-induced immunity that can reliably predict the effectiveness of vaccines in real-world scenarios are desirable. The assessment of immunological measurements such as antibody levels have been used to detect chronic infections, previous infections and protective immunity against future infections including those derived from vaccines. We conducted a prospective study evaluating the antigenicity of COVID-19 vaccine and serological profile of cancer patients who received the BNT162b2 (Pfizer-BioNTech) or mRNA-1273 (Moderna COVID-19 vaccines.

Methods: The study was approved by Ascension St. John Hospital IRB. We assessed four cohorts: Cohort A with active solid tumor malignancies on antineoplastic agents; Cohort B with active hematological malignancies on antineoplastic therapy; Cohort C with a history of cancer and Cohort D with no history of malignancy. Each subject required completion of the primary vaccination series of SARS-CoV2 vaccines with either BNT162b2 or mRNA-1273 without a previously documented or suspected SARS-CoV2 infection at the time of enrollment. Blood samples were collected for all the study patients for the analysis of serological profile between 3-8 months of the second dose of a SARS-CoV2 vaccine.

The samples were batch processed to measure the levels of antibodies against SARS-CoV-2 spike (trimer) protein utilizing enzyme-linked immunosorbent assay (ELISA). Additionally, the levels of antibodies against SARS-CoV-2 spike (trimer), S1 subunit, S2 subunit, S1-receptor binding domain (RBD), and nucleocapsid were qualitatively assessed using SARS-CoV-2 Multi-Antigen Serology Module for Wes System (Protein Simple, CA). Data were analyzed using Student’s t-test, analysis of variance, chi-squared analysis and the Mann-Whitney U test.

Results: We enrolled 116 patients, with 37 in cohort A, 17 in cohort B, 13 in cohort C and 49 in cohort D. All cohorts were comparable with respect to mean age, mean BMI, sex and race. Table 1 shows mean antibody titers for all cohorts. Cohort B had the lowest antibody titer. Cohort A has the highest antibody titers including the nucleocapsid antibody titer which is suggestive of high rate of asymptomatic COVID-19 infection in this cohort. Antibody comparison data for cohorts A, C and D are presented in table 2. There was no statistically significant difference in antibody response between patients with solid tumor malignancy on antineoplastic agents as compared to patients without a history of cancer. A statistically significant difference in antibody response was only noted for the S1 subunit between cohorts A and C.

Conclusions: Patients with active cancer on antineoplastic agents at the time of vaccination or with prior history of cancer not on antineoplastic treatment at the time of vaccination have equivalent antibody response when compared to patients without history of cancer. It is possible that patients with solid tumor malignancy on anticancer treatment have a higher rate of asymptomatic infection.

Acknowledgements: This research is being supported by Sr. Verenice McQuade Endowment for Cancer Research. We thank our patients, research department, phlebotomists and clinical staff at Van Elslander Cancer Center for their assistance in conducting the study.