The following article features coverage from the European Society of Medical Oncology (ESMO) Congress 2021. Click here to read more of Hematology Advisor’s conference coverage.

According to the results of a study presented at the European Society for Medical Oncology (ESMO) Congress 2021, anti-SARS-CoV-2 antibody levels and their time-course pattern after COVID-19 vaccination were substantially influenced by SARS-CoV-2 infection prior to vaccination in both patients with cancer and healthy volunteers, and patients with cancer achieved levels of anti-spike protein (S) antibodies that were comparable to those of healthy volunteers 3 months after the second vaccine dose.

The findings, presented by Radka Obermannova, MD, PhD, of the Masaryk Memorial Cancer Institute in the Czech Republic, are from CoVigi, an ongoing, prospective, open-label, multicenter phase 4 clinical study evaluating the post-authorization effectiveness and safety of COVID-19 vaccines in patients receiving anticancer therapy (EudraCT Number: 2021-000566-14). The trial was initiated on March 22, 2021.

The preliminary results included SARS-CoV-2-specific immune responses, specifically detectable anti-S and antinucleocapsid protein (N) SARS-CoV-2 antibodies and lymphocyte responses evaluated by interferon (INF)-gamma level and CD69 expression. Measurements are conducted at baseline (prior to the vaccination), prior to the second vaccine dose, 4 to 8 weeks, and 3, 6, and 12 months after the first vaccine dose.

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Patients with solid tumors or hematologic malignancies receiving anticancer therapy included those treated with chemotherapy with or without monoclonal antibodies, monoclonal antibodies, checkpoint inhibitors, oral targeted treatment, and curative radiotherapy. The reference cohort comprised healthy volunteers.

The study included 213 patients with solid tumors, 97 patients with hematologic malignancies, and 76 healthy volunteers; participants completed vaccination with COVID-19 vaccines from Pfizer-BioNTech (≥98%), AstraZeneca, Johnson & Johnson, or Moderna.

According to participants’ medical history, 15% of those with solid tumors, 21% of those with hematologic malignancies, and 26% of healthy volunteers had experienced prior COVID-19 infection. According to quantitative analyses prior to vaccination, approximately 1/3 of participants in each group had detectable anti-SARS-CoV-2 antibodies, indicating that a substantial number of patients with cancer had SARS-CoV-2 infection during active anticancer treatment prior to vaccination likely with an asymptomatic course.

Among SARS-CoV-2-recovered patients with cancer prior to vaccination, the SARS-CoV-2-specific T-cell response (IFN-gamma level upon both CD4 and CD8 stimulation) was 0.04 pg/ml (interquartile range [IQR], 0.01-0.13) and natural killer T cell (NKT)-like response (increase in CD69 on NKT-like upon stimulation) was 10.9% (IQR, 6.6-17.3). Whereas, in patients with cancer who did not have prior SARS-CoV-2 infection, the SARS-CoV-2-specific T-cell response was 0.00 pg/ml (IQR, 0.00-0.01) and the NKT-like response was 7.5% (IQR, 4.0-10.1; P=.079).

Among all groups, the anti-S antibody response peaked approximately 2 months after the first vaccine dose. Overall, the anti-S antibody response after the first vaccine dose was greatly enhanced in individuals who had recovered from prior SARS-CoV-2 infection compared with those who were SARS-CoV-2 naive.

Most patients with cancer reached detectable anti-S antibodies between 28 and 58 days after the first vaccine dose (solid tumor group: 95%; hematologic malignancy group: 88%; healthy volunteers: 100%). According to the presenter, all patients with cancer achieved detectable anti-S antibodies by 3 months after the first vaccine dose and reached levels of anti-S antibodies that were comparable to those of healthy volunteers after the second vaccine dose (P =.456). Among SARS-CoV-2-naive individuals, patients with cancer had significantly lower levels of anti-S antibody after the second vaccine dose compared with healthy volunteers (P <.001 ).

Read more of Hematology Advisor’s coverage of ESMO 2021 by visiting the conference page.


Obermannova R, Demlova R, Selingerova I, et al. CoVigi phase IV multicentric trial evaluating COVID-19 vaccination adverse events and immune response dynamics in cancer patients: First results on antibody and cellular immunity. Presented at: European Society for Medical Oncology (ESMO) Congress 2021; September 16-21, 2021. Abstract 1563MO.