Serologic Response to COVID-19 Infection and/or Vaccine in Cancer Patients on Active Treatment

Abstract Background It was shown that immunocompromised patients have significantly reduced immunologic responses to COVID-19 vaccines. The immunogenicity of COVID-19 vaccine/infection in patients with solid tumors is reduced. We evaluated the immunologic response to COVID-19 and/or the BNT162b2 mRNA COVID-19 vaccine among cancer patients on active treatments and reviewed previous literature to identify subgroups that may require third vaccination. Patients and methods Anti-SARS-CoV-2 S1/S2 antibodies were measured in a cohort of 202 cancer patients on active treatment with chemotherapy (96), immunologic (52), biologic (46), and hormonal (12) treatments for early (n=66, 32.7%) or metastatic disease (n=136, 67.3%). Of those, 172 had received two vaccine doses, and 30 had COVID-19 infection (20/30 also received one dose of vaccine). Specific anti–S receptor-binding domain (RBD) antibodies were further measured in patients with equivocal anti S1/S2 results. Results Among cancer patients, the SARS-CoV-2 antibody response rate was 89.1% (180/202) after COVID-19 vaccination or infection and 87.2% (150/172) in patients after vaccination without a history of COVID-19, compared with 100% positive serologic tests in a control group of 30 healthcare workers (p 60 AU/ml) was more likely with immunotherapy (odds ratio 2.44) and less likely with chemotherapy (odds ratio 0.39). Conclusions Overall, both COVID-19 vaccine and natural infection are highly immunogenic among cancer patients. However, our study identifies those under chemotherapy as significantly less responsive, and with lower antibody levels. These findings justify close virological and serological surveillance along with consideration of these patients for booster (3rd dose) vaccine prioritization, as new highly spreading SARS-CoV-2 variants emerge.