International Journal of Hematology and Oncology 2025, Vol 35, Num 2 Page(s): 131-149
Evaluating the Reciprocal Effects of COVID-19 Vaccines and Immunotherapy on Oncology Patients Receiving Immunotherapy

Arif Hakan ONDER1, Kubra Demir ONDER2, Yesim CEKIN3, Banu OZTURK1, Erdal KURTOGLU4

1Health Sciences University Antalya Training and Research Hospital, Department of Medical Oncology
2Health Sciences University Antalya Training and Research Hospital, Department of Infectious Diseases and Clinical Microbiology
3Health Sciences University Antalya Training and Research Hospital, Department of Microbiology
4Health Sciences University Antalya Training and Research Hospital, Department of Hematology

Keywords: COVID 19 vaccines, Immunotherapy, Lymphocyte counts
The administration of immunotherapy and coronavirus disease (COVID-19) vaccines can concurrently enhance systemic immune responses. Consequently, it is hypothesized that this potential overlapping immunological enhancement from the two treatments may result in an increased occurrence of immune-related adverse events. This study aimed to demonstrate the reciprocal effects of COVID-19 vaccines and immunotherapies. In this prospective study, the type and number of COVID-19 vaccines, levels of vaccineinduced antibodies, lymphocyte subtype counts, oncological treatments, response to immune therapy, adverse events, and involvement of lymph nodes (LN) were evaluated in cancer patients and healthy volunteers. Patients who received the BioNTech vaccine regimen had a higher rate of partial response to immune therapy at 3 months. There was no significant difference in the mean vaccineinduced antibody levels between the patient and control groups. In predicting mortality, pre- and post-vaccination CD20+ lymphocyte counts, post-vaccination C-reactive protein and lactate dehydrogenase levels, total lymphocyte count, albumin level, and LN size were significant (p= 0.011, p< 0.001, p= 0.005, p= 0.003, p= 0.001, p< 0.001, and p= 0.001, respectively). In this study, the relationship between peripheral blood T and B lymphocytes, immune responses, and adverse events were clearly demonstrated. Despite the majority of patients receiving inactivated vaccines as their first dose, the absence of significant differences in antibody levels between the patient and healthy volunteer groups highlights the influence of immunotherapy on the vaccine response. The group receiving the BioNTech vaccine exhibited better treatment response results at 3 months post-vaccination than the group without BioNTech. The types of adverse events displayed distinct changes in peripheral lymphocyte counts.