Clin Exp Vaccine Res.  2023 Apr;12(2):107-115. 10.7774/cevr.2023.12.2.107.

Immunogenicity of the ChAdOx1 nCoV-19 vaccine in patients with hematologic malignancies

• Thookhamme C
• Navinpipat M
• Sasakul A
• Pattarakosol P
• Lertchaisataporn K
• Tawinprai K
• Praditsuktavorn P

• KMID: 2552345
• DOI: http://doi.org/10.7774/cevr.2023.12.2.107

Abstract

Purpose
The present study aimed to study the immunogenicity of the ChAdOx1 nCoV-19 vaccine in patients with hematologic malignancies.
Materials and Methods
This prospective cohort study of hematology patients aimed to evaluate their antibody levels against the receptor-binding domain of the severe acute respiratory syndrome coronavirus 2 spike protein and seroconversion rates following two doses of the ChAdOx1 nCoV-19 vaccine. Between June and July 2021, we enrolled 61 patients and included 44 patients in our analysis. Antibody levels were assessed 8 and 4 weeks after the first and second injections, respectively, and compared with those of a healthy group.
Results
Eight weeks after the first dose, the geometric mean antibody level was 1.02 binding antibody units (BAU)/mL in the patient group and 37.91 BAU/mL in the healthy volunteer group (p<0.01). Four weeks after the second dose, the geometric mean antibody level was 9.44 BAU/mL in patients and 641.6 BAU/mL in healthy volunteers (p<0.01). The seroconversion rates 8 weeks after the first dose were 27.27% and 98.86% in the patient and healthy volunteer groups, respectively (p<0.001). The seroconversion rate 4 weeks after the second dose was 47.73% in patients and 100% in healthy volunteers. Factors leading to lower seroconversion rates were rituximab therapy (p=0.002), steroid therapy (p<0.001), and ongoing chemotherapy (p=0.048). Factors that decreased antibody levels were hematologic cancer (p<0.001), ongoing chemotherapy (p=0.004), rituximab (p<0.001), steroid use (p<0.001), and absolute lymphocyte count <1,000/mm³ (p=0.009).
Conclusion
Immune responses were impaired in individuals with hematologic malignancies, particularly patients undergoing ongoing therapy and B-cell-depleting therapy. Additional vaccinations should be considered for these patients, and further investigated.

Keyword

ChAdOx1 nCoV-19 vaccine; SARS-CoV-2 virus; COVID-19 vaccine; COVID-19 virus