Abstract
Background and aim: The BNT162b2 COVID-19 vaccine (Pfizer/BioNTech), given as a two-dose series, 3 weeks apart, elicits a serological response in 84-98% of patients with cancer, even if administered while undergoing anticancer treatments. Herein, we report the impact of a third (booster) dose of BNT162b2, delivered 6 months following the second vaccine dose.
Methods: This pilot study included four patients with cancer who were seronegative after two vaccine doses, and received a third (booster) dose of BNT162b2 at 6 months following the second vaccine dose. The four patients received the three vaccine doses between December 2020 and July 2021. Samples were evaluated with an enzyme-linked immunosorbent assay (ELISA) that detects IgG (Immunoglobulin G) antibodies against the RBD (receptor-binding domain) of SARS-CoV-2.
Results: At a mean time of 19 days (ranges 7-28) after the second vaccination, all four patients were seronegative for RBD-IgG. However, at a mean time of 21 days (ranges 20-22) after the third dose, three out of the four patients (75%) were now seropositive. Mean RBD-IgG titers were increased after the third vaccine dose from 0.37 to 2.81 (Student’s t-test, p = 0.05, two-sided).
Conclusions: Although limited by the small sample size, our findings suggest that a third (booster) dose administered to patients with cancer, who remain seronegative despite two doses of BNT162b2, may be efficacious in eliciting an antibody response.
Keywords: BNT162b2; COVID-19; booster; cancer.
【저자키워드】 COVID-19, BNT162b2, booster, cancer., 【초록키워드】 SARS-CoV-2, IgG, COVID-19 vaccine, vaccine doses, antibody, Cancer, Antibody Response, ELISA, vaccine dose, BNT162b2, enzyme-linked immunosorbent assay, Immunoglobulin G, Receptor-binding domain, Immunoglobulin, Patient, seropositive, seronegative, booster, serological response, Pfizer/BioNTech, dose, student, Patients with cancer, second vaccination, pilot study, enzyme, domain, t-test, small sample size, anticancer, IgG titers, Administered, enzyme-linked immunosorbent, detect, Sample, evaluated, elicit, the RBD, of BNT162b2, two-sided, 【제목키워드】 COVID-19 vaccine, booster dose, cancer patient, of BNT162b2,