Immunogenicity of The BNT162b2 mRNA COVID-19 Vaccine in Patients With Primary Brain Tumors: A Prospective Cohort Study
Abstract Purpose Immunogenicity of Covid-19 vaccines may be negatively impacted by anti-cancer treatment. The management of primary brain tumor (PBT) patients routinely includes temozolomide and steroids, which are immune-suppressive. In this study, we aimed to determine the rate of seropositivity in PBT patients following receipt of two doses of the BNT162b2 vaccine. Methods We prospectively evaluated IgG antibody levels against SARS-CoV-2 spike protein in 17 PBT patients following two doses of the BNT162b2 mRNA vaccine. IgG levels were collected at two time points: T1 - after a median of 44 days from the second vaccine dose and T2 - after a median of 130 days from the second dose. Titers were compared against a group of healthy controls (HC) comprised of patients’ family members/caregivers. Results At T1, 88.2% (15/17) of PBT patients achieved seroconversion, compared with 100% (12/12) of HCs. Median IgG titer was significantly lower in the PBT group compared to the HC group (1,908 AU/mL vs 8,198 AU/mL, respectively; p=0.002). At T2, 80% (12/15) of PBT achieved seroconversion, compared to 100% (10/10) of the HCs. Median IgG titer remained significantly lower in the PBT group (410 vs 1687; p=0.002). All three PBT patients who failed to seroconvert at T2 had been treated with corticosteroids during vaccination. In a univariate analysis, steroid use was negatively associated with antibody titer. Conclusion Most PBT patients achieve seroconversion after receiving the BNT162b2 vaccine, but with lower IgG titer compared to HCs. Steroid use during the vaccination period is associated with lower titer.