Response to COVID‐19 vaccination in patients on cancer therapy: Analysis in a SARS‐CoV‐2‐naïve population

Abstract

AbstractBackgroundCancer patients have increased morbidity and mortality from COVID‐19, but may respond poorly to vaccination. The Evaluation of COVID‐19 Vaccination Efficacy and Rare Events in Solid Tumors (EVEREST) study, comparing seropositivity between cancer patients and healthy controls in a low SARS‐CoV‐2 community‐transmission setting, allows determination of vaccine response with minimal interference from infection.MethodsSolid tumor patients from The Canberra Hospital, Canberra, Australia, and healthy controls who received COVID‐19 vaccination between March 2021 and January 2022 were included. Blood samples were collected at baseline, pre‐second vaccine dose and at 1, 3 (primary endpoint), and 6 months post‐second dose. SARS‐CoV‐2 anti‐spike‐RBD (S‐RBD) and anti‐nucleocapsid IgG antibodies were measured.ResultsNinety‐six solid tumor patients and 20 healthy controls were enrolled, with median age 62 years, and 60% were female. Participants received either AZD1222 (65%) or BNT162b2 (35%) COVID‐19 vaccines. Seropositivity 3 months post vaccination was 87% (76/87) in patients and 100% (20/20) in controls (p = .12). Seropositivity was observed in 84% of patients on chemotherapy, 80% on immunotherapy, and 96% on targeted therapy (differences not satistically significant). Seropositivity in cancer patients increased from 40% (6/15) after first dose, to 95% (35/37) 1 month after second dose, then dropped to 87% (76/87) 3 months after second dose.ConclusionMost patients and all controls became seropositive after two vaccine doses. Antibody concentrations and seropositivity showed a decrease between 1 and 3 months post vaccination, highlighting need for booster vaccinations. SARS‐CoV‐2 infection amplifies S‐RBD antibody responses; however, cannot be adequately identified using nucleocapsid serology. This underlines the value of our COVID‐naïve population in studying vaccine immunogenicity.