Association of SARS-CoV-2 Spike Protein Antibody Vaccine Response with Infection Severity in Patients with Cancer: A National COVID Cancer Cross-sectional Evaluation

Abstract

Importance: Accurate identification of patient groups with the lowest level of protection following COVID-19 vaccination is important to better target resources and interventions for the most vulnerable populations. It is not known whether SARS-CoV-2 antibody testing has clinical utility for high-risk groups, such as people with cancer. Objective: To evaluate whether spike protein antibody vaccine response (COV-S) following COVID-19 vaccination is associated with the risk of SARS-CoV-2 breakthrough infection or hospitalization among patients with cancer. Design, Setting, and Participants: This was a population-based cross-sectional study of patients with cancer from the UK as part of the National COVID Cancer Antibody Survey. Adults with a known or reported cancer diagnosis who had completed their primary SARS-CoV-2 vaccination schedule were included. This analysis ran from September 1, 2021, to March 4, 2022, a period covering the expansion of the UK's third-dose vaccination booster program. Interventions: Anti-SARS-CoV-2 COV-S antibody test (Elecsys; Roche). Main Outcomes and Measures: Odds of SARS-CoV-2 breakthrough infection and COVID-19 hospitalization. Results: The evaluation comprised 4249 antibody test results from 3555 patients with cancer and 294230 test results from 225272 individuals in the noncancer population. The overall cohort of 228827 individuals (patients with cancer and the noncancer population) comprised 298479 antibody tests. The median age of the cohort was in the age band of 40 and 49 years and included 182741 test results (61.22%) from women and 115737 (38.78%) from men. There were 279721 tests (93.72%) taken by individuals identifying as White or White British. Patients with cancer were more likely to have undetectable anti-S antibody responses than the general population (199 of 4249 test results [4.68%] vs 376 of 294230 [0.13%]; P