SARS-CoV-2 seroprevalence among patients with cancer and healthcare workers from an oncology referral center during the first year of COVID-19 vaccination in Mexico

ABSTRACT

Background. Cancer patients (CPs) with COVID-19 have an increased risk of adverse outcomes. In addition, CPs seem to have a lower immune response to SARS-CoV-2 vaccination. This study aimed to evaluate SARS-CoV-2 spike antibodies (anti-S Abs) following COVID-19 vaccination in CPs and healthcare workers (HCWs). Methods. We conducted a point-seroprevalence study in CPs and HCWs who received a two-dose scheme with either BNT162b2, AZD1222, or Sputnik-V vaccine. We measured anti-S Abs by quantitative immunoassay to assess humoral immune response. Besides, we quantified anti-nucleocapsid antibodies in a subgroup of individuals to determine prior infection. We compared anti-S Abs titers in both groups and stratified by vaccine type, prior infection, and clinical characteristics. We conducted a multivariate logistic regression to determine variables associated with a poor humoral response. Results. Six hundred forty-one individuals were included 174 (27%) CPs and 467 (73%) HCWs. The median anti-S Abs titter was higher among HCWs compared to CPs (2568 U/mL vs. 1807 U/mL, p=0.002). Both CPs and HCWs with prior infection had higher anti-S Abs titter (p< 0.001). Regardless of the time since vaccination, a higher proportion of subjects with titers < 250 U/mL was observed in CPs (p< 0.001) (Fig 2). In the multivariate analysis, older age (p=0.036), AZD1222 (p=0.003), and Sputnik-V (p=0.020) were associated with lower humoral response among the entire cohort. SARS-CoV-2 spike antibody titers among cancer patients and healthcare workers. Global differences in anti-S Abs titers between CPs and HCWs groups (a) and antibody titers in CPs and HCWs groups stratified by type of received vaccine (b). Abbreviations CP Cancer patients, HCW Healthcare workers. SARS-CoV-2 spike antibody titers according to time since vaccination among cancer patients and healthcare workers. Abbreviations CP Cancer patients, HCW Healthcare workers. Conclusion. In this study, both CPs and HCWs showed an adequate response to vaccination;however, CPs had lower anti-S Abs titers and a faster decline over time. Based on our results, new strategies should be assessed to sustain the humoral response to vaccination and thus decrease the COVID-19 burden among the oncologic population.