SARS-CoV-2 adaptive immunity in nursing home residents up to eight months after two doses of the Comirnaty® COVID-19 vaccine

Abstract

Burgos JS (General Directorate of Research and Healthcare Supervision, Department of Health, Valencia Government, Valencia, Spain); Meneu de Guillerna R (Vice-President Foundation Research Institute in Public Services, Valencia, Spain); Vanaclocha Luna H (General Directorate of Public Health, Department of Health, Valencia Government, Valencia, Spain); Burks DJ (The Prince Felipe Research Center-CIPF-, Valencia, Spain; Cervantes A (INCLIVA Health Research Institute, Valencia, Spain); Comas I (Biomedicine Institute of Valencia, Spanish Research Council (CSIC); Díez-Domingo J (Foundation for the promotion of health and biomedical research of the Valencian Community-FISABIO-, Valencia, Spain); Peiro S (Foundation for the promotion of health and biomedical research of the Valencian Community-FISABIO-, Valencia, Spain); González-Candelas F (CIBER in Epidemiology and Public Health, Spain; Joint Research Unit "Infection and Public Health" FISABIO-University of Valencia, Valencia, Spain; Institute for Integrative Systems Biology (I2SysBio), CSIC-University of Valencia, Valencia, Spain); Ferrer Albiach C (Fundación Hospital Provincial de Castelló); Hernández-Aguado I (University Miguel Hernández, Alicante, Spain); Oliver Ramírez N (DataPop Alliance); Sánchez-Payá J (Preventive Medicine Service, Alicante General and University Hospital, Alicante, Spain; Alicante Institute of Health and Biomedical Research (ISABIAL), Alicante, Spain; Vento Torres M (Instituto de Investigación Sanitaria La Fe); Zapater Latorre E (Fundación Hospital General Universitario de València); Navarro D (Microbiology Service, Clinic University Hospital, INCLIVA Health Research Institute, Valencia, Spain;Department of Microbiology, School of Medicine, University of Valencia, Valencia, Spain).

Keywords: Comirnaty® COVID-19 vaccine; SARS-CoV-2; SARS-CoV-2-S T cells; SARS-CoV-2-S antibodies; nursing home residents.

Fig. 1

SARS-CoV-2 antibody and T-cell immunity in nursing home residents up to eight months after two doses of the Comirnaty® COVID-19 vaccine. (A) SARS-CoV-2-Spike IgG reactivity of plasma from SARS-CoV-2-naïve and experienced nursing home residents at a median of 7 months after full vaccination with the Comirnaty® vaccine, as determined by the OnSite COVID-19 IgG/IgM Rapid immunochromatography Test (CTK BIOTECH, Poway, CA, USA). The IgG line intensity was scored visually using a 4‐level scale as previously reported: 0 = negative result; 1+ = intensity of test band lower than control band; 2+ = intensity of test band equal to control line; 3+ = intensity of test band greater than control line. (B) SARS-CoV-2-Spike total antibody levels as measured by Roche Elecsys® assay (Roche Diagnostics, Pleasanton, CA, USA) in paired plasma specimens collected from 100 either SARS-CoV-2-naïve or -experienced nursing home residents at a median of 3 months (3 M) and 7 months (7 M) after full Comirnaty® vaccination. Both assays are calibrated to the WHO International Standard and Reference Panel for anti-SARS-CoV-2 antibody and provide quantitative values that strongly correlate with SARS-CoV-2 neutralizing antibody titers . (C) SARS-CoV-2-Spike-reactive IFNγ‐producing CD4⁺ and CD8⁺ T cells, as enumerated by flow cytometry for intracellular staining in paired whole-blood specimens collected from 24 nursing home residents at a median of 3 months (3 M) and 7 months (7 M) after full Comirnaty® vaccination. Differences between medians were compared using the Mann–Whitney U test or the Wilcoxon test, as appropriate. Two-sided exact P-values are reported. A P-value <0.05 was considered statistically significant. The analyses were performed using SPSS version 20.0 (SPSS, Chicago, IL, USA).