TY - JOUR
T1 - Predicting the protective humoral response to a SARS-CoV-2 mRNA vaccine
AU - Meschi, Silvia
AU - Matusali, Giulia
AU - Colavita, Francesca
AU - Lapa, Daniele
AU - Bordi, Licia
AU - Puro, Vincenzo
AU - Leoni, Bruno D.
AU - Galli, Claudio
AU - Capobianchi, Maria Rosaria
AU - Castilletti, Concetta
N1 - Funding Information:
Research funding: The study was performed in the framework of the SARS-CoV-2 surveillance and response program implemented by the Lazio Region Health Authority. This study was supported by funds to the Istituto Nazionale per le Malattie Infettive (INMI) Lazzaro Spallanzani IRCCS, Rome (Italy), from Ministero della Salute ( Programma CCM 2020 ; Ricerca Corrente – linea 1 ; COVID-2020-12371817 ); the European Commission –the European Virus Archive – GLOBAL ( grant no. 871029 ).
Publisher Copyright:
© 2021
PY - 2021/9/7
Y1 - 2021/9/7
N2 - Simple and standardized methods to establish correlates to vaccine-elicited SARS-CoV-2 protection are needed. An observational study on antibody response to a mRNA vaccine (Comirnaty) was performed on health care workers (V, n=120). Recovered COVID-19 patients (N, n=94) were used for comparison. Antibody response was evaluated by a quantitative anti-receptor binding domain IgG (anti-RBD) commercial assay and by virus microneutralization test (MNT), in order to establish a threshold of anti-RBD binding antibody units (BAU) able to predict a robust (≥1:80) MNT titer. Significant correlation between BAU and MNT titers was found in both V and N, being stronger in V (rs=0.91 and 0.57 respectively, p<0.001); a higher incremental trend starting from MNT titer 1:80 was observed in the V group. The 99% probability of high MNT titer (≥1:80) was reached at 1,814 and 3,564 BAU/mL, and the area under the receiver operating characteristic (ROC) curve was 0.99 (CI: 0.99-1.00) and 0.78 (CI: 0.67-0.86) in V and N, respectively. A threshold of 2,000 BAU/mL is highly predictive of strong MNT response in vaccinated individuals and may represent a good surrogate marker of protective response. It remains to be established whether the present results can be extended to BAU titers obtained with other assays.
AB - Simple and standardized methods to establish correlates to vaccine-elicited SARS-CoV-2 protection are needed. An observational study on antibody response to a mRNA vaccine (Comirnaty) was performed on health care workers (V, n=120). Recovered COVID-19 patients (N, n=94) were used for comparison. Antibody response was evaluated by a quantitative anti-receptor binding domain IgG (anti-RBD) commercial assay and by virus microneutralization test (MNT), in order to establish a threshold of anti-RBD binding antibody units (BAU) able to predict a robust (≥1:80) MNT titer. Significant correlation between BAU and MNT titers was found in both V and N, being stronger in V (rs=0.91 and 0.57 respectively, p<0.001); a higher incremental trend starting from MNT titer 1:80 was observed in the V group. The 99% probability of high MNT titer (≥1:80) was reached at 1,814 and 3,564 BAU/mL, and the area under the receiver operating characteristic (ROC) curve was 0.99 (CI: 0.99-1.00) and 0.78 (CI: 0.67-0.86) in V and N, respectively. A threshold of 2,000 BAU/mL is highly predictive of strong MNT response in vaccinated individuals and may represent a good surrogate marker of protective response. It remains to be established whether the present results can be extended to BAU titers obtained with other assays.
KW - antibody response
KW - protective immunity
KW - SARS-CoV-2
KW - vaccine
KW - viral neutralization
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U2 - 10.1515/cclm-2021-0700
DO - 10.1515/cclm-2021-0700
M3 - Article
AN - SCOPUS:85114802781
SP - 1
EP - 9
JO - Clinical Chemistry and Laboratory Medicine
JF - Clinical Chemistry and Laboratory Medicine
SN - 1434-6621
ER -