key: cord-0881224-v5eth1m3
authors: Bradley, T.; CODIEFY study team,; Grundberg, E.; Selvarangan, R.
title: Antibody responses boosted in seropositive healthcare workers after single dose of SARS-CoV-2 mRNA vaccine
date: 2021-02-05
journal: medRxiv : the preprint server for health sciences
DOI: 10.1101/2021.02.03.21251078
sha: 29aa93db7676ba5b18d769b5af8e527d25a30ea7
doc_id: 881224
cord_uid: v5eth1m3

Current guidelines recommend that individuals who have had COVID-19 should receive the identical vaccine regimen as those who have not had the infection. This includes two doses of the mRNA platform vaccines (BNT162b2/Pfizer; mRNA-1273/Moderna) that are approved for use in the United States. In this brief report, we show that after a single dose of the Pfizer SARS-CoV-2 vaccine, individuals that had prior SARS-CoV-2 infection had significantly higher antibody levels than individuals that had no history of infection. This provides the rationale for changing vaccination policy to deliver only a single dose to individuals with recent SARS-CoV-2 infection that may free up additional doses for individuals that have no preexisting immunity to the virus. Future study of other immune parameters such as T cell response and durability of immune response should be rapidly undertaken in individuals that had COVID-19 prior to vaccination.

Here we determined antibody levels at baseline and 3 weeks after the first vaccine dose of the Pfizer BNT162b2 SARS-CoV-2 mRNA vaccine in healthcare workers with laboratory confirmed SARS-CoV-2 infection 30-60 days prior to vaccine (COVID19+; N=36) or workers without history of infection (COVID19-;N=152). Using a multiplex bead binding assay (Millipore #HC19SERG1-85K) that measures IgG levels against SARS-CoV-2 spike protein subunits S1, S2, Receptor Binding Domain (RBD) and the nucleocapsid protein (NP), we found that after the 1 st vaccine dose, both COVID19-and COVID19+ individuals antibody titers were enhanced to all proteins with the exception of NP which is not a vaccine antigen (P<0.0001, Wilcoxon-Mann-Whitney; Figure 1A ). At baseline, we observed 6 individuals that had antibody levels that matched COVID-19 seropositive status and may have had undiagnosed infection. Namely, having MFI ≥1000 for the S1 protein. We separated these individuals from analysis (Undiagnosed) and found that they resembled the COVID19+ in the week 3 serology assays. After the first vaccine dose COVID19+ individuals had significantly higher antibody titers to the S1, S2 and RBD compared to COVID19-individuals (P<0.0001, All rights reserved. No reuse allowed without permission.

(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted February 5, 2021. ; https://doi.org/10.1101/2021.02.03.21251078 doi: medRxiv preprint NOTE: This preprint reports new research that has not been certified by peer review and should not be used to guide clinical practice.

Wilcoxon-Mann-Whitney). As a proxy for measuring virus neutralizing antibodies, we utilized an FDA approved in vitro assay that allows qualitative detection of SARS-CoV-2 neutralizing antibodies in the blood (Genscript, #L00847; Figure 1B ). We found that neutralizing antibodies were boosted for the COVID19+ individuals (median 48.6% blocking at baseline and median 96.3% blocking at week3; P<0.0001, Wilcoxon-Mann-Whitney). While COVID19-individuals neutralizing antibodies were also boosted after vaccination (median 8.9% blocking at baseline and median 59.5% blocking at week3) they were significantly lower than the COVID19+ individuals (P<0.0001, Wilcoxon-Mann-Whitney).

These findings suggest that in individuals with recent SARS-CoV-2 infection or seropositive status elicit a more rapid booster antibody response to vaccination and provides a rationale for considering a single dose vaccine regimen in this population. The duration of antibody responses also will need further investigation.

The vaccinee biospecimens were collected under a clinical study at Children's Mercy Kansas City and reviewed and approved by the Children's Mercy IRB (#00001670 and #00001317). All rights reserved. No reuse allowed without permission.

(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted February 5, 2021. ; https://doi.org/10.1101/2021.02.03.21251078 doi: medRxiv preprint

Efficacy and Safety of the mRNA-1273 SARS-CoV-2 Vaccine

Safety and Efficacy of the BNT162b2 mRNA Covid-19

Antibody Status and Incidence of SARS-CoV-2 Infection in Health Care Workers

The authors declare no conflicts of interest

We thank all the health care workers that participated in this study. Special thanks to Occupational Health and CM Research Institute for their support of this study.