A Single Dose of BNT162b2 Messenger RNA Vaccine Induces Airway Immunity in Severe Acute Respiratory Syndrome Coronavirus 2 Naive and Recovered Coronavirus Disease 2019 Subjects

Abstract

Background Mucosal antibodies can prevent virus entry and replication in mucosal epithelial cells and hence virus shedding. Parenteral booster injection of a vaccine against a mucosal pathogen promotes stronger mucosal immune responses following prior mucosal infection compared to injections of a parenteral vaccine in a mucosally naive subject. We investigated whether this was also the case for the BNT162b2 COVID-19 mRNA vaccine. Methods Twenty recovered COVID-19 subjects (RCS) and 23 SARS-CoV-2 naive subjects were vaccinated with respectively one and two doses of the BNT162b2 COVID-19 vaccine. Nasal Epithelial Lining Fluid (NELF) and plasma were collected before and after vaccination and assessed for Immunoglobulin (Ig)G and IgA antibody levels to Spike and for their ability to neutralize binding of Spike to ACE-2 receptor. Blood was analyzed one week after vaccination for the number of Spike-specific Antibody Secreting Cells (ASCs) with a mucosal tropism. Results All RCS had both nasal and blood SARS-CoV-2 specific antibodies at least 90 days after initial diagnosis. In RCS, a single dose of vaccine amplified pre-existing Spike-specific IgG and IgA antibody responses in both NELF and blood against both vaccine homologous and variant strains, including delta. These responses were associated with Spike-specific IgG and IgA ASCs with a mucosal tropism in blood. Nasal IgA and IgG antibody responses were lower in magnitude in SARS-CoV-2 naive subjects after two vaccine doses compared to RCS after one dose. Conclusion Mucosal immune response to the SARS-CoV-2 Spike protein is higher in RCS after a single vaccine dose compared to SARS-CoV-2 naive subjects after two doses.

Multiplex Hybrid Antigen-Capture LC-MRM Quantification in Sera and Nasal Lining Fluid of AZD7442, a SARS-CoV-2-Targeting Antibody Combination

“…However, analyses of drug concentrations in NLF have been hindered by a lack of convenient, reliable sampling methods (e.g., swabs or nasal lavage) that yield low analyte concentrations which, in turn, produce broad reported ranges for the partition ratio of biopharmaceuticals into the nasopharynx. Common methods for mAb bioanalysis in NLF consist of ELISA, ,− electrochemiluminescence, , bead-based antibody assays, , and other commercially available serological assays . Generally, the ELISA assays were semiquantitative, , intended for research purposes only (with manufacturer reported range of 250–16,000 pg/mL), or reported standard curve in the ng/mL range (0.195–200 ng/mL) .…”

“…Similarly, a highly sensitive LBA-LC-MS/MS-based assay was developed and qualified for the absolute quantification of the two mAbs in human NLF. NLF is a hitherto under-evaluated matrix gaining interest as a patient-centric matrix in studies of COVID-19, ,,, and other respiratory diseases. − …”

“…Common methods for mAb bioanalysis in NLF consist of ELISA, 10 , 35 − 37 electrochemiluminescence, 38 , 39 bead-based antibody assays, 40 , 41 and other commercially available serological assays. 42 Generally, the ELISA assays were semiquantitative, 36 , 37 intended for research purposes only (with manufacturer reported range of 250–16,000 pg/mL), 35 or reported standard curve in the ng/mL range (0.195–200 ng/mL). 10 The sensitivity of the bead-based antibody assays varied by analyte with the lower limit of quantification [LLOQ] for interleukin [IL]-5 being 0.27 pg/mL 41 and the lower limit of detection [LLOD] being 2.0 pg/mL for IL-5.…”

Escape of SARS-CoV-2 variant Omicron to mucosal immunity in vaccinated subjects

“…Data were acquired on the V-PLEX® Sector Imager 2400 plate reader and analyzed using Discovery Workbench 3·0 software. NELF antibodies were assessed for their ability to inhibit the binding of a soluble ACE2 to Spike of the ancestral SARS-CoV-2 strain and its Delta and Omicron variants using the multiplex V-PLEX® SARS-CoV-2 Panel 13 ACE2 Kit as described 10 . NELF were diluted 10-fold before being assessed for binding inhibition.…”

“…Serum albumin concentration in NELF was more than 100-fold lower in NELF compared to serum ruling out the possibility that collecting nasal fluids using swabs could have irritated the epithelia eventually increasing exudation of tissue fluids. IgA and IgG to Spike of the SARS-CoV-2 ancestral strain and of its Delta and Omicron variant were measured using the V-PLEX® SARS-CoV-2 Panel (MSD, Maryland, US), as described 10 . Total IgA and IgG levels were measured using the V-PLEX® Isotyping Panel 1 Human/NHP Kit.…”