Salivary IgG to SARS-CoV-2 indicates seroconversion and correlates to serum neutralization in mRNA-vaccinated immunocompromised individuals

Healy K, Pin E, Chen P, Söderdahl G, Nowak P, Mielke S, Hansson L, Bergman P, Smith CIE, Ljungman P, Valentini D, Blennow O, Österborg A, Gabarrini G, Al-Manei K, Alkharaan H, Sobkowiak MJ, Yousef J, Mravinacova S, Cuapio A, Xu X, Akber M, Loré K, Hellström C, Muschiol S, Bogdanovic G, Buggert M, Ljunggren HG, Hober S, Nilsson P, Aleman S, Sällberg Chen M

Med (N Y) - (-) - [2022-01-00; online 2022-01-00]

Immunocompromised individuals are highly susceptible to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Whether vaccine-induced immunity in these individuals involves oral cavity, a primary site of infection, is presently unknown. Immunocompromised patients (n=404) and healthy controls (n=82) participated in a prospective clinical trial (NCT04780659) encompassing two doses of the mRNA BNT162b2 vaccine. Primary immunodeficiency (PID), secondary immunodeficiencies caused by human immunodeficiency virus (HIV) infection, allogeneic hematopoietic stem cell transplantation (HSCT)/chimeric antigen receptor T cell therapy (CAR-T), solid organ transplantation (SOT), and chronic lymphocytic leukemia (CLL) patients were included. Salivary and serum immunoglobulin G (IgG) reactivities to SARS-CoV-2 spike were measured by multiplex bead-based assays and Elecsys® Anti-SARS-CoV-2 S assay. IgG responses to SARS-CoV-2 spike antigens in saliva in HIV and HSCT/CAR-T groups were comparable to healthy controls after vaccination. The PID, SOT, and CLL patients had weaker responses, influenced mainly by disease parameters or immunosuppressants. Salivary responses correlated remarkably well with specific IgG titers and the neutralizing capacity in serum. Receiver operating characteristic curve analysis for the predictive power of salivary IgG yielded AUC=0.95, PPV=90.7% for entire cohort after vaccination. Saliva conveys vaccine responses induced by mRNA BNT162b2. The predictive power of salivary Spike-IgG makes it highly suitable for screening vulnerable groups for revaccination. Knut and Alice Wallenberg Foundation, Erling Perssons family foundation, Region Stockholm, Swedish Research Council, Karolinska Institutet, Swedish Blood Cancer Foundation, PID patient organization of Sweden, Nordstjernan AB, Center for Medical Innovation (CIMED), Swedish Medical Research Council, Stockholm County Council (ALF).

Category: Biochemistry

Category: Health

Category: Vaccines

Funder: KAW/SciLifeLab

Funder: VR

Research Area: Vaccine

Type: Journal article

PubMed 35075450

DOI 10.1016/j.medj.2022.01.001

Crossref 10.1016/j.medj.2022.01.001

pii: S2666-6340(22)00036-8
pmc: PMC8770252

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