Salma Sheikh-Mohamed, B. Isho, G. Chao, Michelle Zuo, G. Nahass, Rachel E. Salomon-Shulman, G. Blacker, Mahya Fazel-Zarandi, B. Rathod, K. Colwill, A. Jamal, Zhijie Li, Keelia Quinn de Launay, A. Takaoka, Julie Garnham-Takaoka, C. Fahim, Aimee Paterson, Angel Xinliu Li, Nazrana Haq, S. Barati, L. Gilbert, K. Green, M. Mozafarihashjin, Philip G. Samaan, P. Budylowski, W. Siqueira, S. Mubareka, M. Ostrowski, J. Rini, O. Rojas, A. McGeer, I. Weissman, M. Tal, S. Straus, A. Gingras, J. Gommerman
medRxiv, 2021
Vaccines against SARS-CoV-2 administered via the parenteral route (intra-muscular = i.m.) are effective at preventing COVID-19 in part by inducing neutralizing antibodies in the blood. The first line of defense against SARS-CoV-2 is in the upper respiratory tract, yet we know very little about whether COVID-19 vaccines induce immunity in this compartment, if at all. We analysed salivary antibodies against the SARS-CoV-2 Spike protein and its receptor binding domain (RBD) following 2 i.m. injections of either BNT162b2 or mRNA-1273 vaccines. Salivary anti-Spike/RBD IgG was detected after 1 dose and increased further after dose 2, reflecting the systemic immune response. Interestingly, salivary anti-Spike/RBD IgA associated with the secretory component (sIgA) was detected in nearly all vaccinated participants after one dose of mRNA vaccine, with anti-Spike sIgA diminishing after dose 2. Vaccination with ChAdOx1-S (Ad) followed by mRNA induced similar levels of salivary anti-Spike/RBD IgG and IgA, and both mRNA/mRNA and Ad/mRNA regimes provoked modest neutralizing capacity in this biofluid. Our results demonstrate that SARS-CoV-2 mRNA/mRNA and Ad/mRNA vaccination induces antibodies in the saliva, and in response to one dose of mRNA, a compartmentalized and transient antigen-specific sIgA response is generated that does not correlate with systemic immunity.
Cited by 3 publications.
Field of study: Medicine