{"entity": "publication", "iuid": "2b0cde648de0418c90125278620da165", "timestamp": "2026-09-28T11:20:02.534Z", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/2b0cde648de0418c90125278620da165.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/2b0cde648de0418c90125278620da165"}}, "title": "Comparison of SARS-CoV-2 spike-specific IgA and IgG in nasal secretions, saliva and serum.", "authors": [{"family": "Bladh", "given": "Oscar", "initials": "O"}, {"family": "Aguilera", "given": "Katherina", "initials": "K"}, {"family": "Marking", "given": "Ulrika", "initials": "U"}, {"family": "Kihlgren", "given": "Martha", "initials": "M"}, {"family": "Greilert Norin", "given": "Nina", "initials": "N"}, {"family": "Smed-S\u00f6rensen", "given": "Anna", "initials": "A"}, {"family": "S\u00e4llberg Chen", "given": "Margaret", "initials": "M"}, {"family": "Klingstr\u00f6m", "given": "Jonas", "initials": "J"}, {"family": "Blom", "given": "Kim", "initials": "K"}, {"family": "Russell", "given": "Michael W", "initials": "MW"}, {"family": "Havervall", "given": "Sebastian", "initials": "S"}, {"family": "Th\u00e5lin", "given": "Charlotte", "initials": "C"}, {"family": "\u00c5berg", "given": "Mikael", "initials": "M"}], "type": "journal article", "published": "2024-03-15", "journal": {"title": "Front Immunol", "issn": "1664-3224", "volume": "15", "pages": "1346749", "issn-l": "1664-3224"}, "abstract": "Several novel vaccine platforms aim at mucosal immunity in the respiratory tract to block SARS-CoV-2 transmission. Standardized methods for mucosal sample collection and quantification of mucosal antibodies are therefore urgently needed for harmonized comparisons and interpretations across mucosal vaccine trials and real-world data.\n\nUsing commercial electrochemiluminescence antibody panels, we compared SARS-CoV-2 spike-specific IgA and IgG in paired saliva, nasal secretions, and serum from 1048 healthcare workers with and without prior infection.\n\nSpike-specific IgA correlated well in nasal secretions and saliva (r>0.65, p<0.0001), but the levels were more than three-fold higher in nasal secretions as compared to in saliva (p<0.01). Correlations between the total population of spike-specific IgA and spike-specific secretory IgA (SIgA) were significantly stronger (p<0.0001) in nasal secretions (r=0.96, p<0.0001) as opposed to in saliva (r=0.77, p<0.0001), and spike-specific IgA correlated stronger (p<0.0001) between serum and saliva (r=0.73, p<0.001) as opposed to between serum and nasal secretions (r=0.54, p<0.001), suggesting transudation of monomeric spike specific IgA from the circulation to saliva. Notably, spike-specific SIgA had a markedly higher SARS-CoV-2 variant cross-binding capacity as compared to the total population of spike specific IgA and IgG in both nasal secretions, saliva and serum, (all p<0.0001), which emphasizes the importance of taking potential serum derived monomeric IgA into consideration when investigating mucosal immune responses.\n\nTaken together, although spike-specific IgA can be reliably measured in both nasal secretions and saliva, our findings imply an advantage of higher levels and likely also a larger proportion of SIgA in nasal secretions as compared to in saliva. We further corroborate the superior variant cross-binding capacity of SIgA in mucosal secretions, highlighting the potential protective benefits of a vaccine targeting the upper respiratory tract.", "doi": "10.3389/fimmu.2024.1346749", "pmid": "38558811", "labels": [], "xrefs": [{"db": "pmc", "key": "PMC10978617"}], "notes": [], "created": "2026-09-23T08:55:11.678Z", "modified": "2026-09-23T08:55:11.716Z"}