Influenza-A mediated pre-existing immunity levels to SARS-CoV-2 could predict early COVID-19 outbreak dynamics.
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Almazán NM, Rahbar A, Carlsson M, Hoffman T, Kolstad L, Rönnberg B, Pantalone MR, Fuchs IL, Nauclér A, Ohlin M, Sacharczuk M, Religa P, Amér S, Molnár C, Lundkvist Å, Susrud A, Sörensen B, Söderberg-Nauclér C
iScience 26 (12) 108441 [2023-12-15; online 2023-11-14]
Susceptibility to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections is highly variable and could be mediated by a cross-protective pre-immunity. We identified 14 cross-reactive peptides between SARS-CoV-2 and influenza A H1N1, H3N2, and human herpesvirus (HHV)-6A/B with potential relevance. The H1N1 peptide NGVEGF was identical to a peptide in the most critical receptor binding motif in SARS-CoV-2 spike protein that interacts with the angiotensin converting enzyme 2 receptor. About 62%-73% of COVID-19-negative blood donors in Stockholm had antibodies to this peptide in the early pre-vaccination phase of the pandemic. Seasonal flu vaccination enhanced neutralizing capacity to SARS-CoV-2 and T cell immunity to this peptide. Mathematical modeling taking the estimated pre-immunity levels to flu into account could fully predict pre-Omicron SARS-CoV-2 outbreaks in Stockholm and India. This cross-immunity provides mechanistic explanations to the epidemiological observation that influenza vaccination protected people against early SARS-CoV-2 infections and implies that flu-mediated cross-protective immunity significantly dampened the first SARS-CoV-2 outbreaks.
Funder: KAW/SciLifeLab National COVID program
PubMed 38144451
DOI 10.1016/j.isci.2023.108441
Crossref 10.1016/j.isci.2023.108441
pmc: PMC10746369
pii: S2589-0042(23)02518-X