Breakthrough SARS-CoV-2 infection

1. anti-SARS-CoV-2 antibody titer is associated with breakthrough SARS-CoV-2 infection in humans (HR 34.25).

   “Despite ≥ 3 vaccine doses, individuals with titers ≤ 2500 IU/mL had increased risk (HR: 34.25, p = 0.0155).”

   HumansAntibody titers ≤ 2500 IU/mL despite ≥ 3 vaccine dosesserum≥ 3 vaccine doses

   PhenoAge acceleration predicts antibody persistence and breakthrough infection after SARS-CoV-2 vaccination and infection

   Journal of infection and public health·10 Oct 2025

2. anti-SARS-CoV-2 antibody titer lowers the risk of breakthrough SARS-CoV-2 infection in humans (HR 0.04).

   “Antibody titers > 2500 IU/mL protected against breakthrough infection (HR: 0.04, p = 0.0368).”

   HumansAntibody titers > 2500 IU/mLserum

   PhenoAge acceleration predicts antibody persistence and breakthrough infection after SARS-CoV-2 vaccination and infection

   Journal of infection and public health·10 Oct 2025

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