Fig. 2: Heterologous vaccination induces higher neutralizing antibody titres.
From: Immunogenicity and efficacy of heterologous ChAdOx1–BNT162b2 vaccination
a–c, Sera from ChAd–BNT (n = 29) or BNT–BNT (n = 31) individuals were assayed for S1-specific IgG (a), RBD-specific IgG (b) or S1-specific IgA (c) levels using commercial or custom-made ELISA tests at different times during the vaccination process as indicated (a, b) or 4 weeks after full vaccination (c). In a–c, concentrations are expressed in binding antibody units per ml (BAU ml–1) or ng ml–1 Eq of immunoglobulin as indicated. Each serum sample was evaluated as a single measurement (a, b) or in triplicate (c). Dotted lines in a and b indicate positive detection according to the manufacturer. d–f, Sera from ChAd–BNT (n = 29) or BNT–BNT (n = 31) vaccinated individuals were assayed in triplicate for their capacity to neutralize the entry of virus-like particles pseudotyped with the Wuhan strain SARS-CoV-2 envelope (d) or in duplicate for their capacity to neutralize infection of Vero E6 cells by different SARS-CoV-2 strains (e, f), as indicated. Data show the per cent of neutralization relative to a positive control (d) or the 50% plaque reduction neutralization test (PRNT50) (e), and are expressed as dot plots, with one dot corresponding to one individual. The limit of detection is shown as a dotted line in e. FC, fold change in the mean of the indicated groups. In all panels, box-and-whiskers plots are shown (see Methods for details), and the median is represented by the magenta middle line. A linear regression model was used to compare values between groups, and this model was corrected for age. Exact P values are shown for the indicated comparisons when significant or nearly significant. f, Comparison of serum neutralizing activity against the reference lineage 19A and against the variants of concern for each group. P values are shown and calculated using the linear regression model described in e.
