PMC8342944_01
Time course of SARS-CoV-2 vaccinations, antibody response, and infection in our subject. The green line shows the course of SARS-CoV-2 spike-specific antibodies in the patient. A first rapid antigen test was positive 49 days after the second vaccination, a first positive RT-PCR 2 days later. Note that 250 U/ml were the upper threshold value of the ELISA, the result for both data points in this assay was above the limit of accurate detection (>250 U/ml). The blue line shows the SARS-CoV-2 RT-PCR cycle threshold (Ct) value of the laryngopharyngeal swab samples taken from the patient on 5 different days around the time point of infection (results shown here for E gene Ct's). Note that the first positive RT-PCR showed the lowest viral load (highest Ct) of all three positive tests. The Roche Elecsys  N-specifc ELISAs performed on days 5, 10, and 20 days after first positive SARS-CoV-2 antigen test were negative at COIs 0.065, 0.46, and 0.569, respectively (threshold for positive result: 1.0), see also Supplementary Figure 1.
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F1
Forty-nine days after receiving his second dose of SARS-CoV-2 mRNA vaccine BNT162b2 a 42-year old, otherwise healthy male tested positive for SARS-CoV-2 in a rapid antigen test, which was confirmed in a laryngopharyngeal swab by RT-PCR for two viral targets (E and S genes as previously described), two days later (see Figure 1). Maximum levels were reached 9 days after the second vaccination (Figure 1). Surprisingly, in these neutralizing samples no nucleocapsid (N)-specific antibodies could be detected up to 20 days after infection (Figure 1, Roche Elecsys  Anti-SARS-CoV-2 immunoassay and Supplementary Figure 1), while spike (S)-specific antibodies stayed at the highest detectable levels or above (Euroimmun SARS-CoV-2 ELISA).
Plaque count after neutralisation assay with serial dilutions of the patient's serum on SARS-CoV-2 variants B.3, B.1.1.7, B.1.351, and B.1.525. The capacity of the serum to neutralise the different variants was correlated to the prevention of plaque formation. The plasma sample was diluted between a range of 1:4 (50 mul in 200 mul, see x axis) and 1:2048 to assess its titer for neutralisation. Results of four independent experiments are shown. Variations in NT values between experiments are indicated by an error bar.
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F2
SARS-CoV-2 variants B.3, B.1.117 (alpha variant), B.1.351 (beta), and B.1.525 (eta). Surprisingly, the plasma was equally capable of neutralizing B.1.525 virus as the other variants with slightly lower NT activity against B.1.351 (see Figure 2). Surprisingly, in these neutralizing samples no nucleocapsid (N)-specific antibodies could be detected up to 20 days after infection (Figure 1, Roche Elecsys  Anti-SARS-CoV-2 immunoassay and Supplementary Figure 1), while spike (S)-specific antibodies stayed at the highest detectable levels or above (Euroimmun SARS-CoV-2 ELISA).
Neutralisation capacity of patient's plasma on days 5, 10, and 13 after first positive SARS-CoV-2 result. Neutralisation assays were performed with the four virus variants B.3, B.1.1.7, B.1.351, and B.1.525, the latter of which the patient had been infected with. The NT90 value is the corresponding reciprocal of the dilution at which 90% of plaques were suppressed. Results of three independent experiments are shown. Variations in NT values between experiments are indicated by an error bar.
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F3
Overall we observed a general trend for an increase in neutralization between day 5 and 13 after SARS-CoV-2 breakthrough infection (Figure 3).