For both IgG and IgA responses, a significantly broader epitope coverage was observed at Visit 5—prior to re-exposure—in individuals who did not become re-infected during the second wave (Figure 2A: p-value = 0.0187, Figure 2B: p-value = 0.0151); thus, epitope utilisation appears to correlate with protection from re-infection. The gene discussed is CD79A; the disease is infection.