In the in vitro assays of the pseudovirus-based ADE of infection, even luminescence as low as 1×104 (1/10 of that in the pseudovirus-based neutralization assay in Figure 3A, and background values around those detected in the VC control groups for each of the four cells) was taken as the cutoff value, and serum from neither the nucleic acid-adjuvanted S1 subunit vaccine group nor the alum-adjuvanted S1 subunit vaccine group showed ADE of infection in any of the four tested cell lines (Figures 3B–E). The gene discussed is PSMD1; the disease is infection.