CD4 and influenza: Supplementary Figure 1b shown the keywords with high frequency in every cluster and their connections. And, the top 10 representative keywords in each cluster were shown in Supplementary Table 1 in line with their co-occurrence frequency. The representative keywords of the #0 cluster were antibody, cell, antibody response, influenza, therapy, immunogenicity, cancer, cellular, immunity, CD4+ T cell, and safety.