The present invention represents the first systems biology approach to investigate the volunteers' immune predisposition to respond to a vaccination (proteins trimer GP160 SOSIP), assessed by their blood transcriptome profile; specifically, that related to their B cell differentiation stages. That is, inventors investigated the host gene expression in blood by a microarray approach before vaccination. The objective was to examine their potential involvement in an effective SOSIP neutralizing antibody (Nabs) response during a randomized phase lb clinical study. This trial immunized 6 HIV seronegative subjects by the intramuscular route with SOSIP -HIV clade B vaccine. Inventors found that gene expression of a group of genes (detected through mRNA nucleic acids in blood) are overexpressed at baseline in subjects with the highest antibody response compared to the subjects with the lowest antibody response, and therefore may be considered as good biomarkers to assess the humoral immune response of a subject to a vaccine. Accordingly, the present invention relates to methods and kits for predicting the humoral response of a subject prior to vaccination. More specifically present invention relates to methods for assessing the humoral response of a subject to a vaccine through detection in a blood sample of specific RNAs.