The vaccines designed against the SARS-CoV-2 coronavirus are based on the spike (S) protein. Processing of the S protein by antigen-presenting cells (APC) and its subsequent presentation to T cells is an essential part of the development of a humoral response. HLA-class II alleles are considered immune response genes because their codified molecules, expressed on the surface of APCs (macrophages, dendritic, and B cells) present antigenic peptides to T cell via their T cell receptor (TCR). The HLA-class II genes are highly polymorphic, regulating what specific peptides induce follicular helper T cells (TFH) and promote B lymphocyte differentiation into plasma or memory B cells. This work hypothesizes that the presence of certain HLA-class II alleles could be associated with the intensity of the humoral response (amount, length) to the SARS-CoV2 mRNA 1273 vaccine. We have studied the relationship between the HLA-class II typing of 87 health workers and the level of antibodies produced 30 days after vaccination. We show a possible association between the HLA-DRB1* 07:01 allele and the HLA-DRB1*07:01~DQA1*02:01~DQB1*02:02 haplotype to a higher production of antibodies 30 days after the administration of the second dose of mRNA-1273.

In August 2020, anew West Nile virus (WNV) outbreak affected 71 people with meningoencephalitis in Andalusia (Spain). Samples from these individuals were received in our laboratory, a regional Virus Referral Centre. The aim of this study was to compare the agreement, sensitivity and specificity of findings between the WNV VIRCLIA IgG and IgM assay (Vircell, Spain) and the WNV ELISA IgM and IgG assay (Euroimmun, Germany) and to compare the performance of WNV VIRCLIA IgM and Euroimmun ELISA for cerebrospinal fluid (CSF) diagnosis. The study included 24 CSF samples (paired with serum samples) and 247 serum samples from 217 patients with suspected WNV infection (1 or 2 per patient). The agreement between ELISA and CLIA tests for IgM and Ig G detection in serum was 93% (kappa index = 0.85) and 96% (kappa index = 0.89) respectively. Sensitivity values of ELISA and CLIA tests for IgM in serum samples were 96.7% and 98.9%, respectively, and specificity values were 96.4% and 95.4% respectively. Sensitivity values of ELISA and CLIA test for IgG in serum samples were 91.1% and 97%, respectively, and specificity values were 100% and 98.8% respectively. Results obtained with ELISA and CLIA tests in CSF samples showed 75% agreement between them (kappa index = 0.51). According to these findings, the WNV VIRCLIA IgM and IgG monotest offers an accurate qualitative detection of WNV in serum and CSF specimens.