Immunological findings in a group of individuals who were non-responders to standard two-dose SARS-CoV-2 vaccines

Coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was declared a pandemic. The virus has infected more than 505 million people and caused more than 6 million deaths. However, data on non-responders to SARS-CoV-2 vaccines in the general population are limited. The objective of the study is to comprehensively compare the immunological characteristics of non-responders to SARS-CoV-2 vaccines in the 18-59 years with that in the 60 years and older using internationally recognized cutoff values. Participants included 627 individuals who received physical examinations and volunteered to participate in COVID-19 vaccination from the general population. The main outcome was an effective seroconversion characterized by anti-SARS-CoV-2 spike IgG level of at least 4-fold increase from baseline. Profiling of naive immune cells was analyzed prior to vaccination to demonstrate baseline immunity. Outcomes of effective seroconversion in the 18-59 years with that in the 60 years and older were compared. The quantitative level of the anti-spike IgG was significantly lower in the 60 years and older and in men among the 18-59 years. There were 7.5% of non-responders among the 18-59 years and 11.7% of non-responders in the 60 years and older using the 4-fold increase parameter. The effective seroconversion rate was significantly related to the level of certain immune cells before vaccination, such as CD4 cells, CD8 cells and B cells and the age. An individual with a titer of anti-SARS-CoV-2 spike IgG that is below 50 BAU/mL might be considered a non-responder between 14-90 days after the last vaccine dose. Booster vaccination or additional protective measures should be recommended for non-responders as soon as possible to reduce disease severity and mortality.

Interpretation of non-responders to SARS-CoV-2 vaccines using WHO International Standard

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic with more than 485 millions infected. Questions about non-responders to SARS-CoV-2 vaccines remain unaddressed. Here, we report data from people after administering the complete dose of SARS-CoV-2 vaccines using the World Health Organization International Standard for anti-SARS-CoV-2 immunoglobulin. Our study showed that immune cells such as CD4 cells, CD8 cells, and B cells and anti-spike immunoglobulin G levels were significantly reduced in the elderly. There were 7.5% non-responders among the 18-59 yr group and 11.7% in the [≥]60 yr group. A titer of anti-SARS-CoV-2 spike immunoglobulin G is blew 50 BAU/mL to be considered as non-responders at intervals of 30 to 90 days after the last vaccine dose. Booster vaccination may be recommended for non-responders to reduce the disease severity and mortality.

Expression,Purification and Antibody Preparation of Recombinant C8orf32 Protein / 中国生物工程杂志

C8orf32 is a gene which has not been functionally characterized,the mRNA level of this gene is significantly higher in breast cancer tissues than that in normal breast tissues.The amplified cDNA fragment was inserted into the pGEX-6P1 vector fused with the upstream GST gene.The expression vector was transformed into the E.coli BL21(DE3) strain and expression of GST-C8orf32 fusion protein was induced by IPTG..After removal of GST tag by site-specific protease,the C8orf32 protein fused with an eight amino acid peptide tag was obtained.The purity of recombinant C8orf32 protein was about 95%.The identity of the purified protein was confirmed by N-terminal sequencing and tandem mass spectrometry.The polyclonal antibody was prepared by immunizing the New Zealand white rabbits with C8orf32 protein.The polyclonal antibody was proved to recognize the C8orf32 protein correctly.The purified C8orf32 protein can be used for structural and functional studies and the polyclonal antibody can be used for tissue specific protein expression profiling.