Unified Synthesis of 2-Isocyanoallopupukeanane and 9-Isocyanopupukeanane through a "Contra-biosynthetic" Rearrangement.

Herein, we describe our synthetic efforts toward the pupukeanane natural products, in which we have completed the first enantiospecific route to 2-isocyanoallopupukeanane in 10 steps (formal synthesis), enabled by a key Pd-mediated cyclization cascade. This subsequently facilitated an unprecedented bio-inspired "contra-biosynthetic" rearrangement, providing divergent access to 9-isocyanopupukeanane in 15 steps (formal synthesis). Computational studies provide insight into the nature of this rearrangement.

Iron-Catalyzed Biomimetic Dimerization of Tryptophan-Containing Peptides.

Biomimetic oxidative dimerization of tryptophan derivatives in aqueous media with oxygen as a bulk oxidant catalyzed by an iron octacarboxy phthalocyanine complex was established. The discovery of the extremely active iron catalyst enables aerobic enzyme-mimetic oxidation to be performed in a flask. This method was applicable to the oxidative dimerization of a wide range of tryptophan derivatives, including various dipeptides and oligopeptides, with remarkable functional-group tolerance without the protection of the amino acid residues. Furthermore, oxidative dimerization of tryptophan derivatives bearing dioxopiperazine units enabled the convergent total synthesis of five natural pyrroloindole compounds and unnatural congeners. The established chemical method provides facile access to a broad range of dimerized peptides with a unique scaffold to link two turn structures, which will serve as a powerful tool to create new small- and medium-sized-molecules as drug candidates.

Type 1 inflammatory endotype relates to low compliance, lung fibrosis, and severe complications in COVID-19.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is an acute respiratory disease; approximately 5% of patients developing severe COVID-19. It is known that cytokine release is associated with disease severity, but the relationship between the different clinical phenotypes and inflammatory endotypes is not well understood. OBJECTIVE: This study investigated the association between inflammatory biomarker-based endotypes and severe COVID-19 phenotypes. METHODS: Interleukin (IL) -6, C-reactive protein (CRP), C-X-C motif chemokine (CXCL) 9, IL-18, C-C motif chemokine (CCL) 3, CCL17, IL-10, and vascular endothelial growth factor (VEGF) were measured in 57 COVID-19 patients, and their association with clinical characteristics was examined using a cluster analysis. RESULTS: Significantly higher blood levels of the eight inflammatory markers were noted in patients who developed acute respiratory distress syndrome (ARDS) than in those who did not develop ARDS (non-ARDS). Using a cluster analysis, the patient groups were classified into four clusters, of which two had patients with high IL-6 and CRP levels. In the cluster with high levels of Type 1 (T1) inflammatory markers such as CXCL9 and IL-18, 85% of the patients had ARDS, 65% of the patients developed acute kidney injury (AKI), and 78% of the patients developed pulmonary fibrosis. CONCLUSIONS: In the cluster with high levels of T1 inflammatory markers, the patients frequently suffered from tissue damage, manifested as ARDS and AKI. Our findings identified distinct T1 inflammatory endotypes of COVID-19 and suggest the importance of controlling inflammation by monitoring T1 biomarkers and treating accordingly to limit the severity of the disease.

Aerobic Dehydrogenation of N-Heterocycles with Grubbs Catalyst: Its Application to Assisted-Tandem Catalysis to Construct N-Containing Fused Heteroarenes.

An aerobic dehydrogenation of nitrogen-containing heterocycles catalyzed by Grubbs catalyst is developed. The reaction is applicable to various nitrogen-containing heterocycles. The exceptionally high functional group compatibility of this method was confirmed by the oxidation of an unprotected dihydroindolactam V to indolactam V. Furthermore, by taking advantage of the oxygen-mediated structural change of the Grubbs catalyst, we integrated ring-closing metathesis and subsequent aerobic dehydrogenation to develop the novel assisted-tandem catalysis using molecular oxygen as a chemical trigger. The utility of the assisted-tandem catalysis was demonstrated by the concise synthesis of N-containing fused heteroarenes including a natural antibiotic, pyocyanine.

Immune-complex level of cofilin-1 in sera is associated with cancer progression and poor prognosis in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies. To improve its outcome, reliable biomarkers are urgently needed. In this study, we aimed to elucidate the key molecules involved in PDAC progression using proteomics approaches. First, we undertook 2-D electrophoresis to identify the proteins overexpressed in PDAC tissues. Following the analysis of agarose gel spots, cofilin-1 was identified and verified as a candidate protein commonly upregulated in PDAC tissues. In immunohistochemistry, cofilin-1 was strongly expressed in the cytoplasm of PDAC cells. Samples were divided into two groups based on the level of cofilin-1 expression. The high expression group showed significantly higher incidence of hematogenous dissemination in relapsed patients than the low expression group (P = 0.0083). In in vitro experiments, knockdown of cofilin-1 significantly decreased chemotaxis in PDAC cell lines. After we confirmed that cofilin-1 was secreted from PDAC cells, we established a detection system for the immune-complex of cofilin-1 in sera. Using this system, we measured the IC levels of cofilin-1 in sera and observed that the IC levels of cofilin-1 in PDAC patients were higher than those in healthy volunteers and patients with pancreatitis (PDAC vs. healthy volunteers, P < 0.0001; PDAC vs. patients with pancreatitis, P < 0.026). Notably, the IC levels of cofilin-1 showed a stepwise increase during PDAC progression (P = 0.0034), and high IC levels of cofilin-1 indicated poor prognosis of patients after surgery (P = 0.039). These results suggest that the IC of cofilin-1 in sera is a potentially attractive serum biomarker for the prognosis of PDAC.

Fibrinogen alpha C chain 5.9 kDa fragment (FIC5.9), a biomarker for various pathological conditions, is produced in post-blood collection by fibrinolysis and coagulation factors.

BACKGROUND: Fibrinogen alpha C chain 5.9 kDa fragment (FIC5.9) is a new serum biomarker for chronic hepatitis that was discovered by proteomics analysis. Previous studies have shown that FIC5.9 is derived from the C-terminal region of fibrinogen alpha chain and the serum levels of FIC5.9 decrease in chronic hepatitis. It also have been reported that FIC5.9 cannot be detected in the blood stream of the systemic circulation and it is released from fibrinogen during blood clotting in collecting tube. However, the mechanism of FIC5.9 releasing from fibrinogen is unclear. METHODS: We formulated a hypothesis that FIC5.9 is released by enzymes that are activated by post-blood collection and may be coagulation and fibrinolysis factors. In this study, we analyzed the mechanisms of FIC5.9 releasing from fibrinogen in healthy blood. RESULTS: Our analysis showed that thrombin acts as an initiator for FIC5.9 releasing, and that mainly plasmin cleaves N-terminal end of FIC5.9 and neutrophil elastase cleave C-terminal end of FIC5.9. CONCLUSION: FIC5.9 reflects minute changes in coagulation and fibrinolysis factors and may be associated with pathological conditions.

Synthesis of the Core Tricyclic Ring Domain of (-)-Schulzeine B.

A formal synthesis of (-)-schulzeine B, a marine natural alkaloid possessing potent antidiabetic activity, has been achieved. A benzo[a]quinolizidin-4-one is a common skeleton of schulzeines (A-C). (-)-Schulzeine B possesses an (S)-stereogenic center at the C-3 carbon. The chiral (3S,11bS)-3-amino-9,11-dimethoxybenzo[a]quinolizidin-4-one has been prepared efficiently from (2-bromo-3,5-dihydroxyphenyl)acetonitrile in 17 steps including (i) a dehydrative intramolecular amination catalyzed by HClO4 and (ii) a proline or boric acid catalyzed transcycloamidation reaction for the construction of the δ-lactam ring.

Cost-effectiveness comparison between blood biomarkers and conventional tests in Alzheimer's disease diagnosis.

Dementia management has evolved with drugs such as lecanemab, shifting management from palliative care to early diagnosis and intervention. However, the administration of these drugs presents challenges owing to the invasiveness, high cost and limited availability of amyloid-PET and cerebrospinal fluid tests for guiding drug administration. Our manuscript explores the potential of less invasive blood biomarkers as a diagnostic method, with a cost-effectiveness analysis and a comparison with traditional tests. Our findings suggest that blood biomarkers are a cost-effective alternative, but with lower accuracy, indicating the need for multiple specific biomarkers for precision. This underscores the importance of future research on new blood biomarkers and their clinical efficacy.

Global biomarker trends in Alzheimer's research: A bibliometric analysis.

Alzheimer's disease (AD) has no effective treatment, although antibody drugs targeting beta-amyloid, mainly aducanumab, have produced useful clinical results. Biomarkers can be used to determine drug regimens effectively and to monitor the effects of drugs. A concept in which biomarkers reflect disease states is emerging. Although several AD biomarker studies have been reported, measurement methods and target molecules are still being validated, and various biomarkers are being explored. This study analyzed trends in research on AD biomarkers using bibliometric methods, revealing an exponential increase in research reports in this field, with the US most active in research. Analysis of the 'Burst' biomarkers using CiteSpace revealed that networks centered on authors, rather than networks among countries, drive new research trends in this area.

Soluble programmed cell death ligand 1 predicts prognosis for gastric cancer patients treated with nivolumab: Blood-based biomarker analysis for the DELIVER trial.

BACKGROUND: The clinical value of soluble forms of programmed cell death-1 (sPD-1), PD ligand 1 (sPD-L1) and cytotoxic T lymphocyte-associated protein-4 (sCTLA-4) for gastric cancer (GC) patients treated with nivolumab monotherapy has remained unknown. METHODS: Blood samples collected before nivolumab treatment from 439 GC patients enrolled in the DELIVER (Japan Clinical Cancer Research Organisation GC-08) trial were analysed for sPD-1, sPD-L1 and sCTLA-4. Corresponding baseline clinical data were also retrieved. RESULTS: Higher plasma levels of sPD-1 (hazard ratio [HR] = 1.27, p = 0.020), sPD-L1 (HR = 1.86, p < 0.001) and sCTLA-4 (HR = 1.33, p = 0.008) were significantly associated with shorter overall survival (OS), whereas only higher sPD-L1 levels was significantly associated with shorter progression-free survival (HR = 1.30, p = 0.008). The sPD-L1 concentration was significantly associated with the Glasgow prognostic score (GPS) (p < 0.001), but both sPD-L1 (HR = 1.67, p < 0.001) and GPS (HR = 1.39, p = 0.009 for GPS 0 versus 1; HR = 1.95, p < 0.001 for GPS 0 versus 2) were independently associated with OS. Patients with a GPS of 0 and low sPD-L1 thus showed the longest OS (median, 12.0 months) and those with a GPS of 2 and high sPD-L1 showed the shortest OS (median, 3.1 months), yielding a HR of 3.69 (p < 0.001). CONCLUSION: Baseline sPD-L1 levels have the potential to predict survival for advanced GC patients treated with nivolumab, with the prognostic accuracy of sPD-L1 being improved by its combination with GPS.

Lack of Association of Plasma Levels of Soluble Programmed Cell Death Protein 1, Programmed Death-Ligand 1, and CTLA-4 With Survival for Stage II to IIIA NSCLC After Complete Resection and Adjuvant Chemotherapy.

Introduction: Perioperative treatment in NSCLC has gained marked attention with the introduction of immune checkpoint inhibitors. Such a paradigm shift has given us additional opportunities to evaluate potential biomarkers in patients with these curable disease stages. Methods: This study (WJOG12319LTR) was designed as a biomarker study to evaluate whether soluble immune markers were prognostic or predictive on relapse-free survival in patients with stage II to IIIA NSCLC who underwent complete resection and adjuvant chemotherapy with cisplatin plus S-1, which is an oral fluoropyrimidine formulation that consists of tegafur, gimeracil, and oteracil, or S-1 alone in the previous WJOG4107 study. Archived plasma samples were assayed for soluble (s) forms of programmed cell death protein 1 (sPD-1), programmed death-ligand 1(sPD-L1), and CTLA-4 (sCTLA-4) with the highly sensitive HISCL system. Using time-dependent receiver operating characteristic curve analysis, the area under the curves were derived and optimal cutoff values were determined. Using the cutoff values, whether the marker was prognostic or predictive was assessed by survival analysis. Results: A total of 150 patients were included in the study. The time-dependent receiver operating characteristics analysis revealed that the area under the curves for sPD-1, sPD-L1, and sCTLA-4 were 0.54, 0.51, and 0.58, respectively. The survival analysis did not reject that hazard ratios were 1 in terms of the soluble immune marker and the treatment-marker interaction for all three markers. Conclusions: There was no proof that circulating concentrations of sPD-1, sPD-L1, and sCTLA-4 were prognostic or predictive factors of the outcome for adjuvant chemotherapy after complete resection in patients with NSCLC.

Serum anti-Ku86 is a potential biomarker for early detection of hepatitis C virus-related hepatocellular carcinoma.

Hepatocellular carcinoma (HCC), the predominant form of primary liver cancer, is one of the most common cancers worldwide and the third most common cause of cancer-related death. Imaging studies including ultrasound and computed tomography are recommended for early detection of HCC, but they are operator dependent, costly and involve radiation. Therefore, there is a need for simple and sensitive serum markers for the early detection of hepatocellular carcinoma (HCC). In our recent proteomic studies, a number of proteins overexpressed in HCC tissues were identified. We thought if the serum autoantibodies to these overexpressed proteins were detectable in HCC patients. Of these proteins, we focused on Ku86, a nuclear protein involved in multiple biological processes and aimed to assess the diagnostic value of serum anti-Ku86 in the early detection of HCC. Serum samples were obtained prior to treatment from 58 consecutive patients with early or relatively early hepatitis C virus (HCV)-related HCC and 137 patients with HCV-related liver cirrhosis without evidence of HCC. Enzyme immunoassays were used to measure serum levels of autoantibodies. Serum levels of anti-Ku86 antibodies were significantly elevated in HCC patients compared to those in liver cirrhosis patients (0.41±0.28 vs. 0.18±0.08Abs at 450nm, P<0001). Setting the cut-off level to give 90% specificity, anti-Ku86 was positive in 60.7% of stage I solitary tumor <2cm in diameter, whereas the sensitivities of alpha-fetoprotein (AFP) and protein induced by vitamin K absence or antagonist II (PIVKA-II) were 17.8% and 21.4%, respectively. The results of ROC analyses indicated the better performance of anti-Ku86 for early detection of HCC. Serum anti-Ku86 levels decreased after surgical resection of the tumors in the 12 HCC cases tested, Elevation of anti-Ku86 in solid tumors other than liver was minimal. Serum anti-Ku86 is a potential biomarker for early detection of HCV-related HCC. Further studies in a larger number of HCC patients with various etiologies are needed to further evaluate the diagnostic and pathophysiological roles of elevation of serum anti-Ku86 in early HCC.

Th1 cytokine endotype discriminates and predicts severe complications in COVID-19

Treatment of severe and critical cases of coronavirus disease 2019 (COVID-19) is still a top priority in public health. Previously, we reported distinct Th1 cytokines related to the pathophysiology of severe COVID-19 condition. In the present study, we investigated the association of Th1 and Th2 cytokine/chemokine endotypes with cell-mediated immunity via multiplex immunophenotyping, single-cell RNA-Seq analysis of peripheral blood mononuclear cells, and analysis of the clinical features of COVID-19 patients. Based on serum cytokine and systemic inflammatory markers, COVID-19 cases were classified into four clusters of increasing (I-IV) severity. Two prominent clusters were of interest and could be used as prognostic reference for a targeted treatment of severe COVID-19 cases. Cluster III reflected severe/critical pathology and was characterized by decreased in CCL17 levels and increase in IL-6, C-reactive protein CXCL9, IL-18, and IL-10 levels. The second cluster (Cluster II) showed mild to moderate pathology and was characterized by predominated CXCL9 and IL-18 levels, levels of IL-6 and CRP were relatively low. Cluster II patients received anti-inflammatory treatment in early-stage, which may have led prevent disease prognosis which is accompanied to IL-6 and CRP induction. In Cluster III, a decrease in the proportion of effector T cells with signs of T cell exhaustion was observed. This study highlights the mechanisms of endotype clustering based on specific inflammatory markers in related the clinical outcome of COVID-19.

Synthesis of α-substituted indolylacetamide using acetonitriles as acetamide enolate equivalents through O-transfer reactions.

We introduce readily available ammonium hemiaminals as O-transfer reagents and commercially available acetonitriles as a primary amide enolate precursor. The combination serves as an amide enolate equivalent, thereby providing one-pot access to α-substituted indolylacetamides. A broad substrate scope and good functional group tolerance as well as gram-scale synthesis make this protocol highly attractive. Mechanistic experiments suggest that the cyano group is trapped by a hydroxy group of hemiaminals en route to the desired primary amides under metal-free conditions.

Role of enteric dopaminergic neurons in regulating peristalsis of rat proximal colon.

BACKGROUND: Constipation is commonly seen in patients with Parkinson's disease associated with a loss of dopaminergic neurons in both central and enteric nervous systems. However, the roles of enteric dopaminergic neurons in developing constipation remain to be elucidated. Here, we investigated the roles of enteric dopaminergic neurons in the generation of colonic peristalsis. METHODS: Cannulated segments of rat proximal colon were situated in the organ bath, abluminally perfused with physiological salt solution and luminally perfused with 0.9% saline. Drugs were applied in the abluminal solution. Changes in diameter along the length of the colonic segment were captured by a video camera and transformed into spatio-temporal maps. Fluorescence immunohistochemistry was also carried out. KEY RESULTS: Blockade of nitrergic neurotransmission prevented oro-aboral propagation of peristaltic waves and caused a colonic constriction without affecting ripples, non-propagating myogenic contractions. Blockade of cholinergic neurotransmission also prevented peristaltic waves but suppressed ripples with a colonic dilatation. Tetrodotoxin (0.6 µM) abolished peristaltic waves and increased ripples with a constriction. SCH 23390 (20 µM), a D1 -like dopamine receptor antagonist, slowed the peristaltic waves and caused a constriction, while GBR 12909 (1 µM), a dopamine reuptake inhibitor, diminished the peristaltic waves with a dilatation. Bath-applied dopamine (3 µM) abolished the peristaltic waves associated with a colonic dilation in an SCH 23390 (5 µM)-sensitive manner. D1 receptor immunoreactivity was co-localized to nitrergic and cholinergic neurons. CONCLUSIONS AND INFERENCES: Dopaminergic neurons appear to facilitate nitrergic neurons via D1 -like receptors to stabilize asynchronous contractile activity resulting in the generation of colonic peristalsis.

Quantification of Amyloid-ß in Plasma by Simple and Highly Sensitive Immunoaffinity Enrichment and LC-MS/MS Assay.

BACKGROUND: Numerous immunoassays have been developed to quantify amyloid ß1-40 (Aß40) and amyloid ß1-42 (Aß42). Nevertheless, given the low concentration of Aß and the high levels of interfering factors in plasma, quantification of plasma Aß is still challenging. To overcome the problems related to the specificity of Aß immunoassays, this study aimed to develop an immunoaffinity enrichment and LC-MS/MS (IA-MS) assay. METHODS: We developed an IA-MS assay using antibody-labeled magnetic beads for purification and LC-MS/MS for Aß quantification. To avoid the loss of Aß due to aggregation in acidic buffer, we used alkaline elution buffer for immunoaffinity enrichment. The concentrations of the Aßs in plasma samples were measured, and the correlation between the plasma and cerebrospinal fluid (CSF) Aß42/Aß40 ratio was also evaluated. RESULTS: The intensities of the Aß mass peaks were significantly higher with the alkaline elution buffer than with the acidic elution buffer (Aß40: 3.6-fold, Aß42: 5.4-fold). This assay exhibited high reproducibility (intra-assay and inter-assay precision, %CV <15), and the working ranges of Aß40 and Aß42 were determined to be 21.7 to 692.8 pg/mL and 5.6 to 180.6 pg/mL, respectively. The concentrations of Aß40 and Aß42 in plasma were measured by IA-MS, and the plasma Aß42/Aß40 ratio was correlated with the CSF Aß42/Aß40 ratio (rs = 0.439, P < 0.01). CONCLUSIONS: The IA-MS assay has sufficient analytic performance for measuring endogenous Aß40 and Aß42 in plasma. This assay can lead to new lines of clinical discovery related to amyloid pathology.

A novel highly quantitative and reproducible assay for the detection of anti-SARS-CoV-2 IgG and IgM antibodies.

The quantitative range and reproducibility of current serological tests for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) are not optimized. Herein, we developed a diagnostic test that detects SARS-CoV-2 IgG and IgM with high quantitativeness and reproducibility and low interference. The system was based on the high-sensitivity chemiluminescence enzyme immunoassay (HISCL) platform and detects IgG and IgM specific to SARS-CoV-2 spike and nucleocapsid proteins. Quantification accuracy and reproducibility were evaluated using serially diluted samples from 60 SARS-CoV-2-infected patients. Assay performance was evaluated using serum samples from the SARS-CoV-2-infected patients and 500 SARS-CoV-2-negative serum samples collected before the emergence of SARS-CoV-2. The system showed high quantification accuracy (range, 102), high reproducibility (within 5%), and no cross-reaction between SARS1- and MERS-S proteins. Detection accuracy was 98.3% and 93.3% for IgG and IgM against spike proteins and 100% and 71.7% for IgG and IgM against nucleocapsid proteins, respectively. Mean antibody levels were > 10 times that in negative samples upon admission and > 100 times that at convalescent periods. Clinical severity upon admission was not correlated with IgG or IgM levels. This highly quantitative, reproducible assay system with high clinical performance may help analyze temporal serological/immunological profiles of SARS-CoV-2 infection and SARS-CoV-2 vaccine effectiveness.

A novel automated immunoassay for serum NY-ESO-1 and XAGE1 antibodies in combinatory prediction of response to anti-programmed cell death-1 therapy in non-small-cell lung cancer.

BACKGROUND: Anti-programmed cell death-1 (PD-1) antibodies (Abs) are key drugs in non-small-cell lung cancer (NSCLC) treatment; however, clinical benefits with anti-PD-1 monotherapy are limited. We reported that serum Abs against cancer-testis antigens NY-ESO-1 and XAGE1 predicted clinical benefits. We aimed to develop a fully automated immunoassay system measuring NY-ESO-1/XAGE1 Abs. METHODS: Sera from 30 NSCLC patients before anti-PD-1 monotherapy were reacted with recombinant NY-ESO-1 protein- or synthetic XAGE1 peptide-coated magnetic beads. ALP-conjugated Ab and chemiluminescent substrate were added and luminescence measured. These procedures were automated using high sensitivity chemiluminescent enzyme immunoassay (HISCL™). NY-ESO-1/XAGE1 Ab stability was tested under various conditions. Response prediction accuracy was evaluated using area under receiver operating curve (AUROC). RESULTS: HISCL detected specific serum NY-ESO-1/XAGE1 Abs, which levels in ELISA and HISCL were highly correlated. The Ab levels in HISCL were stable at four temperatures, five freeze/thaw cycles, and long-term storage; the levels were not interfered by common blood components. The Ab levels in 15 NSCLC responders to anti-PD-1 monotherapy were significantly higher than those in non-responders and healthy donors. The AUROC was the highest (0.91; 95% CI, 0.78-1.0) in combinatory prediction with NY-ESO-1/XAGE1 Abs. CONCLUSION: Our immunoassay system is useful to predict clinical benefits with NSCLC immune-checkpoint therapy.

Correlates of neutralizing/SARS-CoV-2-S1-binding antibody response with adverse effects and immune kinetics in BNT162b2-vaccinated individuals.

While mRNA vaccines against SARS-CoV-2 are exceedingly effective in preventing symptomatic infection, their immune response features remain to be clarified. In the present prospective study, 225 healthy individuals in Japan, who received two BNT162b2 doses, were enrolled. Correlates of BNT162b2-elicited SARS-CoV-2-neutralizing activity (50% neutralization titer: NT50; assessed using infectious virions) with various determinants were examined and the potency of sera against variants of concerns was determined. Significant rise in NT50s was seen in sera on day 28 post-1st dose. A moderate inverse correlation was seen between NT50s and ages, but no correlation seen between NT50s and adverse effects. NT50s and SARS-CoV-2-S1-binding-IgG levels on day 28 post-1st dose and pain scores following the 2nd dose were greater in women than in men. The average half-life of NT50s was ~ 68 days, and 23.6% (49 out of 208 individuals) failed to show detectable neutralizing activity on day 150. While sera from elite-responders (NT50s > 1,500: the top 4% among the participants) potently to moderately blocked all variants of concerns examined, some sera with low NT50s failed to block the B.1.351-beta strain. Since BNT162b2-elicited immunity against SARS-CoV-2 is short, an additional vaccine or other protective measures are needed.

Correlates of Neutralizing/SARS-CoV-2-S1-binding Antibody Response with Adverse Effects and Immune Kinetics in BNT162b2-Vaccinated Individuals.

BACKGROUND: While mRNA vaccines against SARS-CoV-2 have been exceedingly effective in preventing symptomatic viral infection, the features of immune response remain to be clarified. METHODS: In the present prospective observational study, 225 healthy individuals in Kumamoto General Hospital, Japan, who received two BNT162b2 doses in February 2021, were enrolled. Correlates of BNT162b2-elicited SARS-CoV-2-neutralizing activity (50% neutralization titer: NT 50 ; assessed using infectious virions and live target cells) with SARS-CoV-2-S1-binding-IgG and -IgM levels, adverse effects (AEs), ages, and genders were examined. The average half-life of neutralizing activity and the average time length for the loss of detectable neutralizing activity were determined and the potency of serums against variants of concerns was also determined. FINDINGS: Significant rise in NT 50 s was seen in serums on day 28 post-1st dose. A moderate inverse correlation was seen between NT 50 s and ages, but no correlation was seen between NT 50 s and AEs. NT 50 s and IgG levels on day 28 post-1st dose and pain scores following the 2nd shot were greater in women than in men. The average half-life of neutralizing activity in the vaccinees was approximately 67.8 days and the average time length for their serums to lose the detectable neutralizing activity was 198.3 days. While serums from elite-responders (NT 50 s>1,500-fold: the top 4% among all participants' NT 50 s) potently to moderately blocked the infectivity of variants of concerns, some serums with moderate NT 50 s failed to block the infectivity of a beta strain. INTERPRETATION: BNT162b2-elicited immune response has no significant association with AEs. BNT162b2-efficacy is likely diminished to under detection limit by 6-7 months post-1st shot. High-level neutralizing antibody-containing serums potently to moderately block the infection of SARS-CoV-2 variants; however, a few moderate-level neutralizing antibody-containing serums failed to do so. If BNT162b2-elicited immunity memory is short, an additional vaccine or other protective measures would be needed. RESEARCH IN CONTEXT: Evidence before this study: While mRNA vaccines against SARS-CoV-2 have been exceedingly effective in preventing symptomatic viral infection, the salient features of immune response including the persistence of protection remain to be clarified. There is a report that anti-SARS-CoV-2 antibodies persist through 6 months after the second dose of mRNA-1273 vaccine (Doria-Rose et al. N Engl J Med . 2021;384:2259-2261); however, more definite immune kinetics following mRNA-vaccine-elicited protection have to be clarified. The mRNA-vaccine-elicited protection against SARS-CoV-2 variants are also to be determined. Added value of this study: In the present prospective study, 225 twice-BNT162b2-dose-receiving individuals in Japan were enrolled. No significant correlation was seen between 50% neutralizing titers (NT 50 s), determined by using infectious SARS-CoV-2 virions and live target cells, and adverse effects. Largely, NT 50 s and IgG levels were greater in women than in men. Following 28 days post-2 nd shot, significant reduction was seen in NT 50 s, IgG, and IgM levels. The average half-life of NT 50 s was ∼68 days and the average time-length for participants' serums to lose the detectable activity was ∼198 days. Although serums from elite-responders potently to moderately blocked the infectivity of variants of concerns, some serums with moderate NT 50 s failed to block the infectivity of a beta strain. Implications of all the available evidence: BNT162b2 efficacy is likely to be diminished to under detection limit by 6-7 months post-1 st shot on average. Individuals with moderate NT 50 s may fail to block beta variants. If BNT162b2-elicited immune memory is lost soon, additional vaccine(s) or other protective means would be needed.