Delta Infection After Vaccination Elicits Potent Neutralizing Immunity Against Severe Acute Respiratory Syndrome Coronavirus 2 Omicron.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron (B.1.1.529) variant extensively escape neutralizing antibodies by vaccines or infection. We assessed serum neutralizing activity in sera from Delta infection after vaccination and Delta infection only against SARS-CoV-2 Wuhan-Hu-1 (WA1), Beta, Delta, and Omicron. Sera from Delta infection only could neutralize WA1 and Delta but almost completely lost capacity to neutralize Beta and Omicron. However, Delta infection after vaccination resulted in a significant increase of serum neutralizing activity against WA1, Beta, and Omicron. This study demonstrates that breakthrough infection of Delta substantially induced high potency humoral immune response against the Omicron variant and other emerged variants.

Antibody and T-cellular response to COVID-19 booster vaccine in SARS-CoV-1 survivors.

The severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1) survivors are more likely to produce a potent immune response to SARS-CoV-2 after booster vaccination. We assessed humoral and T cell responses against SARS-CoV-2 in previously vaccinated SARS-CoV-1 survivors and naïve healthy individuals (NHIs) after a booster Ad5-nCoV dose. Boosted SARS-CoV-1 survivors had a high neutralization of SARS-CoV-2 Wuhan-Hu-1 (WA1), Beta, and Delta but is limited to Omicron subvariants (BA.1, BA.2, BA.2.12.1, and BA.4/BA.5). Most boosted SARS-CoV-1 survivors had robust SARS-CoV-2-specific CD4+ and CD8+ T cell responses. While booster vaccination in NHIs elicited less or ineffective neutralization of WA1, Beta, and Delta, and none of them induced neutralizing antibodies against Omicron subvariants. However, they developed comparable SARS-CoV-2-specific T cell responses compared to boosted SARS-CoV-1 survivors. These findings suggest that boosted Ad5-nCoV would not elicit effective neutralizing antibodies against Omicron subvariants in SARS-CoV-1 survivors and NHIs but induced comparable robust T cell responses. Achieving a high antibody titer in SARS-CoV-1 survivors and NHIs is desirable to generate broad neutralization.

Persistence of Antibody and Cellular Immune Responses in Coronavirus Disease 2019 Patients Over Nine Months After Infection.

BACKGROUND: The duration of humoral and T and B cell response after the infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains unclear. METHODS: We performed a cross-sectional study to assess the virus-specific antibody and memory T and B cell responses in coronavirus disease 2019 (COVID-19) patients up to 343 days after infection. Neutralizing antibodies and antibodies against the receptor-binding domain, spike, and nucleoprotein of SARS-CoV-2 were measured. Virus-specific memory T and B cell responses were analyzed. RESULTS: We enrolled 59 patients with COVID-19, including 38 moderate, 16 mild, and 5 asymptomatic patients; 31 (52.5%) were men and 28 (47.5%) were women. The median age was 41 years (interquartile range, 30-55). The median day from symptom onset to enrollment was 317 days (range 257 to 343 days). We found that approximately 90% of patients still have detectable immunoglobulin (Ig)G antibodies against spike and nucleocapsid proteins and neutralizing antibodies against pseudovirus, whereas ~60% of patients had detectable IgG antibodies against receptor-binding domain and surrogate virus-neutralizing antibodies. The SARS-CoV-2-specific IgG+ memory B cell and interferon-γ-secreting T cell responses were detectable in more than 70% of patients. CONCLUSIONS: Severe acute respiratory syndrome coronavirus 2-specific immune memory response persists in most patients approximately 1 year after infection, which provides a promising sign for prevention from reinfection and vaccination strategy.

Transmission Potential of Asymptomatic and Paucisymptomatic Severe Acute Respiratory Syndrome Coronavirus 2 Infections: A 3-Family Cluster Study in China.

Data concerning the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in asymptomatic and paucisymptomatic patients are lacking. We report a 3-family cluster of infections involving asymptomatic and paucisymptomatic transmission. Eight of 15 (53%) members from 3 families were confirmed with SARS-CoV-2 infection. Of 8 patients, 3 were asymptomatic and 1 was paucisymptomatic. An asymptomatic mother transmitted the virus to her son, and a paucisymptomatic father transmitted the virus to his 3-month-old daughter. SARS-CoV-2 was detected in the environment of 1 household. The complete genomes of SARS-CoV-2 from the patients were > 99.9% identical and were clustered with other SARS-CoV-2 sequences reported from China and other countries.

Correction to: Is cell transplantation a reliable therapeutic strategy for spinal cord injury in clinical practice? A systematic review and meta-analysis from 22 clinical controlled trials.

Zhao-he and Sun-qingling are the co-first authors for this manuscript in the initial submission. Because of author's negligence and fault, this information was not shown clearly in the originally published article.

Is cell transplantation a reliable therapeutic strategy for spinal cord injury in clinical practice? A systematic review and meta-analysis from 22 clinical controlled trials.

PURPOSE: It is an open question whether cell transplantation can provide safety and effective outcome to spinal cord injury (SCI) patient which has remained controversial for almost 40 years. This study aimed to evaluate the safety and efficacy of cell transplantation in SCI patients. METHOD: Studies of the cell transplantation for SCI were retrieved from PubMed, Embase, Medline, Cochrane Library and analyzed quantitative data by Review Manager 5.3. RESULTS: Twenty-one clinical controlled studies with 973 patients were included. The pooled results suggested that cell transplantation significantly improved ASIA score, ASIA motor score, ASIA sensory score, Barthel Index score, residual urine volume, rehabilitative time of automatic micturition. Furthermore, subgroup analysis indicated that the stem cells exhibited more potent than the non-stem cells in spinal cord repair. Cell transplantation at more than 14 days after injury showed more significant improvements than that within 14 days from injury. The dosage of cell transplantation between 1-5 × 107 and 10-20 × 107 was the potent quantity for the patient with SCI. Intrathecal injection and intravenous + intrathecal injection showed more superior to the other method. The top 5 adverse events were febrile reaction (11.5%), neurologic pain (11.3%), headache (2.6%), neurologic deterioration (2.4%), and rigidity or spasticity (1.6%). CONCLUSION: Cell transplantation appears to be a safe therapeutic strategy possessing substantial beneficial effects in the patients with SCI in clinic. Moreover, treating SCI with stem cell, the dosage of cells between 1-5 × 107 and 10-20 × 107, in intermediate or chronic phase, minimally invasive techniques, may bring more advantage to SCI patient. These slides can be retrieved under Electronic Supplementary Material.

Long noncoding RNA TUG1 alleviates extracellular matrix accumulation via mediating microRNA-377 targeting of PPARγ in diabetic nephropathy.

Long noncoding RNA taurine-upregulated gene 1 (lncRNA TUG1) has been reported to play a key role in the progression of diabetic nephropathy (DN). However, the role of lncRNA TUG1 in the regulation of diabetic nephropathy remains largely unknown. The aim of the present study is to identify the regulation of lncRNA TUG1 on extracellular matrix accumulation via mediating microRNA-377 targeting of PPARγ, and investigate the underlying mechanisms in progression of DN. Microarray was performed to screen differentially expressed miRNAs in db/db DN mice. Afterwards, computational prediction programs (TargetScan, miRanda, PicTar and miRGen) was applied to predict the target gene of miRNAs. The complementary binding of miRNA and lncRNA was assessed by luciferase assays. Protein and mRNA expression were detected by western blot and real time quantitate PCR. MiRNA-377 was screened by miRNA microarray and differentially up-regulated in db/db DN mice. PPARγ was predicted to be the target of miR-377 and the prediction was verified by luciferase assays. Expression of miR-377 was up-regulated in mesangial cell treated with high glucose (25 mM), and overexpression of miR-377 inhibited PPARγ expression and promoted PAI-1 and TGF-ß1 expression. The expression of TUG1 antagonized the effect of miR-377 on the downregulation of its target PPARγ and inhibited extracellular matrix accumulation, including PAI-1, TGF-ß1, fibronectin (FN) and collagen IV (Col IV), induced by high glucose. LncRNA TUG1 acts as an endogenous sponge of miR-377 and downregulates miR-377 expression levels, and thereby relieving the inhibition of its target gene PPARγ and alleviates extracellular matrix accumulation of mesangial cells, which provides a novel insight of diabetic nephropathy pathogenesis.

[The Effect of Chronic Intermittent Hypoxia on Cognitive Function and Prefrontal Cortex Neurons in Rats].

OBJECTIVE: To determine the effect of chronic intermittent hypoxia on cognitive function and prefrontal cortex neurons in rats. METHODS: 48 adult male Wistar rats were randomly divided into two groups: control group and 50 mL/L intermittent hypoxia group (50 mL/L CIH). Rats in the CIH group were placed in the low oxygen tank, simulating intermittent hypoxia environment. At 7 d, 14 d, 21 d, and 28 d, the learning and memory ability of the rats was assessed with the Morris water maze (MWM) test; the expressions of cysteinyl aspartate specific protease (caspase)-8 protein in their prefrontal cortex were determined using Western blot method; the apoptosis of neurons was detected by the TdT mediated UTP nick end labeling (TUNEL) method. RESULTS: Compared with the controls, the CIH rats had significantly prolonged escape latency at 14 d, 21 d, and 28 d (P<0. 05) and decreased target quadrant time (P<0. 05). The prolonged escape latency increased and target quadrant time shortened with length of exposure to hypoxia (P<0. 05). Compared with controls, the CIH rats had gradually increased caspase-8 in their frontal cortex neurons, peaked at 28 d (P<0. 05). The CIH rats showed obvious structural damage and reduced neuron density in their frontal cortex neurons. They had higher levels of nerve cell apoptosis (P<0. 05), with apoptosis index increasing with length of exposure to hypoxia (P<0. 05). CONCLUSION: Severe chronic intermittent hypoxia can lead to pathological changes of frontal,cortex of rats, possibly

Expression of Caenorhabditis elegans-expressed Trans-HPS, partial aminopeptidase H11 from Haemonchus contortus.

Aminopeptidase H11 present in the surface of intestine microvilli in Haemonchus contortus was identified as the most effective antigen candidate. However, its recombinant forms produced in Escherichiacoli, insect cells and yeast could not provide promising protection against H. contortus challenge, probably due to the inappropriate glycosylation and/or conformational folding. Herein, partial H11 containing the potential zinc-binding domain and two predicted glycosylation sites (nt 1 bp-1710 bp, Trans-HPS) was subcloned downstream of 5' flanking region of Caenorhabditis elegans cpr-1 gene in pPD95.77 vector, with the deletion of GFP gene. The recombinant was expressed in C. elegans and verified by blotting with anti-H11 and anti-Trans-HPS rabbit polyclonal antibodies and anti-His monoclonal antibody. Stably inherited Trans-HPS in worm descendants was achieved by integration using UV irradiation. Immunization with the crude Trans-HPS extracted from transgenic worms resulted in 37.71% reduction in faecal egg counts (FEC) (P<0.05) and 24.91% reduction in worm burden, but an upward curve with moderate rate of daily FEC in goats. These results suggested an apparent delay against H. contortus egg-laying in goats, which differed from that with bacteria-origin form of partial H11 (nt 670 bp-1710 bp, HPS) (26.04% reduction in FEC and 18.46% reduction in worm burden). These findings indicate the feasibility of sufficient C. elegans-expressed H11 for the immunological research and vaccine development.

[Effect of adjuvant therapy with Dingguier umbilical paste on intestinal flora of diarrhea infants and its action characteristics].

The applicator therapy is a unique method to treat infant diarrhea in traditional Chinese medicines and widely applied in clinical practice. Currently, many researchers have proved the rationality of the therapy based on the traditional Chinese medicine mechanism and on the data from clinical practice, but its action mechanism is uncertain at present. In this study, with the assistance of pediatric practitioners, the automated ribosomal intergenic-spacer analysis (ARISA) was adopted to study the effect of the adjuvant therapy with Dingguier umbilical paste on intestinal flora of diarrhea infants, in which Dingguier umbilical paste served as the adjuvant therapy in oral traditional Chinese medicines and fecal samples of infants with different diarrhea symptoms were collected and used as the study materials. The results showed that the adjuvant therapy had a significant effect on the shift of intestinal flora, which was associated with the decrease in the similarity difference to the normal control group and the increase in the number of operational taxonomic units (OTUs) shared with the normal control group. Additionally, adjuvant therapy with Dingguier umbilical paste also showed long action duration and increased OTUs number. These results indicated that Dingguier umbilical paste has the effect in restoring the micro-ecosystem of unbalanced intestinal bacteria. Intestinal flora may be one of major targets for the applicator therapy for the infant diarrhea, but not for the single oral traditional Chinese medicine for infant diarrhea.

Two colistin resistance-producing Aeromonas strains, isolated from coastal waters in Zhejiang, China: characteristics, multi-drug resistance and pathogenicity.

Introduction: Aeromonas spp. are ubiquitous inhabitants of ecosystems, and many species are opportunistically pathogenic to humans and animals. Multidrug-resistant (MDR) Aeromonas species have been widely detected in hospitals, urban rivers, livestock, and aquatic animals. Results: In this study, we identified two Aeromonas isolates, namely Aeromonas veronii 0728Q8Av and Aeromonas caviae 1029Y16Ac, from coastal waters in Zhejiang, China. Both isolates exhibited typical biochemical characteristics and conferred MDR to 11 kinds of antibiotics, remaining susceptible to ceftazidime. Whole-genome sequencing revealed that both isolates harbored multiple antibiotic resistance genes (ARGs) and several mobile genetic elements (MGEs) on the chromosomes, each containing a resistance genomic island (GI), a typical class 1 integron, a transposon, and various insertion sequences (ISs). Most ARGs were situated within the multiple resistance GI, which contained a class 1 integron and a transposon in both Aeromonas isolates. Furthermore, a chromosomal mcr-3.16 gene was identified in A. veronii 0728Q8Av, while a chromosomal mcr-3.3 was found in A. caviae 1029Y16Ac. Both mcr-3 variants were not located within but were distanced from the multidrug resistance GI on the chromosome, flanking by multiple ISs. In addition, a mcr-3-like was found adjacent to mcr-3.16 to form a tandem mcr-3.16-mcr-3-like-dgkA structure; yet, Escherichia coli carrying the recombinants of mcr-3-like did not exhibit resistance to colistin. And an incomplete mcr-3-like was found adjacent to mcr-3.3 in A. caviae 1029Y16Ac, suggesting the possibility that mcr-3 variants originated from Aeromonas species. In vivo bacterial pathogenicity test indicated that A. veronii 0728Q8Av exhibited moderate pathogenicity towards infected ayu, while A. caviae 1029Y16Ac was non-virulent. Discussion: Thus, both Aeromonas species deserve further attention regarding their antimicrobial resistance and pathogenicity.

Parallel detection of multiple zoonotic parasites using a real-time fluorogenic loop-mediated isothermal amplification-based quadruple-sample microfluidic chip.

Zoonotic parasites pose significant health risks globally. In the present study, we combined a microfluidic chip with loop-mediated isothermal amplification (on-chip LAMP) to detect five zoonotic parasites: Toxoplasma gondii, Cryptosporidium parvum, Cryptosporidium hominis, Clonorchis sinensis, and Taenia solium. This method enabled the simultaneous parallel analysis of five genetic markers from a maximum of four samples per chip. The on-chip LAMP assay was conducted in a highly automated format via the addition (by pipetting) of each sample in a single operation. The reaction was performed in volumes as low as 5 µL at a temperature of 65°C for 60 min, achieving limits of detection ranging from 10-2 to 10-3 pg./µL of recombinant plasmid DNA. All the time-to-positive values were less than 40 min, and almost all the coefficients of variation were less than 10%, even when using limit of detection concentrations for multiple pathogens, indicating robust reproducibility among replicates. The clinical sensitivity and specificity for detecting 135 field samples were 98.08 and 97.59%, respectively, compared with traditional biological methods, indicating good applicability in the detection of field samples. This on-chip LAMP assay allows for low reagent consumption, ease of operation, and multiple analyses of samples and genetic targets, and is applicable for on-site detection and the routine monitoring of multiple zoonotic parasites.

SARS-CoV-2 vaccine-induced antibody and T cell response in SARS-CoV-1 survivors.

Preexisting immunity cross-reactive to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in SARS-CoV-1 survivors suggests that a coronavirus disease 2019 vaccine may boost such preexisting cross-reactive memory T cells. We measure SARS-CoV-2 and SARS-CoV-1 spike-specific neutralizing antibody and T cell responses in a single dose of Ad5-nCoV-immunized SARS-CoV-1 survivors 6 months after vaccination. Compared with Ad5-nCoV-immunized naive healthy individuals (NHIs), vaccination of Ad5-nCoV in SARS-CoV-1 survivors boosts the antibody response against SARS-CoV-1 but induces a limited neutralizing antibody that is capable of neutralizing SARS-CoV-2 variants of concern, and nearly all serum samples lose neutralization to Omicron subvariants. Immunized SARS-CoV-1 survivors produce a T cell response to SARS-CoV-2 comparable with that of Ad5-nCoV-immunized NHIs. However, a robust cross-reactive T cell response to SARS-CoV-1 is identified in immunized SARS-CoV-1 survivors compared with Ad5-nCoV-immunized NHIs. These findings suggest that vaccination with Ad5-nCoV elicits a stronger neutralizing antibody and cross-reactive T cell responses against SARS-CoV-1 in SARS-CoV-1 survivors.

Neutralizing immunity against SARS-CoV-2 Omicron BA.1 by infection and vaccination.

The emergence of the SARS-CoV-2 Omicron BA.1 (B.1.1.529) variant has raised questions regarding resistance to neutralizing antibodies elicited by natural infection or immunization. We examined the neutralization activity of sera collected from previously SARS-CoV-2-infected individuals and SARS-CoV-2 naive individuals who received BBIBP-CorV or CoronaVac to BA.1 and the earlier variants Alpha, Beta, and Delta. Both sera from convalescent patients over three months after infection and two-dose BBIBP-CorV or CoronaVac vaccine recipients barely inhibited BA.1, less effectively neutralized Beta and Delta, and moderately neutralized Alpha. However, administering a single dose of BBIBP-CorV or CoronaVac in previously infected individuals or a third dose booster vaccination of BBIBP-CorV or CoronaVac in previously vaccinated individuals enhances neutralizing activity against BA.1 and other variants, albeit with a lower antibody titer for BA.1. Our data suggest that a booster vaccination is important to broaden neutralizing antibody responses against the variants.

LncRNA AFAP1-AS1/miR-27b-3p/VEGF-C axis modulates stemness characteristics in cervical cancer cells.

BACKGROUND: Long non-coding RNA (lncRNA) actin filament-associated protein 1 antisense RNA 1 (AFAP1-AS1) functions as a competing endogenous RNA to regulate target genes expression by sponging microRNAs (miRs) to play cancer-promoting roles in cancer stem cells. However, the regulatory mechanism of AFAP1-AS1 in cervical cancer (CC) stem cells is unknown. The present study aimed to provide a new therapeutic target for the clinical treatment of CC. METHODS: Hyaluronic acid receptor cluster of differentiation 44 variant exon 6 (CD44v6)(+) CC cells were isolated by flow cytometry (FCM). Small interfering RNAs of AFAP1-AS1 (siAFAP1-AS1) were transfected into the (CD44v6)(+) cells. The levels of AFAP1-AS1 were measured by quantitative real-time PCR (qRT-PCR). Sphere formation assay, cell cycle analysis, and Western blotting were used to detect the effect of siAFAP1-AS1. RNA pull-down and luciferase reporter assay were used to verify the relationship between miR-27b-3p and AFAP1-AS1 or vascular endothelial growth factor (VEGF)-C. RESULTS: CD44v6(+) CC cells had remarkable stemness and a high level of AFAP1-AS1. However, AFAP1-AS1 knockdown with siAFAP1-AS1 suppressed the cell cycle transition of G(1)/S phase and inhibited self-renewal of CD44v6(+) CC cells, the levels of the stemness markers octamer-binding transcription factor 4 (OCT4), osteopontin (OPN), and cluster of differentiation 133 (CD133), and the epithelial-mesenchymal transition (EMT)-related proteins Twist1, matrix metalloprotease (MMP)-9, and VEGF-C. In the mechanism study, miR-27b-3p/VEGF-C signaling was demonstrated to be a key downstream of AFAP1-AS1 in the CD44v6(+) CC cells. CONCLUSIONS: LncRNA AFAP1-AS1 knockdown inhibits the CC cell stemness by upregulating miR-27b-3p to suppress VEGF-C.

The Factors Influencing the Renal Glucose Threshold in Patients with Newly Diagnosed Type 2 Diabetes Mellitus.

OBJECTIVE: This study aims to explore the factors influencing the renal glucose threshold (RTG) in patients with newly diagnosed type 2 diabetes mellitus (T2DM). METHODS: A cross-sectional study was conducted on 1009 hospitalized patients with T2DM using stratified random sampling. Blood glucose was monitored using a dynamic blood glucose monitor to obtain the mean blood glucose (MBG), which is used to calculate the RTG. The factors influencing the RTG were then analyzed. RESULTS: The mean RTG in patients with newly diagnosed T2DM was 203.58 ± 55.22 mg/dl. The correlation between the RTG and the various variables was analyzed, and the results demonstrated that the RTG was correlated with the patient's age (r = -0.14539, P = 0.0001); MBG (r = -0.35009, P = 0.0001); renal long neck (r = 0.16762, P = 0.0001); homeostatic model assessment for insulin resistance (r = -0.38322, P = 0.0001); homeostatic model assessment for beta-cell function (r = -0.22770, P = 0.0001); and the levels of glycated hemoglobin (HbA1c; r = 0.98994, P = 0.0001), blood urea nitrogen (r = -0.11093, P = 0.0004), creatinine (r = -0.26414, P = 0.0001), uric acid (r = -0.20149, P = 0.0001), total cholesterol (r = 0.13192, P = 0.0001), low-density lipoprotein (r = 0.12466, P = 0.0001), thyroid-stimulating hormone (r = -0.06346, P = 0.0460), beta-2 microglobulin (r = -0.08884, P = 0.0056), and 24-hour urine glucose (r = 0.32115, P = 0.0001). Multiple linear stepwise regression analysis revealed that the HbA1c, 24-hour urine glucose, estimated glomerular filtration rate (eGFR), D-dimer, and body mass index (BMI) should be included in the final model, and HbA1c had the greatest impact on the RTG followed in descending order by the 24-hour urine glucose, eGFR, D-dimer, and BMI (P < 0.05). CONCLUSION: The RTG increases in most patients with newly diagnosed diabetes. The risk factors for the RTG are HbA1c, 24-hour urine glucose, eGFR, D-dimer, and BMI.

Single-cell immune profiling reveals distinct immune response in asymptomatic COVID-19 patients.

While some individuals infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) present mild-to-severe disease, many SARS-CoV-2-infected individuals are asymptomatic. We sought to identify the distinction of immune response between asymptomatic and moderate patients. We performed single-cell transcriptome and T-cell/B-cell receptor (TCR/BCR) sequencing in 37 longitudinal collected peripheral blood mononuclear cell samples from asymptomatic, moderate, and severe patients with healthy controls. Asymptomatic patients displayed increased CD56briCD16- natural killer (NK) cells and upregulation of interferon-gamma in effector CD4+ and CD8+ T cells and NK cells. They showed more robust TCR clonal expansion, especially in effector CD4+ T cells, but lack strong BCR clonal expansion compared to moderate patients. Moreover, asymptomatic patients have lower interferon-stimulated genes (ISGs) expression in general but large interpatient variability, whereas moderate patients showed various magnitude and temporal dynamics of the ISGs expression across multiple cell populations but lower than a patient with severe disease. Our data provide evidence of different immune signatures to SARS-CoV-2 in asymptomatic infections.

Lasting antibody and T cell responses to SARS-CoV-2 in COVID-19 patients three months after infection.

The dynamics, duration, and nature of immunity produced during SARS-CoV-2 infection are still unclear. Here, we longitudinally measured virus-neutralising antibody, specific antibodies against the spike (S) protein, receptor-binding domain (RBD), and the nucleoprotein (N) of SARS-CoV-2, as well as T cell responses, in 25 SARS-CoV-2-infected patients up to 121 days post-symptom onset (PSO). All patients seroconvert for IgG against N, S, or RBD, as well as IgM against RBD, and produce neutralising antibodies (NAb) by 14 days PSO, with the peak levels attained by 15-30 days PSO. Anti-SARS-CoV-2 IgG and NAb remain detectable and relatively stable 3-4 months PSO, whereas IgM antibody rapidly decay. Approximately 65% of patients have detectable SARS-CoV-2-specific CD4+ or CD8+ T cell responses 3-4 months PSO. Our results thus provide critical evidence that IgG, NAb, and T cell responses persist in the majority of patients for at least 3-4 months after infection.

Persistence of H7N9 virus antibody response 2 years after infection.

We measured antibodies against H7N9 virus 2 years after infection in 14 patients who were infected during October 2016-September 2017. Approximately 2 years after infection, antibody titers ≥10 were detectable in 13 (92.9%) patients. Three (21.4%) of 14 patients had hemagglutination inhibition titers ≥40, and their geometric mean titer (GMT) was 20 (95% CI 15.7-28.1), whereas 10 (71.4%) and all 14 (100%) of the 14 patients had titers ≥40, and GMTs at 34.4 (95% CI 25.7-51.2) and 73.45 (54.7-106.7) for neuraminidase inhibition and microneutralization antibodies, respectively. Our findings suggest that H7N9 infection may induce long-term antibody response at least 2 years after infection.