Long-term efficacy of a recombinant hepatitis E vaccine in adults: 10-year results from a randomised, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: Hepatitis E virus (HEV) is a frequently overlooked causative agent of acute hepatitis. Evaluating the long-term durability of hepatitis E vaccine efficacy holds crucial importance. METHODS: This study was an extension to a randomised, double-blind, placebo-controlled, phase-3 clinical trial of the hepatitis E vaccine conducted in Dontai County, Jiangsu, China. Participants were recruited from 11 townships in Dongtai County. In the initial trial, a total of 112 604 healthy adults aged 16-65 years were enrolled, stratified according to age and sex, and randomly assigned in a 1:1 ratio to receive three doses of hepatitis E vaccine or placebo intramuscularly at month 0, month 1, and month 6. A sensitive hepatitis E surveillance system including 205 clinical sentinels, covering the entire study region, was established and maintained for 10 years after vaccination. The primary outcome was the per-protocol efficacy of hepatitis E virus vaccine to prevent confirmed hepatitis E occurring at least 30 days after administration of the third dose. Throughout the study, the participants, site investigators, and laboratory staff remained blinded to the treatment assignments. This study is registered with ClinicalTrials.gov (NCT01014845). FINDINGS: During the 10-year study period from Aug 22, 2007, to Oct 31, 2017, 90 people with hepatitis E were identified; 13 in the vaccine group (0·2 per 10 000 person-years) and 77 in the placebo group (1·4 per 10 000 person-years), corresponding to a vaccine efficacy of 83·1% (95% CI 69·4-91·4) in the modified intention-to-treat analysis and 86·6% (73·0 to 94·1) in the per-protocol analysis. In the subsets of participants assessed for immunogenicity persistence, of those who were seronegative at baseline and received three doses of hepatitis E vaccine, 254 (87·3%) of 291 vaccinees in Qindong at the 8·5-year mark and 1270 (73·0%) of 1740 vaccinees in Anfeng at the 7·5-year mark maintained detectable concentrations of antibodies. INTERPRETATION: Immunisation with this hepatitis E vaccine offers durable protection against hepatitis E for up to 10 years, with vaccine-induced antibodies against HEV persisting for at least 8·5 years. FUNDING: National Natural Science Foundation of China, Fujian Provincial Natural Science Foundation, Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences, and the Fundamental Research Funds for the Central Universities.

Environmental Impact Assessment for the Use of an Orally Aerosolized Adenovirus Type-5 Vector-Based COVID-19 Vaccine in Randomized Clinical Trials.

BACKGROUND: An orally aerosolized adenovirus type-5 vector-based coronavirus disease 2019 (COVID-19) vaccine (Ad5-nCoV) has recently been authorized for boosting immunization in China. Our study aims to assess the environmental impact of the use of aerosolized Ad5-nCoV. METHODS: We collected air samples from rooms, swabs from the desks on which the vaccine nebulizer was set, mask samples from participants, and blood samples of nurses who administered the inoculation in the clinical trials. The viral load of adenovirus type-5 vector in the samples and the antibody levels against the wild-type severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strain in serum were detected. RESULTS: Only one (4.00%) air sample collected before initiation of vaccination was positive and most air samples collected during and after vaccination were positive (97.96%, 100%, respectively). All nurses in trial A showed at least 4-fold increase of the neutralizing antibody against SARS-CoV-2 after initiation of the study. In trial B, the proportion of positive mask samples was 72.97% at 30 minutes after vaccination, 8.11% at day 1, and 0% at days 3, 5, and 7. CONCLUSIONS: Vaccination with the orally aerosolized Ad5-nCoV could result in some spillage of the vaccine vector viral particles in the environment and cause human exposure. Clinical Trials Registration. NCT04840992 and NCT05303584.

Final efficacy analysis, interim safety analysis, and immunogenicity of a single dose of recombinant novel coronavirus vaccine (adenovirus type 5 vector) in adults 18 years and older: an international, multicentre, randomised, double-blinded, placebo-controlled phase 3 trial.

BACKGROUND: The Ad5-nCoV vaccine is a single-dose adenovirus type 5 (Ad5) vectored vaccine expressing the SARS-CoV-2 spike protein that was well-tolerated and immunogenic in phase 1 and 2 studies. In this study, we report results on the final efficacy and interim safety analyses of the phase 3 trial. METHODS: This double-blind, randomised, international, placebo-controlled, endpoint-case driven, phase 3, clinical trial enrolled adults aged 18 years older at study centres in Argentina, Chile, Mexico, Pakistan, and Russia. Participants were eligible for the study if they had no unstable or severe underlying medical or psychiatric conditions; had no history of a laboratory-confirmed SARS-CoV-2 infection; were not pregnant or breastfeeding; and had no previous receipt of an adenovirus-vectored, coronavirus, or SARS-CoV-2 vaccine. After informed consent was obtained, 25 mL of whole blood was withdrawn from all eligible participants who were randomised in a 1:1 ratio to receive a single intramuscular dose of 0·5 mL placebo or a 0·5 mL dose of 5 × 1010 viral particle (vp)/mL Ad5-nCoV vaccine; study staff and participants were blinded to treatment allocation. All participants were contacted weekly by email, telephone, or text message to self-report any symptoms of COVID-19 illness, and laboratory testing for SARS-CoV-2 was done for all participants with any symptoms. The primary efficacy objective evaluated Ad5-nCoV in preventing symptomatic, PCR-confirmed COVID-19 infection occurring at least 28 days after vaccination in all participants who were at least 28 days postvaccination on Jan 15, 2021. The primary safety objective evaluated the incidence of any serious adverse events or medically attended adverse events postvaccination in all participants who received a study injection. This trial is closed for enrolment and is registered with ClinicalTrials.gov (NCT04526990). FINDINGS: Study enrolment began on Sept 22, 2020, in Pakistan, Nov 6, 2020, in Mexico, Dec 2, 2020, in Russia and Chile, and Dec 17, 2020, in Argentina; 150 endpoint cases were reached on Jan 15, 2021, triggering the final primary efficacy analysis. One dose of Ad5-nCoV showed a 57·5% (95% CI 39·7-70·0, p=0·0026) efficacy against symptomatic, PCR-confirmed, COVID-19 infection at 28 days or more postvaccination (21 250 participants; 45 days median duration of follow-up [IQR 36-58]). In the primary safety analysis undertaken at the time of the efficacy analysis (36 717 participants), there was no significant difference in the incidence of serious adverse events (14 [0·1%] of 18 363 Ad5-nCoV recipients and 10 [0·1%] of 18 354 placebo recipients, p=0·54) or medically attended adverse events (442 [2·4%] of 18 363 Ad5-nCoV recipients and 411 [2·2%] of 18 354 placebo recipients, p=0·30) between the Ad5-nCoV or placebo groups, or any serious adverse events considered related to the study product (none in both Ad5-nCoV and placebo recipients). In the extended safety cohort, 1004 (63·5%) of 1582 of Ad5-nCoV recipients and 729 (46·4%) of 1572 placebo recipients reported a solicited systemic adverse event (p<0·0001), of which headache was the most common (699 [44%] of Ad5-nCoV recipients and 481 [30·6%] of placebo recipients; p<0·0001). 971 (61·3%) of 1584 Ad5-nCoV recipients and 314 (20·0%) of 1573 placebo recipients reported an injection-site adverse event (p<0·0001), of which pain at the injection site was the most frequent; reported by 939 (59%) Ad5-nCoV recipients and 303 (19%) placebo recipients. INTERPRETATION: One dose of Ad5-nCoV is efficacious and safe in healthy adults aged 18 years and older. FUNDING: CanSino Biologics and the Beijing Institute of Biotechnology.

Safety and Immunogenicity of a Recombinant Adenovirus Type-5-Vectored Coronavirus Disease 2019 (COVID-19) Vaccine With a Homologous Prime-Boost Regimen in Healthy Participants Aged ≥6 Years: A Randomized, Double-Blind, Placebo-Controlled, Phase 2b Trial.

BACKGROUND: We assessed the safety and immunogenicity of a recombinant adenovirus type-5 (Ad5)-vectored coronavirus disease 2019 (COVID-19) vaccine with homologous prime-boost regimens in healthy participants aged ≥6 years. METHODS: In this randomized, double-blind, placebo-controlled trial, participants received vaccine or placebo 56 days apart. Enzyme-linked immunosorbent assay (ELISA) antibodies to the receptor binding domain (RBD) and pseudovirus neutralizing antibodies were detected. Adverse events were monitored for 28 days following each vaccination. RESULTS: A total of 430 participants were enrolled in the study, with 30 participants aged 18-55 years (MID cohort), 250 aged ≥56 years (OLD cohort), and 150 aged 6-17 years (MIN cohort). Ad5-vectored COVID-19 vaccine induced significant RBD-specific ELISA antibodies that decreased with increasing age, with geometric mean titers (GMTs) of 1037.5 in the MIN cohort, 647.2 in the MID cohort, and 338.0 in the OLD cohort receiving 5 × 1010 viral particles on day 28 following boost vaccination. Pseudovirus neutralizing antibodies showed a similar pattern, with GMTs of 168.0 in the MIN cohort, 76.8 in the MID cohort, and 79.7 in the OLD cohort. A single dose in children and adolescents induced higher antibody responses than that elicited by 2 doses in adults, with GMTs of 1091.6 and 96.6 for ELISA antibody and neutralizing antibody, respectively. Homologous prime-boost vaccination was safe and tolerable. CONCLUSIONS: Ad5-vectored COVID-19 vaccine with a single dose was safe and induced robust immune responses in children and adolescents aged 6-17 years. A prime-boost regimen needs further exploration for Ad5-vectored COVID-19 vaccine.Ad5-vectored COVID-19 vaccine with a single dose was safe and tolerated, and induced robust immune responses in children and adolescents aged 6-17 years. The boosting effect on immune responses of the homologous prime-boost regime given 56 days apart was limited. CLINICAL TRIALS REGISTRATION: NCT04566770.

Sensitivity, Specificity, and Safety of a Novel ESAT6-CFP10 Skin Test for Tuberculosis Infection in China: 2 Randomized, Self-Controlled, Parallel-Group Phase 2b Trials.

BACKGROUND: Diagnostics to identify tuberculosis infection are limited. We aimed to assess the diagnostic accuracy and safety of ESAT6-CFP10 (EC) skin test for tuberculosis infection in Chinese adults. METHODS: We conducted 2 randomized, parallel-group clinical trials in healthy participants and tuberculosis patients. All participants were tested with the T-SPOT.TB test, then received an EC skin test and tuberculin skin test (TST). The diameter of skin indurations and/or redness at injection sites were measured at different time periods. A bacillus Calmette Guerin (BCG) model was established to assess the diagnosis of tuberculosis infection using an EC skin test. RESULTS: In total, 777 healthy participants and 96 tuberculosis patients were allocated to receive EC skin test at 1.0 µg/0.1 mL or 0.5 µg/0.1 mL. The area under the curve was 0.95 (95% confidence interval [CI], .91-.97) for the EC skin test at 1.0 µg/0.1 mL at 24-72 hours. Compared with the T-SPOT.TB test, the EC skin test demonstrated similar sensitivity (87.5, 95% CI, 77.8-97.2 vs 86.5, 95% CI, 79.5-93.4) and specificity (98.9, 95% CI, 96.0-99.9 vs 96.1, 95% CI, 93.5-97.8). Among BCG vaccinated participants, the EC skin test had high consistency with the T-SPOT.TB test (96.3, 95% CI, 92.0-100.0). No serious adverse events related to the EC skin test were observed. CONCLUSIONS: The EC skin test demonstrated both high specificity and sensitivity at a dose of 1.0 µg/0.1 mL, comparable to the T-SPOT.TB test. The diagnostic accuracy of the EC skin test was not impacted by BCG vaccination. CLINICAL TRIALS REGISTRATION: NCT02389322 and NCT02336542.

Safety and immunogenicity of heterologous boost immunization with an adenovirus type-5-vectored and protein-subunit-based COVID-19 vaccine (Convidecia/ZF2001): A randomized, observer-blinded, placebo-controlled trial.

BACKGROUND: Heterologous boost vaccination has been proposed as an option to elicit stronger and broader, or longer-lasting immunity. We assessed the safety and immunogenicity of heterologous immunization with a recombinant adenovirus type-5-vectored Coronavirus Disease 2019 (COVID-19) vaccine (Convidecia, hereafter referred to as CV) and a protein-subunit-based COVID-19 vaccine (ZF2001, hereafter referred to as ZF). METHODS AND FINDINGS: We conducted a randomized, observer-blinded, placebo-controlled trial, in which healthy adults aged 18 years or older, who have received 1 dose of Convidecia, with no history of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, were recruited in Jiangsu, China. Sixty participants were randomly assigned (2:1) to receive either 1 dose of ZF2001 or placebo control (trivalent inactivated influenza vaccine (TIV)) administered at 28 days after priming, and received the third injection with ZF2001 at 5 months, referred to as CV/ZF/ZF (D0-D28-M5) and CV/ZF (D0-M5) regimen, respectively. Sixty participants were randomly assigned (2:1) to receive either 1 dose of ZF2001 or TIV administered at 56 days after priming, and received the third injection with ZF2001 at 6 months, referred to as CV/ZF/ZF (D0-D56-M6) and CV/ZF (D0-M6) regimen, respectively. Participants and investigators were masked to the vaccine received but not to the boosting interval. Primary endpoints were the geometric mean titer (GMT) of neutralizing antibodies against wild-type SARS-CoV-2 and 7-day solicited adverse reactions. The primary analysis was done in the intention-to-treat population. Between April 7, 2021 and May 6, 2021, 120 eligible participants were randomly assigned to receive ZF2001/ZF2001 (n = 40) or TIV/ZF2001 (n = 20) 28 days and 5 months post priming, and receive ZF2001/ZF2001 (n = 40) or TIV/ZF2001 (n = 20) 56 days and 6 months post priming. Of them, 7 participants did not receive the third injection with ZF2001. A total of 26 participants (21.7%) reported solicited adverse reactions within 7 days post boost vaccinations, and all the reported adverse reactions were mild, with 13 (32.5%) in CV/ZF/ZF (D0-D28-M5) regimen, 7 (35.0%) in CV/ZF (D0- M5) regimen, 4 (10.0%) in CV/ZF/ZF (D0-D56-M6) regimen, and 2 (10.0%) in CV/ZF (D0-M6) regimen, respectively. At 14 days post first boost, GMTs of neutralizing antibodies in recipients receiving ZF2001 at 28 days and 56 days post priming were 18.7 (95% CI 13.7 to 25.5) and 25.9 (17.0 to 39.3), respectively, with geometric mean ratios of 2.0 (1.2 to 3.5) and 3.4 (1.8 to 6.4) compared to TIV. GMTs at 14 days after second boost of neutralizing antibodies increased to 107.2 (73.7 to 155.8) in CV/ZF/ZF (D0-D28-M5) regimen and 141.2 (83.4 to 238.8) in CV/ZF/ZF (D0-D56-M6) regimen. Two-dose schedules of CV/ZF (D0-M5) and CV/ZF (D0-M6) induced antibody levels comparable with that elicited by 3-dose schedules, with GMTs of 90.5 (45.6, 179.8) and 94.1 (44.0, 200.9), respectively. Study limitations include the absence of vaccine effectiveness in a real-world setting and current lack of immune persistence data. CONCLUSIONS: Heterologous boosting with ZF2001 following primary vaccination with Convidecia is more immunogenic than a single dose of Convidecia and is not associated with safety concerns. These results support flexibility in cooperating viral vectored and recombinant protein vaccines. TRIAL REGISTRATION: Study on Heterologous Prime-boost of Recombinant COVID-19 Vaccine (Ad5 Vector) and RBD-based Protein Subunit Vaccine; ClinicalTrial.gov NCT04833101.

HTCC as a Polymeric Inhibitor of SARS-CoV-2 and MERS-CoV.

Among seven coronaviruses that infect humans, three (severe acute respiratory syndrome coronavirus [SARS-CoV], Middle East respiratory syndrome coronavirus [MERS-CoV], and the newly identified severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]) are associated with a severe, life-threatening respiratory infection and multiorgan failure. We previously proposed that the cationically modified chitosan N-(2-hydroxypropyl)-3-trimethylammonium chitosan chloride (HTCC) is a potent inhibitor of human coronavirus NL63 (HCoV-NL63). Next, we demonstrated the broad-spectrum antiviral activity of the compound, as it inhibited all low-pathogenicity human coronaviruses (HCoV-NL63, HCoV-229E, HCoV-OC43, and HCoV-HKU1). Here, using in vitro and ex vivo models of human airway epithelia, we show that HTCC effectively blocks MERS-CoV and SARS-CoV-2 infection. We also confirmed the mechanism of action for these two viruses, showing that the polymer blocks the virus entry into the host cell by interaction with the S protein.IMPORTANCE The beginning of 2020 brought us information about the novel coronavirus emerging in China. Rapid research resulted in the characterization of the pathogen, which appeared to be a member of the SARS-like cluster, commonly seen in bats. Despite the global and local efforts, the virus escaped the health care measures and rapidly spread in China and later globally, officially causing a pandemic and global crisis in March 2020. At present, different scenarios are being written to contain the virus, but the development of novel anticoronavirals for all highly pathogenic coronaviruses remains the major challenge. Here, we describe the antiviral activity of an HTCC compound, previously developed by us, which may be used as a potential inhibitor of currently circulating highly pathogenic coronaviruses-SARS-CoV-2 and MERS-CoV.

Safety, tolerability, and immunogenicity of a recombinant adenovirus type-5 vectored COVID-19 vaccine: a dose-escalation, open-label, non-randomised, first-in-human trial.

BACKGROUND: A vaccine to protect against COVID-19 is urgently needed. We aimed to assess the safety, tolerability, and immunogenicity of a recombinant adenovirus type-5 (Ad5) vectored COVID-19 vaccine expressing the spike glycoprotein of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strain. METHODS: We did a dose-escalation, single-centre, open-label, non-randomised, phase 1 trial of an Ad5 vectored COVID-19 vaccine in Wuhan, China. Healthy adults aged between 18 and 60 years were sequentially enrolled and allocated to one of three dose groups (5 × 1010, 1 × 1011, and 1·5 × 1011 viral particles) to receive an intramuscular injection of vaccine. The primary outcome was adverse events in the 7 days post-vaccination. Safety was assessed over 28 days post-vaccination. Specific antibodies were measured with ELISA, and the neutralising antibody responses induced by vaccination were detected with SARS-CoV-2 virus neutralisation and pseudovirus neutralisation tests. T-cell responses were assessed by enzyme-linked immunospot and flow-cytometry assays. This study is registered with ClinicalTrials.gov, NCT04313127. FINDINGS: Between March 16 and March 27, 2020, we screened 195 individuals for eligibility. Of them, 108 participants (51% male, 49% female; mean age 36·3 years) were recruited and received the low dose (n=36), middle dose (n=36), or high dose (n=36) of the vaccine. All enrolled participants were included in the analysis. At least one adverse reaction within the first 7 days after the vaccination was reported in 30 (83%) participants in the low dose group, 30 (83%) participants in the middle dose group, and 27 (75%) participants in the high dose group. The most common injection site adverse reaction was pain, which was reported in 58 (54%) vaccine recipients, and the most commonly reported systematic adverse reactions were fever (50 [46%]), fatigue (47 [44%]), headache (42 [39%]), and muscle pain (18 [17%]. Most adverse reactions that were reported in all dose groups were mild or moderate in severity. No serious adverse event was noted within 28 days post-vaccination. ELISA antibodies and neutralising antibodies increased significantly at day 14, and peaked 28 days post-vaccination. Specific T-cell response peaked at day 14 post-vaccination. INTERPRETATION: The Ad5 vectored COVID-19 vaccine is tolerable and immunogenic at 28 days post-vaccination. Humoral responses against SARS-CoV-2 peaked at day 28 post-vaccination in healthy adults, and rapid specific T-cell responses were noted from day 14 post-vaccination. Our findings suggest that the Ad5 vectored COVID-19 vaccine warrants further investigation. FUNDING: National Key R&D Program of China, National Science and Technology Major Project, and CanSino Biologics.

Immunogenicity and safety of a recombinant adenovirus type-5-vectored COVID-19 vaccine in healthy adults aged 18 years or older: a randomised, double-blind, placebo-controlled, phase 2 trial.

BACKGROUND: This is the first randomised controlled trial for assessment of the immunogenicity and safety of a candidate non-replicating adenovirus type-5 (Ad5)-vectored COVID-19 vaccine, aiming to determine an appropriate dose of the candidate vaccine for an efficacy study. METHODS: This randomised, double-blind, placebo-controlled, phase 2 trial of the Ad5-vectored COVID-19 vaccine was done in a single centre in Wuhan, China. Healthy adults aged 18 years or older, who were HIV-negative and previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection-free, were eligible to participate and were randomly assigned to receive the vaccine at a dose of 1 × 1011 viral particles per mL or 5 × 1010 viral particles per mL, or placebo. Investigators allocated participants at a ratio of 2:1:1 to receive a single injection intramuscularly in the arm. The randomisation list (block size 4) was generated by an independent statistician. Participants, investigators, and staff undertaking laboratory analyses were masked to group allocation. The primary endpoints for immunogenicity were the geometric mean titres (GMTs) of specific ELISA antibody responses to the receptor binding domain (RBD) and neutralising antibody responses at day 28. The primary endpoint for safety evaluation was the incidence of adverse reactions within 14 days. All recruited participants who received at least one dose were included in the primary and safety analyses. This study is registered with ClinicalTrials.gov, NCT04341389. FINDINGS: 603 volunteers were recruited and screened for eligibility between April 11 and 16, 2020. 508 eligible participants (50% male; mean age 39·7 years, SD 12·5) consented to participate in the trial and were randomly assigned to receive the vaccine (1 × 1011 viral particles n=253; 5 × 1010 viral particles n=129) or placebo (n=126). In the 1 × 1011 and 5 × 1010 viral particles dose groups, the RBD-specific ELISA antibodies peaked at 656·5 (95% CI 575·2-749·2) and 571·0 (467·6-697·3), with seroconversion rates at 96% (95% CI 93-98) and 97% (92-99), respectively, at day 28. Both doses of the vaccine induced significant neutralising antibody responses to live SARS-CoV-2, with GMTs of 19·5 (95% CI 16·8-22·7) and 18·3 (14·4-23·3) in participants receiving 1 × 1011 and 5 × 1010 viral particles, respectively. Specific interferon γ enzyme-linked immunospot assay responses post vaccination were observed in 227 (90%, 95% CI 85-93) of 253 and 113 (88%, 81-92) of 129 participants in the 1 × 1011 and 5 × 1010 viral particles dose groups, respectively. Solicited adverse reactions were reported by 183 (72%) of 253 and 96 (74%) of 129 participants in the 1 × 1011 and 5 × 1010 viral particles dose groups, respectively. Severe adverse reactions were reported by 24 (9%) participants in the 1 × 1011 viral particles dose group and one (1%) participant in the 5 × 1010 viral particles dose group. No serious adverse reactions were documented. INTERPRETATION: The Ad5-vectored COVID-19 vaccine at 5 × 1010 viral particles is safe, and induced significant immune responses in the majority of recipients after a single immunisation. FUNDING: National Key R&D Programme of China, National Science and Technology Major Project, and CanSino Biologics.

Serum Cytokine and Chemokine Profile in Relation to the Severity of Coronavirus Disease 2019 in China.

Coronavirus disease 2019 (COVID-19) is an emerging infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We investigated the serum cytokine and chemokine levels in asymptomatic, mild, moderate, severe, and convalescent SARS-CoV-2-infected cases. Proinflammatory cytokine and chemokine production induced by SARS-CoV-2 were observed not only in symptomatic patients but also in asymptomatic cases, and returned to normal after recovery. IL-6, IL-7, IL-10, IL-18, G-CSF, M-CSF, MCP-1, MCP-3, IP-10, MIG, and MIP-1α were found to be associated with the severity of COVID-19. Moreover, a set of cytokine and chemokine profiles were significantly higher in SARS-CoV-2-infected male than female patients. The serum levels of MCP-1, G-CSF, and VEGF were weakly and positively correlated with viral titers. We suggest that combinatorial analysis of serum cytokines and chemokines with clinical classification may contribute to evaluation of the severity of COVID-19 and optimize the therapeutic strategies.

Quorum sensing regulation confronts the development of a viable but non-culturable state in Vibrio cholerae.

Vibrio cholerae can enter a viable but non-culturable (VBNC) state when it encounters unfavourable environments; VBNC cells serve as important reservoirs and still pose threats to public health. The genetic regulation of V. cholerae entering its VBNC state is not well understood. Here, we show a confrontation strategy adapted by V. cholerae O1 in which it utilizes a quorum sensing (QS) system to prevent transition into a VBNC state under low nutrition and temperature conditions. The upregulation of hapR resulted in a prolonged culturable state of V. cholerae in artificial sea water at 4°C, whereas the mutation of hapR led to fast entry into the VBNC state. We also observed that different V. cholerae O1 natural isolates with distinct QS functions present a variety of abilities to maintain culturability during the transition to a VBNC state. The strain groups with higher or constitutive expression of QS genes exhibit a greater tendency to maintain the culturable state during VBNC induction than those lacking QS functional groups. In summary, HapR-mediated QS regulation is associated with the transition to the VBNC state in V. cholerae. HapR expression causes V. cholerae to resist VBNC induction and become dominant over competitors in changing environments.

A case-control study on the risk factors for hemorrhagic fever with renal syndrome.

BACKGROUND: Hemorrhagic fever with renal syndrome (HFRS) is an endemic communicable disease in China, accounting for 90% of total reported cases worldwide. In this study, the authors want to investigate the risk factors for HFRS in recent years to provide the prevention and control advices. METHODS: A community-based, 1:2 matched case-control study was carried out to investigate the risk factors for HFRS. Cases were defined as laboratory-confirmed cases that tested positive for hantavirus-specific IgM antibodies. Two neighbourhood controls of each case were selected by sex, age and occupation. Standardized questionnaires were used to collect information and identify the risk factors for HFRS. RESULTS: Eighty-six matched pairs were investigated in the study. The median age of the cases was 55.0 years, 72.09% were male, and 73.26% were farmers. In the multivariate logistic regression analysis, cleaning spare room at home (OR = 3.310, 95%CI 1.335-8.210) was found to be risk factor for infection; storing food and crops properly (OR = 0.279 95%CI 0.097-0.804) provided protection from infection. CONCLUSION: Storing food and crops properly seemed to be protective factor, which was important for HFRS prevention and control. More attention should be paid to promote comprehensive health education and behaviour change among high-risk populations in the HFRS endemic area.

Immunogenicity and Safety of a Sabin Strain-Based Inactivated Polio Vaccine: A Phase 3 Clinical Trial.

BACKGROUND: The Sabin strain-based inactivated polio vaccine (sIPV) plays a vital role in eradicating poliomyelitis in developing countries. METHODS: The study was designed as a randomized, controlled, double-blinded, noninferiority trial. A total of 1200 healthy infants aged 60-90 days were enrolled and randomly assigned to receive 3 doses of either sIPV (the experimental arm) or IPV (the control arm) at days 0, 30, and 60. Immunogenicity and safety outcomes were assessed using the per-protocol and safety populations, respectively. RESULTS: A total of 553 and 562 participants in the sIPV and IPV groups, respectively, were included in the per-protocol population. Seroconversion rates in the sIPV and IPV groups were 98.0% and 94.1%, respectively, for type 1 poliovirus (P < .01); 94.8% and 84.0%, respectively, for type 2 (P < .01); and 98.9% and 97.7%, respectively, for type 3 (P = .11). A total of 599 and 600 participants in the sIPV and IPV groups, respectively, were included in the safety population. Fever was the most common adverse event, occurring in 61.6% and 49.8% of participants in the experimental and control arms, respectively (P < .01). CONCLUSIONS: The sIPV demonstrated an immunogenicity profile noninferior to that of the conventional IPV and had a good safety profile. CLINICAL TRIALS REGISTRATION: NCT03526978.

Rapid detection of human mastadenovirus species B by recombinase polymerase amplification assay.

BACKGROUND: As an important component of the causative agent of respiratory tract infections, enteric and eye infections, Human mastadenoviruses (HAdVs) species B spread easily in the crowd. In this study, we developed a recombinase polymerase amplification (RPA) assay for rapidly detecting HAdVs species B which was comprised of two different formats (real-time and lateral-flow device). RESULTS: This assay was confirmed to be able to detect 5 different HAdVs species B subtypes (HAdV-B3, HAdV-B7, HAdV-B11, HAdV-B14 and HAdV-B55) without cross-reactions with other subtypes and other respiratory tract pathogens. This RPA assay has not only highly sensitivity with low detection limit of 50 copies per reaction but also short reaction time (< 15 min per detection). Furthermore, the real-time RPA assay has excellent correlation with real-time PCR assay for detection of HAdVs species B presented in clinical samples. CONCLUSIONS: Thus, the RPA assay developed in this study provides an effective and portable approach for the rapid detection of HAdVs species B.

Hepatitis B virus infection and risk of non-alcoholic fatty liver disease: A population-based cohort study.

BACKGROUND & AIMS: Although non-alcoholic fatty liver disease (NAFLD) has been studied extensively, the potential risk factors for NAFLD among chronic hepatitis B (CHB) patients have not been fully known. METHODS: A population-based cohort of adult CHB patients without a history of alcohol drinking or NAFLD were recruited and followed up from October 2012 to January 2015 in Jiangsu province, China. Using Cox proportional hazards regression model, potential risk factors including viral and metabolic factors for NAFLD were evaluated. RESULTS: Two thousand three hundred and ninety-three adult CHB patients (mean age 50.7 ± 13.2 years) were included in the cohort. With 4429 person-years of follow-up, 283 individuals progressed to NAFLD with an incidence rate of 63.89/1000 person-years. Overweight and obese CHB patients had an increased risk of NAFLD (overweight adjusted hazard ratio [HR], 3.10; 95% CI, 2.29-4.18; obese HR, 8.52; 95%CI, 5.93-12.25) compared to normal weight carriers. The incidence of NAFLD was associated with concurrent type 2 diabetes mellitus (DM) (HR, 1.88; 95%CI, 1.15-3.08). However, no associations between viral factors with NAFLD incidence rate were identified. In a subgroup of participants with concurrent type 2 DM, detectable HBV DNA levels were negatively associated with the development of NAFLD (HR, 0.37; 95%CI, 0.14-0.98). There was super-multiplicative interaction between BMI and gender with respect to incidence of NAFLD, with an ROR of 2.08 (95%CI, 1.02-4.23). CONCLUSION: Metabolic factors play an important role in the presence of NAFLD among Chinese CHB patients. However, viral replication factors are not related to NAFLD except among those with concurrent type 2 DM.

Establishment and development of national community-based collaborative innovation demonstration areas to achieve the control target of hepatitis B in China.

BACKGROUND: The major infectious diseases of hepatitis B has constituted an acute public health challenge in China. An effective and affordable HBV control model is urgently needed. A national project of Community-based Collaborative Innovation HBV (CCI-HBV) demonstration areas has optimized the existing community healthcare resources and obtained initial results in HBV control. METHODS: Based on the existing community healthcare network, CCI-HBV project combined the community health management and health contract signing service for long-staying residents in hepatitis B screening. Moreover, HBV field research strategy was popularized in CCI-HBV areas. After screening, patients with seropositive results were enrolled in corresponding cohorts and received treatment at an early stage. And the uninfected people received medical supports including health education through new media, behavior intervention and HBV vaccinations. In this process, a cloud-based National Information Platform (NIP) was established to collect and store residents' epidemiological data. In addition, a special quality control team was set up for CCI project. RESULTS: After two rounds of screening, HBsAg positive rate dropped from 5.05% (with 5,173,003 people screened) to 4.57% (with 3,819,675 people screened), while the rate of new HBV infections was 0.28 per 100 person-years in the fixed cohorts of 2,584,322 people. The quality control team completed PPS sampling simultaneously and established the serum sample database with 2,800,000 serum samples for unified testing. CONCLUSIONS: CCI-HBV project has established a large-scale field research to conduct whole-population screening and intervention. We analyzed the HBsAg prevalence and new infection rate of HBV in the fixed population for the epidemic trend and intervention effect. The purpose of CCI-HBV project is to establish and evaluate a practical model of grid management and field strategy, to realize the new goal to control hepatitis B in China. To provide policymakers with a feasible model, our results are directly applicable. TRIAL REGISTRATION: The project was funded by the Major Projects of Science Research for the 11th and 12th five-year plans of China, entitled "The prevention and control of AIDS, viral hepatitis and other major infectious diseases", Grant Nos. 2009ZX10004901, 2011ZX10004901, 2013ZX10004904, 2014ZX10004007 and 2014ZX10004008.

Fine mapping the MHC region identified four independent variants modifying susceptibility to chronic hepatitis B in Han Chinese.

Several genome-wide association studies (GWAS) have demonstrated the association between genetic variants in the major histocompatibility complex (MHC) region and chronic hepatitis B (CHB) virus infection, but it is still unknown about the disease-causing loci and potential mechanisms owing to the complicated linkage disequilibrium for this region. To systematically characterize the MHC variations in relation to the CHB infection, we fine mapped the MHC region on our existing GWAS data with SNP2HLA taken the Pan-Asian panel as reference and finally identified four independent associations. The HLA-DPß1 amino acid positions 84-87, which drove the effect of reported single nucleotide polymorphisms rs9277535 and rs3077, showed the most significant association (OR = 0.65, P = 2.03 × 10(-8)). The Leu-15 of HLA-C, conferring the effect of rs3130542, increased the risk of CHB infection independently (OR = 1.61, P = 3.42 × 10(-7)). The HLA-DRß1*13, in perfect LD with glutamic at site 71, and rs400488, an expression quantitative trait locus for HLA-J, were newly identified to be associated with CHB infection independently (OR = 1.84, P = 3.84 × 10(-9); OR = 0.28, P = 6.27 × 10(-7), respectively). HLA-DPß1 positions 84-87 and HLA-DRß1 position 71 implicated the P1 and P4 in the antigen-binding groove, whereas HLA-C position 15 affected the signal peptide. These four independent loci together can explain ∼ 6% of the phenotypic variance for CHB infection, accounting for 72.94% of that explained by known genetic variations. We fine mapped the MHC region and identified four loci that independently drove the chronic HBV infection. The results provided a deeper understanding of the GWAS signals and identified additional susceptibility loci which were missed in previous association studies.

Safety and immunogenicity of a recombinant adenovirus type-5 vector-based Ebola vaccine in healthy adults in Sierra Leone: a single-centre, randomised, double-blind, placebo-controlled, phase 2 trial.

BACKGROUND: A recombinant adenovirus type-5 vector-based vaccine expressing the glycoprotein of Ebola Zaire Makona variant showed good safety and immunogenicity in a phase 1 trial of healthy Chinese adults. We aimed to assess the safety and immunogenicity of this vaccine in healthy adults in Sierra Leone and to determine the optimal dose. METHODS: We did a single-centre, randomised, double-blind, placebo-controlled, phase 2 clinical trial at Sierra Leone-China Friendship Hospital, Freetown, Sierra Leone. We recruited healthy adults aged 18-50 years who were HIV negative, had no history of Ebola virus infection, and had no previous immunisation with other Ebola vaccine candidates. Participants were sequentially enrolled and randomly assigned (2:1:1), by computer-generated block randomisation (block size of eight), to receive the high-dose vaccine (1·6 × 1011 viral particles), low-dose vaccine (8·0 × 1010 viral particles), or placebo (containing only vaccine excipients, with no viral particles). Participants, investigators, and study staff (except two study pharmacists) were masked from treatment allocation. The primary safety outcome was occurrence of solicited adverse reactions within 7 days of vaccination, analysed by intention to treat. The primary immunogenicity outcome was glycoprotein-specific antibody responses at days 14, 28, and 168 after vaccination, analysed in all vaccinated participants who had blood samples drawn for antibody tests. The trial is registered with the Pan African Clinical Trials Registry, number PACTR201509001259869, and is completed. FINDINGS: During Oct 10-28, 2015, 500 participants were enrolled and randomly assigned to receive the high-dose vaccine (n=250), low-dose vaccine (n=125), or placebo (n=125). 132 (53%) participants in the high-dose group, 60 (48%) in the low-dose group, and 54 (43%) in the placebo group reported at least one solicited adverse reaction within 7 days of vaccination. Most adverse reactions were mild and self-limiting. Solicited injection-site adverse reactions were significantly more frequent in vaccine recipients (65 [26%] in high-dose group and 31 [25%] in low-dose group) than in those receiving placebo (17 [14%]; p=0·0169). Glycoprotein-specific antibody responses were detected from day 14 onwards (geometric mean titre 1251·0 [95% CI 976·6-1602·5] in low-dose group and 1728·4 [1459·4-2047·0] in high-dose group) and peaked at day 28 (1471·8 [1151·0-1881·8] and 2043·1 [1762·4-2368·4]), but declined quickly in the following months (223·3 [148·2-336·4] and 254·2 [185·0-349·5] at day 168). Geometric mean titres in the placebo group remained around 6·0-6·8 throughout the study period. Three serious adverse events (malaria, gastroenteritis, and one fatal asthma episode) were reported in the high-dose vaccine group, but none was deemed related to the vaccine. INTERPRETATION: The recombinant adenovirus type-5 vector-based Ebola vaccine was safe and highly immunogenic in healthy Sierra Leonean adults, and 8·0 × 1010 viral particles was the optimal dose. FUNDING: Chinese Ministry of Science and Technology and the National Health and Family Planning Commission, Beijing Institute of Biotechnology, and Tianjin CanSino Biotechnology.

Long-term efficacy of a hepatitis E vaccine.

BACKGROUND: Hepatitis E virus (HEV) is a leading cause of acute hepatitis. The long-term efficacy of a hepatitis E vaccine needs to be determined. METHODS: In an initial efficacy study, we randomly assigned healthy adults 16 to 65 years of age to receive three doses of either a hepatitis E vaccine (vaccine group; 56,302 participants) or a hepatitis B vaccine (control group; 56,302 participants). The vaccines were administered at 0, 1, and 6 months, and the participants were followed for 19 months. In this extended follow-up study, the treatment assignments of all participants remained double-blinded, and follow-up assessments of efficacy, immunogenicity, and safety were continued for up to 4.5 years. RESULTS: During the 4.5-year study period, 60 cases of hepatitis E were identified; 7 cases were confirmed in the vaccine group (0.3 cases per 10,000 person-years), and 53 cases in the control group (2.1 cases per 10,000 person-years), representing a vaccine efficacy of 86.8% (95% confidence interval, 71 to 94) in the modified intention-to-treat analysis, rather than (95% confidence interval, 71 to 84) [corrected]. Of the participants who were assessed for immunogenicity and were seronegative at baseline, 87% of those who received three doses of the hepatitis E vaccine maintained antibodies against HEV for at least 4.5 years; HEV antibody titers developed in 9% in the control group. The rate of adverse events was similar in the two groups. CONCLUSIONS: Immunization with this hepatitis E vaccine induced antibodies against HEV and provided protection against hepatitis E for up to 4.5 years. (Funded by the Chinese Ministry of Science and Technology and others; ClinicalTrials.gov number, NCT01014845.).