Safety and immunogenicity of SW-BIC-213, a modified COVID-19 Lipo-Polyplex mRNA vaccine, in Laotian healthy adults aged 18 years and above: a Phase 1/2 trial (preprint)

Background The mRNA vaccine against SARS-CoV-2 has demonstrated remarkable efficacy in protecting against coronavirus disease 2019 (COVID-19), including providing high protection against severe disease during the emergence of variant waves. In this study, we aimed to investigate the safety and immunogenicity of a 2-dose regimen of the LPP-based mRNA vaccine, SW-BIC-213, in Laos. Methods For this phase 1/2 clinical trial, we recruited healthy adults aged 18-60 years (phase 1) or [≥]18 years (phase 2) from Mahosot Hospital (Vientiane) and Champhone District Hospital (Savannakhet). Participants with SARS-CoV-2 infection, previous COVID-19 vaccination, known allergies to any vaccine component, or pregnancy were excluded. In the phase 1 trial, 41 eligible participants were sequentially assigned to either the 25 g dose group (25 g) or the 45 g dose group (45 g) in accordance with their enrollment order, with 21 participants in 45 g dose group and 20 participants in 25 g dose group. In the phase 2 trial, 480 participants were randomly allocated (2:2:1 ratio) to either the 25 g dose group, 45 g dose group, or placebo group. The primary endpoints for the phase 1 trial were the incidence of local/systemic solicited adverse reactions/events (0-6 days after each vaccination dose), unsolicited adverse events (0-21 days and 0-28 days after the first and second dose of immunization, respectively), and serious adverse events from the first dose of vaccination to 28 days after completing the full course of immunization. In the phase 2 trial, the primary endpoints were the seroconversion rate and geometric mean titer (GMT) of SARS-CoV-2 S-protein specific IgG antibodies and neutralizing antibodies 14 days after the second dose in participants. As for neutralizing antibodies, we detected pseudo-virus neutralizing antibody against wild type (WT), Delta, BA.1 and BA.2. We also detected live viral neutralizing antibody against WT strain 14 days after the second dose. Furthermore, the safety endpoints were also measured during the trial. This seamless phase 1/2 trial was registered with ClinicalTrials.gov under the identifier NCT05144139. Results Between December 3, 2021, and March 31, 2022, a total of 41 participants were recruited in the phase 1 trial, while the phase 2 trial enrolled 480 participants from January 20 to July 6, 2022. In the phase 1 trial, a total of 32 subjects (80.0%) reported 103 cases of adverse reactions. All adverse reactions were limited to Grade 1-2. In the phase 2 trial, a total of 479 subjects, 372 subjects (77.7%) reported 929 cases of adverse reactions. All adverse reactions in severity of Grade 3 were manifested as fever (3.4%, 2.1% and 2.9% in 45 g dose, 25 g dose and placebo group respectively, only observed in adults), except which all other reactions were limited to Grade 1-2. All adverse reactions noted during the study were tolerable, predominantly transient, and resolved spontaneously. No serious adverse events (SAEs) related to vaccination were observed. In Phase 2 study, SW-BIC-213 could elicit a high level of seroconversion rate of pseudo-virus neutralizing antibody against WT (100.0% in 25 g dose group, 99.3% in 45 g dose group), Delta (99.2% in 25 g dose group, 98.0% in 45 g dose group), Omicron BA.1 (84.1% in 25 g dose group, 84.7% in 45 g dose group) and Omicron BA.2 (96.0% in 25 g dose group, 88.8% in 45 g dose group) at 14 days after the second dose. The pseudo-virus neutralizing antibody titer against WT, Delta, BA.1 and BA.2 was all significant higher (P<0.0001) in both 45 g dose group (1175.02, 620.62, 72.39 and 172.80) and 25 g dose group (885.80, 579.40, 47.24 and 101.96) compared with the placebo group (9.67, 10.66, 13.99 and 29.53) at 14 days after the second dose. As for live viral neutralizing antibodies against WT strain, the seroconversion rate could reach more than 94% at 14 days after second dose. The neutralizing antibody titer against WT strain was significantly higher (P<0.0001) in both 45 g dose group (315.00) and 25 g dose group (323.18) compared with the placebo group (8.51) at 14 days after second dose. Conclusion: COVID-19 mRNA vaccine SW-BIC-213 manifests a favorable safety profile and is highly immunogenic in eligible subjects aged [≥]18 years.

Antibody Persistence and Safety through 6 Months after Heterologous Orally Aerosolised Ad5-nCoV in individuals primed with two-dose CoronaVac previously (preprint)

Background: Heterologous orally administered adenovirus type-5 vector-based COVID-19 vaccine (Ad5-nCoV) in individuals who were primed with two-dose CoronaVac (an inactivated SARS-CoV-2 vaccine, by Sinovac) previously, has been reported to be safe and highly immunogenic within 28 days post-boosting. However, antibody persistence and safety up to 6 months of this regimen are not been reported yet. Methods: This is a randomized, open label, single-center trial on safety and immunogenicity of heterologous boost immunization with an orally administered aerosolised Ad5-nCoV vs. homologous boost immunization with CoronaVac after two-dose priming with CoronaVac in Chinese adults aged 18 years and older (NCT05043259). We followed the participants in this trial, including 140 in the low-dose aerosolised Ad5-nCoV group, 139 in the high-dose aerosolised Ad5-nCoV group, and 140 in the CoronaVac group for 6 months. Neutralising antibodies (NAbs) against live wild-type SARS-CoV-2 virus and omicron variant, and receptor-binding domain (RBD)-specific IgG antibodies were detected in serum samples collected at 28 days, 3 months, and 6 months after the booster dose. Serious adverse events (SAEs) were documented till month 6. Results: The low-dose and high-dose heterologous boost immunisation groups had NAb GMTs against live wild-type SARS-CoV-2 of 1937.3 [95% CI 1466.9, 2558.4] and 1350.8 [95% CI 952.6, 1915.3], which were 26.4 folds and 18.4 folds higher than that the CoronaVac group did (73.5 [95%CI 52.3, 103.3]) at 28 days. The low-dose and high-dose heterologous boost immunisation groups had NAb GMTs against live wild-type SARS-CoV-2 of 530.1 (95% CI 412.5, 681.1) and 457.6 (95%CI 349.4, 599.2), which were 26.0 folds and 22.4 folds higher than that the CoronaVac group did (20.4 [95%CI 14.3, 29.1]) at 3 months, respectively. At 6 months, the low-dose and high-dose heterologous booster groups had NAb GMTs against live wild-type SARS-CoV-2 of 312.9 (95%CI 237.7, 411.8) and 251.1 (95%CI 178.2, 354.0), which were 30.1 folds and 24.1 folds higher than the CoronaVac group did (10.4 [95%CI 7.8, 14.0]), respectively. Additionally, the low-dose and high-dose heterologous booster groups had NAb GMTs against live omicron variant of 52.0 (95%CI 37.2, 72.6) and 23.1 (95%CI 15.7, 33.9) at 28 days, 27.9 (95% CI 18.8, 41.3) and 23.3 (95%CI 16.2, 33.3) at 3 months, 16.0 (95%CI 10.9, 23.5) and 12.0 (95%CI 8.5, 16.8) at 6 months, respectively. However, nearly all participants had no detectable NAbs for omicron variant in the CoronaVac group at either 28 days, 3 months, or 6 months. No vaccine-related SAEs were observed. Conclusions: These data suggested that heterologous aerosolised Ad5-nCoV following two-dose CoronaVac priming was safe and persistently more immunogenic than three-dose CoronaVac, although immune responses waned over time.

Heterologous CoronaVac plus Ad5-nCOV versus homologous CoronaVac vaccination among elderly: a phase 4, non-inferiority, randomized study (preprint)

Importance People over 60 developed less protection after two doses of inactivated COVID-19 vaccine than younger people. Heterologous vaccination might provide greater immunity and protection against variants of concern. Objective To assess the safety and immunogenicity of a heterologous immunization with an adenovirus type 5-vectored vaccine (Convidecia) among elderly who were primed with an inactivated vaccine (CoronaVac) previously. Design An observer-blind, randomized (1:1) trial, conducted from August 26 to November 13, 2021. Setting A single center in Jiangsu Province, China. Participants 299 participants aged 60 years and olderof them 199 primed with two doses of CoronaVac in the past 3-6 months and 100 primed with one dose of CoronaVac in the past 1-2 months. Intervention Convidecia or CoronaVac as boosting dose Main Outcomes and Measures Geometric mean titers (GMTs) of neutralizing antibodies against wild-type SARS-CoV-2, and Delta and Omicron variants 14 days post boosting, and adverse reactions within 28 days. Results In the three-dose regimen cohort (n=199; mean (SD) age, 66.7 (4.2) years; 74 (37.2%) female), 99 and 100 received a third dose of Convidecia (group A) and CoronaVac (group B), respectively. In the two-dose regimen cohort (n=100; mean (SD) age, 70.5 (6.0) years; 49 (49%) female), 50 and 50 received a second dose of Convidecia (group C) and CoronaVac (group D), respectively. GMTs of neutralizing antibodies against wild-type SARS-CoV-2 at day 14 were 286.4 (95% CI: 244.6, 335.2) in group A and 48.2 (95% CI: 39.5, 58.7) in group B, with GMT ratio of 6.2 (95% CI: 4.7, 8.1), and 70.9 (95% CI: 49.5, 101.7) in group C and 9.3 (95% CI: 6.2, 13.9) in group D, with GMT ratio of 7.6 (95% CI: 4.1, 14.1). There was a 6.3-fold (GMTs, 45.9 vs 7.3) and 7.5-fold (32.9 vs 4.4) increase in neutralizing antibodies against Delta and Omicron variants in group A, respectively, compared with group B. However, there was no significant difference between group C and group D. Both heterologous and homologous booster immunizations were safe and well tolerated. Conclusions and Relevance Heterologous prime-boost regimens with CoronaVac and Convidecia induced strong neutralizing antibodies in elderly, which was superior to that induced by the homologous boost, without increasing safety concerns. Trial Registration Clinical Trials.gov NCT04952727

The preliminary safety and immunogenicity results of a randomized, double-blind, placebo-controlled Phase I trial for a recombinant two-component subunit SARS-CoV-2 vaccine ReCOV (preprint)

Summary Background The ReCOV is a recombinant trimeric two-component SARS-CoV-2 subunit vaccine adjuvanted with BFA03. We report the preliminary safety and immunogenicity results for the ReCOV. Methods This first in human, randomized, double-blind, placebo-controlled phase I study, was conducted at 2 study sites in New Zealand. Subjects were stratified into two age cohorts (18-55 years and 56-80 years old) and then randomly assigned in a 4:1 ratio to receive two 0.5 mL intramuscular doses of the ReCOV vaccine (20µg or 40µg, adjuvanted with BFA03 in each) or placebo, 21 days apart. The primary endpoints were incidence of solicited local and systemic adverse events (AEs) and unsolicited AEs after each dose; incidence of serious adverse events (SAEs) up to 30 days after the second dose; changes in clinical laboratory tests from baseline up to 7 days after each dose; and changes in vital signs from baseline up to 30 days after the second dose. The key secondary endpoints for immunogenicity were neutralizing antibody titers against SARS-CoV-2, S1 receptor binding domain (RBD) and N-terminal domain (NTD) IgG titers post-vaccination. The T cell-specific immune response elicited by ReCOV were also evaluated. The trial was registered with ClinicalTrials.gov ( NCT04818801 ). Findings One hundred participants (50 for each age group) were randomized. The incidence of solicited local AEs in 20μg ReCOV, 40μg ReCOV, and pooled placebo group among younger adults were 60.0%, 70.0%, and 10.0%, respectively, while among older adults were 55.0%, 84.2%, and 10.0%, respectively. The incidence of solicited systemic AEs in 20μg ReCOV, 40μg ReCOV, and pooled placebo group among younger adults were 60.0%, 60.0%, and 30.0%, respectively, while among older adults were 50.0%, 52.6%, and 50.0%, respectively. All solicited AEs and unsolicited AEs were mild. No vaccination-related SAE, adverse events of special interest, and AE leading to early discontinuation were reported. ReCOV elicited SARS-CoV-2 neutralizing antibody after the first vaccination, which were increased further after the second vaccination irrespective of dose and age groups. The neutralizing antibody against wild-type SARS-CoV-2 peaked at 14 days post the second vaccination in both 20µg and 40µg ReCOV groups, with GMT of 1643.17 IU/mL and 1289.21 IU/mL among younger adults, and 1122.32 IU/mL and 680.31 IU/mL among older adults, respectively. Similarly, both anti-RBD and anti-NTD specific IgG were elicited after the first vaccination, and peaked at 14 days after the second vaccination. T helper 1 biased cellular responses were observed after ReCOV vaccinations. Interpretation Both 20 and 40µg ReCOV showed good safety profiles and elicited strong immune responses in the younger and the older adults. The results of this study support the accelerated development of ReCOV. Funding Jiangsu Recbio Technology Co., Ltd.

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 (preprint)

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 COVID-19 vaccine (Convidecia) and a protein-subunit-based COVID-19 vaccine (ZF2001). Methods and Findings We did a randomized, observer-blinded, placebo-controlled trial in healthy adults previously received one dose of Convidecia. Participants were randomly assigned (2:1) to receive either ZF2001 (vaccine group) or a trivalent inactivated influenza vaccine (TIV) (placebo group) at either 28-day or 56-day intervals. For both regimens, all participants received the 2nd injection with ZF2001 at 4 months after a dose of ZF2001 or TIV, with three-dose schedules of Convidecia/Convidecia/ZF2001 at day 0, day 28 and month 5 (referred to as CV/ZF/ZF (D0-D28-M5)) and CV/ZF/ZF (D0-D56-M6), and two-dose schedules of CV/ZF (D0-M5) and CV/ZF (D0-M6). The primary outcome was the geometric mean titer (GMT) of the neutralizing antibodies against live SARS-CoV-2 virus 14 days after each boost vaccination. The safety outcome was 7-day reactogenicity, measured as solicited local or systemic adverse reactions after each vaccination. Between April 7, 2021, and May 6, 2021, 120 participants were enrolled, among whom 60 were randomly assigned to receive ZF2001 (n=40) or TIV (n=20) at a 28-day interval, and 60 were randomly assigned to receive ZF2001 (n=40) or TIV (n=20) at a 56-day interval. 113 (94.2%) participants received the 2nd injection with ZF2001 4 months after a dose of ZF2001 or TIV. A total of 26 participants (21.7%) reported solicited adverse events within 7 days post boost vaccinations, and all the reported adverse reactions were mild . Among participants receiving ZF001 as second dose, the GMTs of neutralizing antibodies increased to 58.4 IU/ml (42.8-79.8) in 0-28 regimen, and to 80.8 IU/ml (53.1-122.9) in 0-56 regimen at 14 days post first boost dose. The GMTs of neutralizing antibodies increased to 334.9 IU/ml (95% CI 230.4, 486.9) in C/Z/Z (D0-D28-M5) regimen, and 441.2 IU/ml (260.8, 746.4) in C/Z/Z (D0-D56-M6) regimen at 14 days after the third dose. Two-dose schedules of CV/ZF (D0-M5) and CV/ZF (D0-M6) induced comparable antibody level comparable with that elicited by three-dose schedules, with the GMTs of 282.9 IU/ml (142.5, 561.8) and 293.9 IU/ml (137.6, 627.9), respectively. Study limitations include the absence of vaccine effectiveness in real-world, and current lack of immune persistence data and the neutralizing antibodies to Omicron. Conclusions Heterologous boosting with ZF001 following primary vaccination of Convidecia is safe and more immunogenic than a single dose of Convidecia. These results support flexibility in cooperating viral vectored vaccines and recombinant protein vaccine. Trial Registration ClinicalTrial.gov NCT04833101

Dynamic Zero-Covid strategy curtails mutagenesis and emergence of new variants of the SARS-CoV-2 (preprint)

Within the local outbreak period of SARS-CoV-2 Delta variant in Nanjing and Yangzhou, China, we analyzed the mutation process of the Delta variants in 520 cases, as well as the production, spread and elimination of new mutant strains under the non-pharmaceutical interventions (NPI) strategy. The investigation on distribution of COVID-19 cases and phylogenetic analysis of SARS-CoV-2 genome sequences attributed to tracking the transmission chains, transmission chains were terminated by the isolation of the COVID-19 patients and quarantine of close-contracts, suggesting the importance of NPI in prompting some mutations to disappear and stopping the transmission of new variants. Dynamic zero-Covid strategy has been implemented successfully to against the second-largest local epidemic caused by an imported COVID-19 case in China.

Heterologous prime-boost immunization with CoronaVac and Convidecia (preprint)

ABSTRACT Background The safety and immunogenicity of heterologous prime-boost COVID-19 vaccine regimens with one shot of a recombinant adenovirus type-5-vectored COVID-19 vaccine Convidecia has not been reported. Methods We conducted a randomized, controlled, observer-blinded trial of heterologous prime-boost immunization with CoronaVac and Convidecia in healthy adults 18-59 years of age. Eligible participants who were primed with one or two doses of CoronaVac were randomly assigned at a 1:1 ratio to receive a booster dose of Convidecia or CoronaVac. Participants were masked to the vaccine received but not to the three-dose or two-dose regimen. The occurrences of adverse reactions within 28 days after the vaccination were documented. The geometric mean titers of neutralizing antibodies against live SARS-CoV-2 virus were measured at 14 and 28 days after the booster vaccination. Results Between May 25 and 26, 2021, a total of 300 participants were enrolled. Participants who received a booster shot with a heterologous dose of Convidecia reported increased frequencies of solicited injection-site reactions than did those received a homogeneous dose of CoronaVac, but frequencies of systemic reactions. The adverse reactions were generally mild to moderate. The heterologous immunization with Convidecia induced higher live viral neutralizing antibodies than did the homogeneous immunization with CoronaVac (197.4[167.7, 232.4] vs. 33.6[28.3, 39.8] and 54.4[37. 9, 78.0] vs. 12.8[9.3, 17.5]) at day 14 in the three- and two-dose regimen cohort, respectively. Conclusions The heterologous prime-boost regimen with Convidecia after the priming with CoronaVac was safe and significantly immunogenic than a homogeneous boost with CoronaVac ( ClinicalTrials.gov , number NCT04892459 ).

Undergraduate student interest in healthcare career in the context of COVID-19 pandemic (preprint)

ObjectivesThe healthcare profession has been long considered an excellent career choice. Pre-medical experience is documented to be important in shaping future medical landscape. In the wake of the pandemic, there has been intense media spotlight on the healthcare profession and change in academic environment, necessitating analyses of student experience. This project aims to assess change in undergraduate student interest in healthcare career using cross-sectional survey study. MethodsThe project was approved by our Institutional Review Board. Voluntary survey collected data on demographics, socioeconomics, media exposure, academic environment, and change in interest in a healthcare profession. Survey was distributed through the university undergraduate pre-health listserv. Total of 297 responses were obtained. Descriptive statistics including Fishers exact test were applied in the analysis. ResultsMajority of the respondents were Asians (54.9%), second generation immigrants (52.2%), and female (73.4%). Large proportion of the respondents were negatively affected by the pandemic, with losing a job or internship personally (42.1%) or a family member or a friend (62.6%). Students had mixed response to online learning environment, with 27.3% of students noting no change, 40.4% students noting increased difficulty, and 32.3% students noting decreased difficulty of classes. During the pandemic, 47.5% of students noted increased interest in pursuing healthcare career. The change in interest in healthcare career was not associated with xdemographics, economic hardship, or online learning environment. DiscussionDespite the challenges of COVID-19 pandemic, students showed strong interest in pursuing healthcare careers.

First report demonstrating the safety and immunogenicity of the SARS-COV-2 BNT162b1 mRNA vaccine in younger and older Chinese adults: a randomized, placebo-controlled, observer-blind Phase I study (preprint)

An effective vaccine is needed to end the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic. Data from the U.S. NCT04368728 and German EudraCT 2020-001038-36 vaccine trials was recently reported, showing the safety, tolerability, and antibody response of the BNT162b1 vaccine candidate. BNT162b1 encodes the SARS-CoV-2 spike glycoprotein receptor-binding domain and is one of several RNA-based SARS-CoV-2 vaccine candidates under study. Here, we report preliminary results from a Phase I trial testing BNT162b1 in 144 healthy Chinese participants. The safety profile was broadly comparable to that seen in the American and German trials, with fever the only Grade 3 adverse event reported. Prime-boost vaccination with 10 µg or 30 µg BNT162b1 induced robust antibody responses in both younger (18 to 55 years of age) and older (65 to 85) Chinese adults, and interferon-γ T-cell responses to RBD antigen challenge were significantly higher in participants receiving BNT162b1 than those in placebo groups. The 30 µg dose induced increased reactogenicity as well as a more favorable vaccine-elicited virus-neutralizing response than the 10 µg dose in both younger and older Chinese adults. In conclusion, this first report of an mRNA vaccine in an Asian population showed similar results to BNT162b1 trials. This trial was funded by Fosun and BioNTech and registered under ChiCTR2000034825 and NCT04523571.

Safety, Tolerability and Immunogenicity of a Recombinant Adenovirus Type 5 Vectored COVID-19 Vaccine in Healthy Adults in China: Preliminary Report of a First-In Human Single-Center, Open-Label, Dose-Escalating Clinical Trial (preprint)

Background: 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 SARS-Cov-2 strain. This is the first-in-human study of a candidate vaccine against COVID-19.Methods: We conducted a single-center, open-label, dose-escalating clinical trial of Ad5 vectored COVID-19 vaccine. Healthy adults aged between 18-60 years were sequentially enrolled and allocated to receive a single intramuscular injection in one of three dose groups: 5 × 10^10, 1×10^11, and 1·5×10^11 viral particles. Safety was assessed over the next 28 days. Specific antibodies were measured on enzyme-linked immunosorbent assay (ELISA), and the neutralizing antibody responses induced by vaccination were detected by using SARS-CoV-2 virus neutralization and pseudovirus neutralization tests. T-cell responses were accessed by enzyme-linked immunospot (ELISpot) and flow-cytometry assays. Results: A total of 108 participants were recruited and received low dose, middle dose, or high dose vaccine, with 36 in each dose group. 30(83·3%), 30(83·3%), and 27(75·0%) recipients in the low dose, middle dose, and high dose groups reported at least one adverse reaction within the first 7 days after the vaccination. The most common injection-site adverse reaction was pain, the most commonly reported systematic adverse reactions were fever, fatigue, headache, and muscle pain. A majority of the 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. Both ELISA antibodies and neutralizing antibodies increased significantly at day 14, and peaked 28 days post-vaccination. Specific T cell response peaked at day 14 post-vaccination.Conclusions: The Ad5 vectored COVID-19 vaccine is tolerable and immunogenic. Humoral responses against SARS-CoV-2 peaked at day 28 post-vaccination in health adults, and rapid specific T cell responses were noted since day 14.Trial Registration: The study is registered with ClinicalTrials.gov, number NCT04313127. Funding Statement: National Key R&D Program of China (2020YFC10841400), National Science and Technology Major Project (2016ZX10004001, 2018ZX09201005), and CanSino Biotechnology Inc.Declaration of Interests: Mr. Gou report being employees of Tianjin CanSino Biotechnology Inc, No other potential conflict of interest relevant to this article was reported.Ethics Approval Statement: The protocol and informed consent were approved by the Institutional Review Board of the Jiangsu Provincial Center of Disease Control and Prevention. Written informed consents from all participants were obtained before screening. This study was undertaken by Jiangsu Provincial Center of Disease Control and Prevention, Hubei Provincial Center for Disease Control and Prevention and Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology in accordance with the Declaration of Helsinki and Good Clinical Practice.

HTCC as a highly effective polymeric inhibitor of SARS-CoV-2 and MERS-CoV (preprint)

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 healthcare 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 previously developed by us HTCC compound (N-(2-hydroxypropyl)-3-trimethylammonium chitosan chloride), which may be used as potential inhibitor of currently circulating highly pathogenic coronaviruses - SARS-CoV-2 and MERS-CoV.

A data-driven drug repositioning framework discovered a potential therapeutic agent targeting COVID-19 (preprint)

The global spread of SARS-CoV-2 requires an urgent need to find effective therapeutics for the treatment of COVID-19. We developed a data-driven drug repositioning framework, which applies both machine learning and statistical analysis approaches to systematically integrate and mine large-scale knowledge graph, literature and transcriptome data to discover the potential drug candidates against SARS-CoV-2. The retrospective study using the past SARS-CoV and MERS-CoV data demonstrated that our machine learning based method can successfully predict effective drug candidates against a specific coronavirus. Our in silico screening followed by wet-lab validation indicated that a poly-ADP-ribose polymerase 1 (PARP1) inhibitor, CVL218, currently in Phase I clinical trial, may be repurposed to treat COVID-19. Our in vitro assays revealed that CVL218 can exhibit effective inhibitory activity against SARS-CoV-2 replication without obvious cytopathic effect. In addition, we showed that CVL218 is able to suppress the CpG-induced IL-6 production in peripheral blood mononuclear cells, suggesting that it may also have anti-inflammatory effect that is highly relevant to the prevention immunopathology induced by SARS-CoV-2 infection. Further pharmacokinetic and toxicokinetic evaluation in rats and monkeys showed a high concentration of CVL218 in lung and observed no apparent signs of toxicity, indicating the appealing potential of this drug for the treatment of the pneumonia caused by SARS-CoV-2 infection. Moreover, molecular docking simulation suggested that CVL218 may bind to the N-terminal domain of nucleocapsid (N) protein of SARS-CoV-2, providing a possible model to explain its antiviral action. We also proposed several possible mechanisms to explain the antiviral activities of PARP1 inhibitors against SARS-CoV-2, based on the data present in this study and previous evidences reported in the literature. In summary, the PARP1 inhibitor CVL218 discovered by our data-driven drug repositioning framework can serve as a potential therapeutic agent for the treatment of COVID-19.