A Phase I, Prospective, Randomized, Open-labeled Study to Evaluate the Safety, Tolerability, and Immunogenicity of Booster Dose with MVC-COV1901 or MVC-COV1901(Beta) SARS-CoV-2 Vaccine in Adults

BackgroundThe use of variant-based severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine as a booster is being evaluated to overcome reduced neutralisation of variants induced by the original SARS-CoV-2 vaccine and waning protection over time. MethodsThis is a phase one, prospective, randomized, and open-labeled trial to study the safety and immunogenicity of a booster dose consisting of a subunit vaccine based on the stabilized prefusion SARS-CoV-2 spike protein, MVC-COV1901 or its Beta version, MVC-COV1901-Beta. One-hundred and seven participants aged [≥]18 and <55 years, who received two or three prior doses of MVC-COV1901 vaccines, were enrolled and were to receive a booster dose of either 15 mcg of MVC-COV1901, 15 mcg or 25 mcg of MVC-COV1901-Beta in 1:1:1 ratio. The primary endpoints were the incidences of adverse events and immunogenicity of the booster dose from Visit 2 (the day of the booster) to Visit 5 (four weeks after the booster). Cellular immunity was also investigated with memory B cell (MBC) and T cell assays. FindingsAdverse reactions after either MVC-COV1901 or MVC-COV1901-Beta booster doses after two or three doses of MVC-COV1901 were comparable and mostly mild and transient. At four weeks after the booster dose, participants with two prior doses of MVC-COV1901 exhibited numerically higher levels of neutralising antibodies against SARS-CoV-2 or Beta variant than participants with three prior doses of MVC-COV1901 regardless of the type of booster used. However, compared to 15 mcg of MVC-COV1901, 25 mcg of MVC-COV1901-Beta significantly improved neutralising antibody titre against Beta variant and BA.4/BA.5 Omicron variant pseudoviruses. The booster dose also significantly increased the proportion of spike-specific MBCs, including those of Beta and Omicron variants. InterpretationMVC-COV1901-Beta can be effectively used as a booster dose against SARS-CoV-2, including the circulating BA.4/BA.5 Omicron variant. FundingMedigen Vaccine Biologics Corporation

An Evaluation of the Safety and Immunogenicity of MVC-COV1901: Results of an interim analysis of a phase III, parallel group, randomized, double-blind, active-controlled study

BackgroundData from previous studies of the MVC-COV1901 vaccine, a subunit vaccine against SARS-CoV-2 based on the stable prefusion spike protein (S-2P) adjuvanted with CpG 1018 adjuvant and aluminum hydroxide, suggest that the vaccine is generally safe and elicits a good immune response in healthy adults and adolescents. By comparing with AZD1222, this study adds to the findings from previous trials and further evaluates the breadth of protection offered by MVC-COV1901. MethodsIn this phase 3, parallel group, randomized, double-blind, active-controlled trial conducted in 2 sites in Paraguay, we assigned adults aged 18 to 91 years in a 1:1 ratio to receive intramuscular doses of MVC-COV1901 or AZD1222 administered as scheduled in the clinical trial. Serum samples were collected on the day of vaccination and 14 days after the second dose. Primary and secondary safety and immunogenicity endpoints were assessed. In addition, other outcomes investigated were cross-reactive immunity against the Omicron strain and the induction of IgG subclasses. ResultsA total of 1,030 participants underwent randomization. Safety data was derived from this set while primary immunogenicity data involved a per-protocol immunogenicity (PPI) subset including 225 participants. Among the participants, 58% are seropositive at baseline. When compared against AZD1222, MVC-COV1901 exhibited superiority in terms of neutralizing antibody titers and non-inferiority in terms of seroconversion rates. Reactogenicity was generally mild and no serious adverse event was attributable to MVC-COV1901. Both vaccines have a Th1-biased response predominated by the production of IgG1 and IgG3 subclasses. Omicron-neutralizing titers were 44.5 times lower compared to wildtype-neutralizing titers among seronegative individuals at baseline. This fold-reduction was 3.0 times among the seropositive. ConclusionResults presented here demonstrate the safe and robust immunogenicity from MVC-COV1901. Previous infection coupled with vaccination of this vaccine may offer protection against the Omicron strain though its durability is still unknown. ClinicalTrials.gov registrationNCT05011526

Safety and immunogenicity of SARS-CoV-2 vaccine MVC-COV1901 in adolescents in Taiwan: A double-blind, randomized, placebo-controlled phase 2 trial

BackgroundMVC-COV1901 is a subunit SARS-CoV-2 vaccine based on the prefusion spike protein S-2P and adjuvanted with CpG 1018 and aluminum hydroxide. Although MVC-COV1901 has been licensed for emergency use for adults in Taiwan, the safety and immunogenicity of MVC-COV1901 in adolescents remained unknown. As young people play an important role in SARS-CoV-2 transmission and epidemiology, a vaccine approved for adolescents and eventually, children, will be important in mitigating the COVID-19 pandemic. MethodsThis study is a prospective, double-blind, multi-center phase 2 trial evaluating the safety, tolerability and immunogenicity of two doses of the SARS-CoV-2 vaccine MVC-COV1901 in adolescents. Healthy adolescents from age of 12 to 17 years were recruited and randomly assigned (6:1) to receive two intramuscular doses of either MVC-COV1901 or placebo at 28 days apart. The primary outcomes were safety and immunogenicity from the day of first vaccination (Day 1) to 28 days after the second vaccination (Day 57), and immunogenicity of MVC COV1901 in adolescents as compared to young adult vaccinees in terms of neutralizing antibody titers and seroconversion rate. The secondary outcomes were safety and immunogenicity of MVC-COV1901 as compared to placebo in adolescents in terms of immunoglobulin titers and neutralizing antibody titers over the study period. ResultsBetween July 21, 2021 and December 22, 2021, a total of 399 adolescent participants were included for safety evaluation after enrollment to receive at least one dose of either MVC-COV1901 (N=341) or placebo (N=58). Of these, 334 and 46 participants went on to receive two doses of either MVC-COV1901 or placebo, respectively, and were included in the per protocol set (PPS) for immunogenicity analysis. Adverse events were mostly mild and were similar in MVC-COV1901 and placebo groups. The most commonly reported adverse events were pain/tenderness and malaise/fatigue. All immunogenicity endpoints in the adolescent group were non-inferior to the endpoints seen in the young adult and placebo groups. ConclusionsThe safety and immunogenicity data presented here showed that MVC-COV1901 has similar safety profile and non-inferior immunogenicity in adolescents compared to young adults. ClinicalTrials.gov registrationNCT04951388.

Intranasal Nanoemulsion Adjuvanted S-2P Vaccine Demonstrates Protection in Hamsters and Induces Systemic, Cell-Mediated and Mucosal Immunity in Mice

With the rapid progress made in the development of vaccines to fight the SARS-CoV-2 pandemic, almost >90% of vaccine candidates under development and a 100% of the licensed vaccines are delivered intramuscularly (IM). While these vaccines are highly efficacious against COVID-19 disease, their efficacy against SARS-CoV-2 infection of upper respiratory tract and transmission is at best temporary. Development of safe and efficacious vaccines that are able to induce robust mucosal and systemic immune responses are needed to control new variants. In this study, we have used our nanoemulsion adjuvant (NE01) to intranasally (IN) deliver stabilized spike protein (S-2P) to induce immunogenicity in mouse and hamster models. Data presented demonstrate the induction of robust immunity in mice resulting in 100% seroconversion and protection against SARS-CoV-2 in a hamster challenge model. There was a significant induction of mucosal immune responses as demonstrated by IgA- and IgG-producing memory B cells in the lungs of animals that received intranasal immunizations compared to an alum adjuvanted intramuscular vaccine. The efficacy of the S-2P/NE01 vaccine was also demonstrated in an intranasal hamster challenge model with SARS-CoV-2 and conferred significant protection against weight loss, lung pathology, and viral clearance from both upper and lower respiratory tract. Our findings demonstrate that intranasal NE01-adjuvanted vaccine promotes protective immunity against SARS-CoV-2 infection and disease through activation of three arms of immune system: humoral, cellular, and mucosal, suggesting that an intranasal SARS-CoV-2 vaccine may play a role in addressing a unique public health problem and unmet medical need.

Protection of Hamsters Challenged with SARS-CoV-2 after Two Doses of MVC-COV1901 Vaccine Followed by a Single Intranasal Booster with Nanoemulsion Adjuvanted S-2P Vaccine

Intramuscular vaccines have greatly reduced hospitalization and death due to severe COVID-19. However, most countries are experiencing a resurgence of infection driven predominantly by the Delta and Omicron variants of SARS-CoV-2. In response, booster dosing of COVID-19 vaccines has been implemented in many countries to address waning immunity and reduced protection against the variants. However, intramuscular boosting fails to elicit mucosal immunity and therefore does not solve the problem of persistent viral carriage and transmission, even in patients protected from severe disease. In this study, two doses of stabilized prefusion SARS-CoV-2 spike (S-2P)-based intramuscular vaccine adjuvanted with Alum/CpG1018, MVC-COV1901, were used as a primary vaccination series, followed by an intranasal booster vaccination with nanoemulsion (NE01)-adjuvanted S-2P vaccine in a hamster model to demonstrate immunogenicity and protection from viral challenge. Here we report that this vaccination regimen resulted not only in the induction of robust immunity and protection against weight loss and lung pathology following challenge with SARS-CoV-2, but also led to increased viral clearance from both upper and lower respiratory tracts. Our findings showed that intramuscular MVC-COV1901 vaccine followed by a booster with intranasal NE01-adjuvanted vaccine promotes protective immunity against both viral infection and disease, suggesting that this immunization protocol may offer a solution in addressing a significant, unmet medical need for both the COVID-19 and future pandemics.

Optimization of a Thermal Flow Meter for Failure Management of the Shunt in Pediatric Hydrocephalus Patients.

Hydrocephalus patients suffer from an abnormal buildup of cerebrospinal fluid (CSF) in their ventricles, and there is currently no known way to cure hydrocephalus. The most prevalent treatment for managing hydrocephalus is to implant a ventriculoperitoneal shunt, which diverts excess CSF out of the brain. However, shunts are prone to failure, resulting in vague symptoms. Our patient survey results found that the lack of specificity of symptoms complicates the management of hydrocephalus in the pediatric population. The consequences include persistent mental burden on caretakers and a significant amount of unnecessary utilization of emergency healthcare resources due to the false-positive judgement of shunt failure. In order to reliably monitor shunt failures for hydrocephalus patients and their caretakers, we propose an optimized design of the thermal flow meter for precise measurements of the CSF flow rate in the shunt. The design is an implantable device which slides onto the shunt and utilizes sinusoidal heating and temperature measurements to improve the signal-to-noise ratio of flow-rate measurements by orders of magnitude.Clinical Relevance- An implantable flow meter would be transformative to allow hydrocephalus patients to monitor their shunt function at home, resulting in reduced hospital visits, reduced exposure to radiation typically required to rule out shunt failure, and reduced caretaker anxiety.

The age-dependent immunogenicity after two doses of MVC-COV1901 vaccine.

A post-hoc analysis of the phase 2 data was performed for the SARS-COV-2 subunit protein vaccine MVC-COV1901. Anti-spike IgG, neutralization assays with live virus and pseudovirus were used to demonstrate age-dependent vaccine-induced antibody response to the vaccine. Results showed that an association exists between age and immune responses to the vaccine, providing further support for the need of booster shots, especially for the older age groups.

Protection of Hamsters Challenged with SARS-CoV-2 Variants of Concern by Two Doses of MVC-COV1901 Vaccine Followed by a Single Dose of Beta Variant Version of MVC-COV1901

The current fight against COVID-19 is compounded by the Variants of Concern (VoCs), which can diminish the effectiveness of vaccines and potentially increase viral transmission and severity of disease. MVC-COV1901 is a protein subunit vaccine based on the prefusion SARS-CoV-2 spike protein (S-2P) and is adjuvanted with CpG 1018 and aluminum hydroxide. In this study, we used the Delta variant to challenge hamsters inoculated with S-2P from the Wuhan wildtype and the Beta variant in two-dose or three-dose regimens. Two doses of wildtype S-2P followed by the third dose of Beta variant was shown to induce the highest neutralizing antibody titer against live SARS-CoV-2 of the wildtype and all current VoCs, as well as improved neutralization against Omicron variant pseudovirus compared to three doses of wildtype S-P. All regimens of vaccination were able to protect hamsters from SARS-CoV-2 Delta variant challenge and resulted in reduced lung live virus titer and pathology. Three doses of vaccination also significantly reduced lung viral RNA titer, regardless of whether the wildtype or Beta variant S-2P was used as the third dose. Based on the immunogenicity and viral challenge data, two doses of wildtype S-2P followed by the third dose of Beta variant S-2P induced potent antibody immune responses against the VoCs.

Safety and Immunogenicity of CpG 1018 and Aluminium Hydroxide-Adjuvanted SARS-CoV-2 S-2P Protein Vaccine MVC-COV1901: A Large-Scale Double-Blinded, Randomised, Placebo-Controlled Phase 2 Trial

BackgroundWe have assessed the safety and immunogenicity of the COVID-19 vaccine MVC-COV1901, a recombinant protein vaccine containing prefusion-stabilized spike protein S-2P adjuvanted with CpG 1018 and aluminium hydroxide. MethodsThis is a phase 2, prospective, randomised, double-blind, placebo-controlled, and multi-centre study to evaluate the safety, tolerability, and immunogenicity of the SARS-CoV-2 vaccine candidate MVC-COV1901. The study comprised 3,844 participants of [≥] 20 years who were generally healthy or with stable pre-existing medical conditions. The study participants were randomly assigned in a 6:1 ratio to receive either MVC-COV1901 containing 15 g of S-2P protein or placebo containing saline. Participants received two doses of MVC-COV1901 or placebo, administered 28 days apart via intramuscular injection. The primary outcomes were to evaluate the safety, tolerability, and immunogenicity of MVC-COV1901 from Day 1 (the day of first vaccination) to Day 57 (28 days after the second dose). Immunogenicity of MVC-COV1901 was assessed through geometric mean titres (GMT) and seroconversion rates (SCR) of neutralising antibody and antigen-specific immunoglobulin. This clinical trial is registered at ClinicalTrials.gov: NCT04695652. FindingsFrom the start of this phase 2 trial to the time of interim analysis, no vaccine-related Serious Adverse Events (SAEs) were recorded. The most common solicited adverse events across all study participants were pain at the injection site (64%), and malaise/fatigue (35%). Fever was rarely reported (<1%). For all participants in the MVC-COV1901 group, at 28 days after the second dose against wild type SARS-CoV-2 virus, the GMT was 662{middle dot}3 (408 IU/mL), the GMT ratio was 163{middle dot}2, and the seroconversion rate was 99{middle dot}8%. InterpretationMVC-COV1901 shows good safety profiles and promising immunogenicity responses. The current data supports MVC-COV1901 to enter phase 3 efficacy trials and could enable regulatory considerations for Emergency Use Authorisation (EUA). FundingMedigen Vaccine Biologics Corporation and Taiwan Centres for Disease Control.

First-in-Human Trial of a Recombinant Stabilized Prefusion SARS-CoV-2 Spike Protein Vaccine with Adjuvant of Aluminum Hydroxide and CpG 1018

DesignThis is a phase 1, dose-escalation open-label trial to evaluate the safety and immunogenicity of MVC-COV1901, a recombinant stabilized prefusion SARS-CoV-2 spike (S-2P) protein vaccine with adjuvant of aluminum hydroxide and CpG 1018. MethodsWe enrolled 45 healthy adults from 20 to 49 years of age to be administered with two vaccinations of MVC-COV1901 in a low dose (LD), middle dose (MD), and high dose (HD) of spike protein at 28 days apart. There were 15 participants in each dose group, and all of them were followed up for 28 days after the second vaccination at the time of interim analysis. Adverse events (AEs) and laboratory data were recorded for safety evaluation. Blood samples were collected for wild-type SARS-CoV-2 and pseudovirus neutralization assays as well as SARS-CoV-2 spike-specific immunoglobulin G (IgG) at various times. Overall, the study duration will be 7 months. ResultsSolicited events were mostly mild and similar in the participants of all three dose groups. No subject experienced fever. There were no serious nor adverse events of special interest at the time point of this interim report. After the second vaccination, the SARS-CoV-2 spike specific IgG titers increased with peak geometric mean titers at 7178.245 (LD), 7746.086 (MD), and 11220.58 (HD), respectively. Serum neutralizing activity was detected by two methods in all participants of MD and HD groups, with geometric mean values generally comparable to those of a panel of control convalescent serum specimens. All of the participants in the MD and HD groups were seroconverted after the second vaccination. ConclusionsThe MVC-COV1901 vaccine is safe and elicits remarkable immune responses especially in the MD and HD groups. Trial RegistrationClinicalTrials.gov NCT 04487210

Evaluating the neutralizing ability of a CpG-adjuvanted S-2P subunit vaccine against SARS-CoV-2 Variants of Concern

Vaccination is currently the best weapon to control the COVID-19 pandemic. However, an alarming number of novel variants termed Variants of Concern (VoC) were found to harbor mutations that diminished the neutralizing capacity of antibodies elicited by the vaccines. We have investigated the neutralizing titers of antibodies from sera of humans and rats immunized with the MVC-COV1901 vaccine against pseudoviruses coated with the wildtype, D614G, B.1.1.7, or B.1.351 spike proteins. Rats vaccinated with two doses of adjuvanted S-2P retained neutralization activities against the B.1.351 variant, albeit with a slight reduction compared to wildtype. Phase 1 vaccinated subjects showed more reduced neutralization abilities against the B.1.351 variant. The study is among the first, to our knowledge, to demonstrate dose-dependent neutralizing responses against VoCs, particularly against B.1.351, from different doses of antigen in a clinical trial for a subunit protein COVID-19 vaccine. The appearance of vaccine escape variants is a growing concern facing many current COVID-19 vaccines and therapeutics. Strategies should be adopted against the ever-changing nature of these variants. The observations of this study grant us valuable insight into preemptive strikes against current and future variants.

CpG-adjuvanted stable prefusion SARS-CoV-2 spike protein protected hamsters from SARS-CoV-2 challenge

The COVID-19 pandemic presents an unprecedented challenge to global public health. Rapid development and deployment of safe and effective vaccines are imperative to control the pandemic. In the current study, we applied our adjuvanted stable prefusion SARS-CoV-2 spike (S-2P)-based vaccine, MVC-COV1901, to hamster models to demonstrate immunogenicity and protection from virus challenge. Golden Syrian hamsters immunized intramuscularly with two injections of 1 {micro}g or 5 {micro}g of S-2P adjuvanted with CpG 1018 and aluminum hydroxide (alum) were challenged intranasally with SARS-CoV-2. Prior to virus challenge, the vaccine induced high levels of neutralizing antibodies with 10,000-fold higher IgG level and an average of 50-fold higher pseudovirus neutralizing titers in either dose groups than vehicle or adjuvant control groups. Six days after infection, vaccinated hamsters did not display any weight loss associated with infection and had significantly reduced lung pathology and most importantly, lung viral load levels were reduced to lower than detection limit compared to unvaccinated animals. Vaccination with either 1 g or 5 g of adjuvanted S-2P produced comparable immunogenicity and protection from infection. This study builds upon our previous results to support the clinical development of MVC-COV1901 as a safe, highly immunogenic, and protective COVID-19 vaccine.

Development of CpG-adjuvanted stable prefusion SARS-CoV-2 spike antigen as a subunit vaccine against COVID-19

The COVID-19 pandemic caused by the novel coronavirus SARS-CoV-2 is a worldwide health emergency. The immense damage done to public health and economies has prompted a global race for cures and vaccines. In developing a COVID-19 vaccine, we applied technology previously used for MERS-CoV to produce a prefusion-stabilized SARS-CoV-2 spike protein by adding two proline substitutions at the top of the central helix (S-2P). To enhance immunogenicity and mitigate the potential vaccine-induced immunopathology, CpG 1018, a Th1-biasing synthetic toll-like receptor 9 (TLR9) agonist was selected as an adjuvant candidate. S-2P was combined with various adjuvants, including CpG 1018, and administered to mice to test its effectiveness in eliciting anti-SARS-CoV-2 neutralizing antibodies. S-2P in combination with CpG 1018 and aluminum hydroxide (alum) was found to be the most potent immunogen and induced high titer of spike-specific antibodies in sera of immunized mice. The neutralizing abilities in pseudotyped lentivirus reporter or live wild-type SARS-CoV-2 were measured with reciprocal inhibiting dilution (ID50) titers of 5120 and 2560, respectively. In addition, the antibodies elicited were able to cross-neutralize pseudovirus containing the spike protein of the D614G variant, indicating the potential for broad spectrum protection. A marked Th-1 dominant response was noted from cytokines secreted by splenocytes of mice immunized with CpG 1018 and alum. No vaccine-related serious adverse effects were found in the dose-ranging study in rats administered single- or two-dose regimens with up to 50 g of S-2P combined with CpG 1018 alone or CpG 1018 with alum. These data support continued development of CHO-derived S-2P formulated with CpG 1018/alum as a candidate vaccine to prevent COVID-19 disease.

Effects of cetirizine in dogs with chronic atopic dermatitis: a randomized, double blind, placebo-controlled trial

This study was conducted to evaluate the effects of cetirizine in dogs with atopic dermatitis (AD) while fulfilling Favrot's diagnostic clinical criteria. Dogs received either 3 mg/kg cetirizine (n = 27), or a placebo (n = 23) orally once daily for 14 days in a randomized, double blind, placebo-controlled study, without concomitant medication. The effects were evaluated using a pruritus visual analog scale at the start (day 0) and at day 14. After 14 days, cetirizine clearly had no effect on the pruritus in dogs with chronic AD, and there was no significant difference between groups. These findings indicated that cetirizine (and likely H1 histamine receptor antagonists in general) should not be recommended for the control of pruritus in dogs with long term allergies.

Active immunity induced by passive IgG post-exposure protection against ricin.

Therapeutic antibodies can confer an instant protection against biothreat agents when administered. In this study, intact IgG and F(ab')2 from goat anti-ricin hyperimmune sera were compared for the protection against lethal ricin mediated intoxication. Similar ricin-binding affinities and neutralizing activities in vitro were observed between IgG and F(ab')2 when compared at the same molar concentration. In a murine ricin intoxication model, both IgG and F(ab')2 could rescue 100% of the mice by one dose (3 nmol) administration of antibodies 1 hour after 5 × LD50 ricin challenge. Nine days later, when the rescued mice received a second ricin challenge (5 × LD50), only the IgG-treated mice survived; the F(ab')2-treated mice did not. The experimental design excluded the possibility of residual goat IgG responsible for the protection against the second ricin challenge. Results confirmed that the active immunity against ricin in mice was induced quickly following the passive delivery of a single dose of goat IgG post-exposure. Furthermore, it was demonstrated that the induced active immunity against ricin in mice lasted at least 5 months. Therefore, passive IgG therapy not only provides immediate protection to the victim after ricin exposure, but also elicits an active immunity against ricin that subsequently results in long term protection.

Conformation-dependent high-affinity potent ricin-neutralizing monoclonal antibodies.

Ricin is a potential biothreat agent with no approved antidote available for ricin poisoning. The aim of this study was to develop potent antibody-based antiricin antidotes. Four strong ricin resistant hybridoma clones secreting antiricin monoclonal antibodies (mAbs) were developed. All four mAbs are bound to conformational epitopes of ricin toxin B (RTB) with high affinity (KD values from 2.55 to 36.27 nM). RTB not only triggers cellular uptake of ricin, but also facilitates transport of the ricin toxin A (RTA) from the endoplasmic reticulum to the cytosol, where RTA exerts its toxic activity. The four mAbs were found to have potent ricin-neutralizing capacities and synergistic effects among them as determined by an in vitro neutralization assay. In vivo protection assay demonstrated that all four mAbs had strong efficacy against ricin challenges. D9 was found to be exceptionally effective. Intraperitoneal (i.p.) administration of D9, at a dose of 5 µ g, 6 weeks before or 6 hours after an i.p. challenge with 5 × LD50 of ricin was able to protect or rescue 100% of the mice, indicating that mAb D9 is an excellent candidate to be developed as a potent antidote against ricin poisoning for both prophylactic and therapeutic purposes.