Immunogenicity and safety of heterologous mRNA-1273/MVC-COV1901 vaccination versus homologous mRNA1273 vaccination: A randomized, double-blind controlled study.

BACKGROUND/PURPOSE: MVC-COV1901 is a protein vaccine based on the same SARS-CoV-2 strain used in mRNA vaccine mRNA-1273. Data are lacking on immunogenicity and safety of MVC-COV1901 as heterologous boost for people already received one dose of mRNA-1273. METHODS: This is a randomized, double-blind trial that recruited adults aged 20-70 years who previously received a single dose of mRNA-1273 vaccine and were randomly assigned in a 1:1 ratio to receive a second dose with the homologous vaccine or protein-based MVC-COV1901 8-12 weeks after the first dose. The primary outcome was neutralizing antibody titers in terms of the geometric mean titer (GMT) 14 days after the second dose. Safety was assessed in all participants who received a dose of the study vaccine. The study is registered with ClinicalTrials.gov (NCT05079633). RESULTS: From September 30 to November 5, 2021, 144 participants were enrolled and randomly assigned to the MVC-COV1901 boost group (n = 72) or the mRNA-1273 boost group (n = 72). The neutralizing antibodies on Day 15 and the anti-SARS-CoV-2 IgG titers on Day 15 and 29 of homologous mRNA-1273 were significantly higher than those of heterologous mRNA-1273/MVC-COV1901. Cellular immune responses were comparable in both groups. However, adverse events were much more frequent after the mRNA-1273 boost than after the MVC-COV1901 boost. CONCLUSION: Our results show that heterologous boost with MVC-COV1901 yielded an inferior immunogenicity but significantly fewer adverse events, compared with homologous boost with mRNA-1273. In people experienced severe adverse events after prime dose of mRNA-1273, as well as in periods when the supply of mRNA-1273 is limited, MVC-COV1901 could serve as an acceptable alternative heterologous boost.

Achievements of COVID-19 Vaccination Programs: Taiwanese Perspective

The coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a global health crisis. The specific characteristics of aerosol transmission in the latent period and the contagiousness of SARS-CoV-2 lead to rapid spread of infection in the community. Vaccination is the most effective method for preventing infection and severe outcomes. As of December 1, 2022, 88% of the Taiwanese population had received at least two doses of COVID-19 vaccines. Heterologous vaccination with ChAdOx1–mRNA-based or ChAdOx1–protein-based vaccines has been found to elicit higher immunogenicity than homologous vaccination with ChAdOx1–ChAdOx1 vaccines. A longitudinal cohort study revealed that 8–12-week intervals between the two heterologous vaccine doses of the primary series led to good immunogenicity and that the vaccines were safe. A third booster dose of mRNA vaccine is being encouraged to evoke effective immune responses against variants of concern. A novel domestic recombinant protein subunit vaccine (MVC-COV1901) was manufactured and authorized for emergency use in Taiwan. It has shown a good safety profile, with promising neutralizing antibody titers against SARS-CoV-2. Given the global pandemic due to emerging novel variants of SARS-CoV-2, booster COVID-19 vaccines and appropriate intervals between booster doses need to be investigated.

Safety and immunogenicity of homologous versus heterologous booster dose with AZD1222, mRNA-1273, or MVC-COV1901 SARS-CoV-2 vaccines in adults: An observer-blinded, multi-center, phase 2 randomized trial.

OBJECTIVES: To report the safety and immunogenicity profile of a protein subunit vaccine (MVC-COV1901) compared to AZD1222 and mRNA-1273 when given as a third (booster) dose to individuals who have completed different primary vaccine regimens. METHODS: Individuals were classified according to their primary vaccine regimens, including two-dose MVC-COV1901, AZD1222, or mRNA-1273. A third dose of either half-dose MVC-COV1901, full-dose MVC-COV1901, standard-dose AZD1222, half-dose mRNA-1273 was administered in a 1:1:1:1 treatment ratio to individuals with an interval range of 84-365 days after the second dose. Endpoints included safety, humoral immunogenicity, and cell-mediated immune response on trial days 15 and 29. Exploratory endpoint included testing against variants of concern (Omicron). RESULTS: Overall, 803 participants were randomized and boosted - 201 received half-dose MVC-COV1901, 196 received full-dose MVC-COV1901, 203 received AZD1222, and 203 received half-dose mRNA-1273. Reactogenicity was mild to moderate, and less in the MVC-COV1901 booster group. Heterologous boosting provided the best immunogenic response. Boosting with mRNA-1273 in MVC-COV1901 primed individuals induced the highest antibody titers, even against Omicron, and cell-mediated immune response. CONCLUSIONS: Overall, MVC-COV1901 as a booster showed the best safety profiles. MVC-COV1901 as a primary series, with either homologous or heterologous booster, elicited the highest immunogenic response. CLINICALTRIALS: gov registration NCT05197153.

A Retrospective Study of the Safety and Immunogenicity of MVC-COV1901 Vaccine for People Living with HIV.

BACKGROUND: This study aimed to assess the safety and immunogenicity of MVC-COV1901, a recombinant COVID-19 protein vaccine, containing S-2P protein adjuvanted with CpG 1018 and aluminum hydroxide, for people living with HIV (PWH). METHODS: A total of 57 PWH of ≥20 years of age who are on stable antiretroviral therapy were compared with 882 HIV-negative participants. Participants received two doses of MVC-COV1901 28 days apart. RESULTS: No vaccine-related serious adverse events (SAEs) were recorded. Seroconversion rates (SCRs) of 100% and 99.8% were achieved in PWH and comparators, respectively, 28 days after the second dose. After adjusting for sex, age, BMI category, and comorbidity, the adjusted GMT ratio of comparator/PWH was 3.2 (95% CI 2.5-4). A higher CD4/CD8 ratio was associated with a higher GMT (R = 0.27, p = 0.039). MVC-COV1901 has shown robust safety but elicited weaker immune responses in PWH. CONCLUSIONS: Further investigations may be needed to determine whether PWH require distinct immunization strategies with improved immunogenicity. The main study is registered at ClinicalTrials.gov (NCT04695652).

Evolution of anti-SARS-CoV-2 spike protein titers after two-dose of COVID-19 vaccination among people living with HIV.

Background: A community COVID-19 outbreak caused by the B.1.1.7 SARS-CoV-2 variant occurred in Taiwan in May 2021. High-risk populations such as people living with HIV (PLWH) were recommended to receive two doses of COVID-19 vaccines. While SARS-CoV-2 vaccines have demonstrated promising results in general population, real-world information on the serological responses remains limited among PLWH. Methods: PLWH receiving the first dose of SARS-CoV-2 vaccine from 2020 to 2021 were enrolled. Determinations of anti-SARS-CoV-2 spike IgG titers were performed every one to three months, the third dose of the SARS-CoV-2 vaccine or confirmed SARS-CoV-2 infection. All serum samples were tested for anti-nucleocapsid antibody and those tested positive were excluded from analysis. Results: A total of 1189 PLWH were enrolled: 829 (69.7%) receiving two doses of the AZD1222 vaccine, 232 (19.5%) of the mRNA-1273 vaccine, and 128 (10.8%) of the BNT162b2 vaccine. At all time-points, PLWH receiving two doses of mRNA vaccines had consistently higher antibody levels than those receiving the AZD1222 vaccine (p <0.001 for all time-point comparisons). Factors associated with failure to achieve an anti-spike IgG titer >141 BAU/mL within 12 weeks, included type 2 diabetes mellitus (DM) (adjusted odds ratio [aOR], 2.24; 95% CI, 1.25-4), a CD4 T cell count <200 cells/mm3 upon receipt of the first dose of vaccination (aOR, 3.43; 95% CI, 1.31-9) and two homologous AZD1222 vaccinations (aOR, 16.85; 95%CI, 10.13-28). For those receiving two doses of mRNA vaccines, factors associated with failure to achieve an anti-spike IgG titer >899 BAU/mL within 12 weeks were a CD4 T cell count <200 cells/mm3 on first-dose vaccination (aOR, 3.95; 95% CI, 1.08-14.42) and dual BNT162b2 vaccination (aOR, 4.21; 95% CI, 2.57-6.89). Conclusions: Two doses of homologous mRNA vaccination achieved significantly higher serological responses than vaccination with AZD1222 among PLWH. Those with CD4 T cell counts <200 cells/mm3 and DM had consistently lower serological responses.

Impact of coronavirus disease on the HIV testing and health care delivery at a university hospital in Taiwan, 2020-2021

Background To contain the coronavirus disease 2019 (Covid-19) pandemic, non-pharmacologic interventions, including lockdown and social distancing, may have adverse impact on access to HIV testing and care. This study investigated the impact of Covid-19 on HIV testing and care at a major hospital in Taiwan in 2020-2021. Methods The numbers of clients seeking anonymous HIV voluntary counseling and testing were compared 2 years before (2018-2019) and 2 years after Covid-19 outbreak (2020-2021). People living with HIV (PLWH) who sought care at the hospital during 2018-2021 were included to examine the status of HIV care delivery and disposition. Results The annual number of HIV screening tests performed had significantly decreased from 2,507 and 2,794 in 2018 and 2019, respectively, to 2,161 and 1,737 in 2020 and 2021, respectively. The rate of discontinuation of HIV care among PLWH was 3.7% in 2019, which remained unchanged in 2020 (3.7%) and 2021 (3.8%). The respective percentage of annual plasma HIV RNA testing <2 times increased from 8.4% and 7.8% in 2018 and 2019 to 7.0% and 10.7% in 2020 and 2021, so was that of annual syphilis testing <2 times (10.1% and 8.8% to 7.9% and 12.0%). The rates of plasma HIV RNA <200 copies/ml ranged from 97.0% to 98.1% in 2018-2021. Conclusions During the Covid-19 pandemic, access to HIV counseling and testing was significantly limited. While the number of HIV-related testing decreased, the impact of Covid-19 on the continuity of antiretroviral therapy and viral suppression among PLWH appeared to be minimal in Taiwan.

Safety and immunogenicity of MVC-COV1901 vaccine in older adults: Phase 2 randomized dose-comparison trial.

INTRODUCTION: Older adults are subject to higher COVID-19 infection and mortality rates. Safety and immunogenicity of MVC-COV1901, a protein subunit vaccine have been demonstrated in phase 2 clinical trial for the general population, and negative correlations have been observed between immune responses and age, however, older adults were under-represented. METHODS: A double-blind, randomized, multi-center study compared safety and immunogenicity of high-dose (25 mcg) to mid-dose (15 mcg) of MVC-COV1901 administered 2 times 28 days apart in 420 participants of 65 years and older. The results have been stratified by the comorbidity status. RESULTS: Both high and mid-dose regimens elicited mostly mild adverse events and robust immune responses when measured as neutralizing and binding antibodies titers. High doses elicited better immune responses in the group without comorbidities. CONCLUSION: Given the general population-associated safety and immunogenicity of MVC-COV1901, we recommend high dose for immunization of elder adults with MVC-COV1901. The clinical trial was registered at https://clinicaltrials.gov/ (NCT04822025).

Hepatitis C microelimination among people living with HIV in Taiwan.

To reach the WHO target of hepatitis C virus (HCV) elimination by 2025, Taiwan started to implement free-of-charge direct-acting antiviral (DAA) treatment programme in 2017. Evaluating the progress of HCV microelimination among people living with HIV (PLWH) is a critical step to identify the barriers to HCV elimination. PLWH seeking care at a major hospital designated for HIV care in Taiwan between January 2011 and December 2021 were retrospectively included. For PLWH with HCV-seropositive or HCV seroconversion during the study period, serial HCV RNA testing was performed using archived samples to confirm the presence of HCV viremia and estimate the prevalence and incidence of HCV viremia. Overall, 4199 PLWH contributed to a total of 27,258.75 person-years of follow-up (PYFU). With the reimbursement of DAAs and improvement of access to treatments, the prevalence of HCV viremia has declined from its peak of 6.21% (95% CI, 5.39-7.12%) in 2018 to 2.09% (95% CI, 1.60-2.77%) in 2021 (decline by 66.4% [95% CI, 55.4-74.7%]); the incidence has declined from 25.94 per 1000 PYFU (95% CI, 20.44-32.47) in 2019 to 12.15% per 1000 PYFU (95% CI, 8.14-17.44) (decline by 53.2% [95% CI, 27.3-70.6%]). However, the proportion of HCV reinfections continued to increase and accounted for 82.8% of incident HCV infections in 2021. We observed significant declines of HCV viremia among PLWH with the expansion of the DAA treatment programme in Taiwan. Further improvement of the access to DAA retreatments is warranted to achieve the goal of HCV microelimination.

Durability and Immunogenicity of Neutralizing Antibodies Response Against Omicron Variants After Three Doses of Subunit SARS-CoV-2 Vaccine MVC-COV1901: An Extension to an Open-Label, Dose-Escalation Phase 1 Study.

INTRODUCTION: MVC-COV1901 is a protein subunit COVID-19 vaccine based on the stable prefusion spike protein S-2P adjuvanted with CpG 1018 and aluminum hydroxide. Interim results of a phase 2 clinical trial demonstrated favorable safety profile and immunogenicity and the vaccine has been authorized for use in Taiwan. However, waning antibody levels after immunization and variants of concern (VoC) could negatively impact vaccine-induced neutralization of virus. In this extension to the phase 1 clinical study we investigated a three-dose regimen of MVC-COV1901 for durability of antibody levels and virus neutralization capacity, including neutralization of the Omicron variant. METHODS: Forty-five healthy adults from 20 to 49 years of age were divided into three groups of 15 participants receiving two doses of either low dose (LD), medium dose (MD), or high dose (HD) of MVC-COV1901. Six months after the second dose (day 209), a third MD dose of MVC-COV1901 was administered to the LD and MD groups and a HD dose was given to the HD group. Safety was followed for up to 28 days after the booster dose by monitoring incidences of adverse events (AE). Immunogenicity and antibody persistence for up to 6 months after the booster dose were assessed by neutralizing assay with the wild-type (Wuhan) SARS-CoV-2 virus. To examine the immunogenicity of booster dose against variants, neutralizing assays were carried out with the Alpha, Beta, and Delta variant viruses and the Omicron variant pseudovirus using samples from 4 weeks after the booster dose. RESULTS: Adverse reactions after the booster dose were mostly mild and comparable to that of the first two doses. Compared to day 209, neutralizing antibodies were increased by 10.3-28.9 times at 4 weeks after the booster. During the 6-month follow-up after the booster, the rate of decline of neutralizing antibody level was much less than that after the second dose. Three doses of MVC-COV1901 also improved antibody-mediated neutralization of Alpha, Beta, and Delta variants as well as the Omicron variant pseudovirus. CONCLUSION: Our data showed increased persistence of neutralizing antibodies and enhancement of immunogenicity against VoCs offered after a third dose of MVC-COV1901. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT04487210.

Effectiveness of COVID-19 vaccination among people living with HIV during a COVID-19 outbreak.

COVID-19 vaccination is recommended for at-risk populations, but the vaccine effectiveness in people living with HIV (PLWH) remains incompletely understood. Here we demonstrate that COVID-19 vaccination was clinically effective among PLWH during the outbreak setting with a low endemicity of COVID-19 where non-pharmaceutical interventions were strictly implemented.

Safety and immunogenicity of CpG 1018 and aluminium hydroxide-adjuvanted SARS-CoV-2 S-2P protein vaccine MVC-COV1901: interim results of a large-scale, double-blind, randomised, placebo-controlled phase 2 trial in Taiwan.

BACKGROUND: MVC-COV1901, a recombinant protein vaccine containing pre-fusion-stabilised spike protein S-2P adjuvanted with CpG 1018 and aluminium hydroxide, has been shown to be well tolerated with a good safety profile in healthy adults aged 20-49 years in a phase 1 trial, and provided a good cellular and humoral immune responses. We present the interim safety, tolerability, and immunogenicity results of a phase 2 clinical trial of the MVC-COV1901 vaccine in Taiwan. METHODS: This is a large-scale, double-blind, randomised, placebo-controlled phase 2 trial done at ten medical centres and one regional hospital in Taiwan. Individuals aged 20 years or older who were generally healthy or had stable pre-existing medical conditions were eligible for enrolment. Exclusion criteria included (but were not limited to) travel overseas within 14 days of screening, intention to travel overseas within 6 months of the screening visit, and the absence of prespecified medical conditions, including immunosuppressive illness, a history of autoimmune disease, malignancy with risk to recur, a bleeding disorder, uncontrolled HIV infection, uncontrolled hepatitis B and C virus infections, SARS-CoV-1 or SARS-CoV-2 infections, an allergy to any vaccine, or a serious medical condition that could interfere with the study. Study participants were randomly assigned (6:1) to receive two doses of either MVC-COV1901 or placebo, administered via intramuscular injection on day 1 and day 29. MVC-COV1901 contained 15 µg of S-2P protein adjuvanted with 750 µg CpG 1018 and 375 µg aluminium hydroxide in a 0·5 mL aqueous solution, and the placebo contained the same volume of saline. Randomisation was done centrally by use of an interactive web response system, stratified by age (≥20 to <65 years and ≥65 years). Participants and investigators were masked to group assignment. The primary outcomes were to evaluate the safety, tolerability, and immunogenicity of MVC-COV1901 from day 1 (the day of the first dose) to day 57 (28 days after the second dose). Safety was assessed in all participants who received at least one dose. Immunogenicity was assessed by measuring geometric mean titres (GMTs) and seroconversion rates of neutralising antibody and antigen-specific IgG in the per-protocol population. This study is registered with ClinicalTrials.gov, NCT04695652. FINDINGS: Of 4173 individuals screened between Dec 30, 2020, and April 2, 2021, 3854 were enrolled and randomly assigned: 3304 to the MVC-COV1901 group and 550 to the placebo group. A total of 3844 participants (3295 in the MVC-COV1901 group and 549 in the placebo group) were included in the safety analysis set, and 1053 participants (903 and 150) had received both doses and were included in the per-protocol immunogenicity analysis set. From the start of this phase 2 trial to the time of interim analysis, no vaccine-related serious adverse events were recorded. The most common solicited adverse events in all study participants were pain at the injection site (2346 [71·2%] of 3295 in the MVC-COV1901 group and 128 [23·3%] of 549 in the placebo group), and malaise or fatigue (1186 [36·0%] and 163 [29·7%]). Fever was rarely reported (23 [0·7%] and two [0·4%]). At 28 days after the second dose of MVC-COV1901, the wild-type SARS-CoV-2 neutralising antibody GMT was 662·3 (95% CI 628·7-697·8; 408·5 IU/mL), the GMT ratio (geometric mean fold increase in titres at day 57 vs baseline) was 163·2 (155·0-171·9), and the seroconversion rate was 99·8% (95% CI 99·2-100·0). INTERPRETATION: MVC-COV1901 has a good safety profile and elicits promising immunogenicity responses. These data support MVC-COV1901 to enter phase 3 efficacy trials. FUNDING: Medigen Vaccine Biologics and Taiwan Centres for Disease Control, Ministry of Health and Welfare.

Safety and immunogenicity of a Recombinant Stabilized Prefusion SARS-CoV-2 Spike Protein Vaccine (MVC-COV1901) Adjuvanted with CpG 1018 and Aluminum Hydroxide in healthy adults: A Phase 1, dose-escalation study.

BACKGROUND: This was a phase 1, dose-escalation open-label trial to evaluate the safety and immunogenicity of MVC-COV1901, a SARS-CoV-2 S-2P protein vaccine adjuvanted with aluminum hydroxide and CpG 1018. METHODS: Between September 28 and November 13 2020, 77 participants were screened. Of these, 45 healthy adults from 20 to 49 years of age were to be administered two doses of MVC-COV1901 in doses of 5 µg, 15 µg, or 25 µg of spike protein at 28 days apart. There were 15 participants in each dose group; all were followed for 28 days after the second dose at the time of the interim analysis. Adverse events and laboratory data were recorded for the safety evaluation. Blood samples were collected for humoral, and cellular immune response at various time points. Trial Registration: ClinicalTrials.gov NCT04487210. FINDINGS: Solicited adverse events were mostly mild and similar. No subject experienced fever. After the second dose, the geometric mean titers (GMTs) for SARS-CoV-2 spike-specific immunoglobulin G were 7178.2, 7746.1, 11,220.6 in the 5 µg, 15 µg, and 25 µg dose groups, respectively. The neutralizing activity were detected in both methods. (Day 43 GMTs, 538.5, 993.1, and 1905.8 for pseudovirus; and 33.3, 76.3, and 167.4 for wild-type virus). The cellular immune response induced by MVC-COV1901 demonstrated substantially higher numbers of IFN-γ- producing cells, suggesting a Th1-skewed immune response. INTERPRETATION: The MVC-COV1901 vaccine was well tolerated and elicited robust immune responses and is suitable for further development. FUNDING: Medigen Vaccine Biologics Corporation.

Dose-Related Aberrant Inhibition of Intracellular Perforin Expression by S1 Subunit of Spike Glycoprotein That Contains Receptor-Binding Domain from SARS-CoV-2.

Studies had shown that severe cases of COVID-19 tend to have high viral loads and correlate with functional impairment of cytotoxic lymphocytes, and the features of cytokine storm syndrome are similar to manifestations of severe influenza that have been partially explained by suppressed perforin expression. To test the hypothesis that the spike glycoprotein from SARS-CoV-2 may inhibit the perforin expression, we determined the kinetics of immune responses of CD8+ T cells to low dose (LD) or high dose (HD) of S1 stimulation through an in vitro dendritic cell (DC)-T cell model over seven days of incubation. The cytotoxic activity and intracellular perforin expression of CD8+ T cells induced by HD-S1-presenting DCs were aberrantly lower than those induced by LD-S1-presenting DCs from day three of incubation. Discrepantly, the levels of lymphoproliferation and cytokine (interferon-γ and tumor necrosis factor-α) production induced by HD-S1-presenting DCs were significantly higher than those induced by LD-S1-presenting DCs from day four. The dose-related responses between doses of S1 and intracellular perforin expression showed a significant linear correlation with a negative slope. In conclusion, the S1 subunit may suppress the perforin expression in CD8+ T cells to decrease the cytotoxic capacity to kill spike-presenting cells in a dose-dependent manner; the persistence of antigen presentation may result in an overproduction of interferon-γ and subsequent proinflammatory cytokines. That may help explain the insufficient cytotoxicity against high quantities of viruses or highly replicated strains of SARS-CoV-2 in severe cases of COVID-19.

Evolution of SARS-CoV-2 neutralizing antibody in an HIV-positive patient with COVID-19.

We presented the clinical course and immune responses of a well-controlled HIV-positive patient with COVID-19. The clinical presentation and antibody production to SARS-CoV-2 were similar to other COVID-19 patients without HIV infection. Neutralizing antibody reached a plateau from 26th to 47th day onset but decreased on 157th day after symptoms.

A cross-sectional seroprevalence for COVID-19 among healthcare workers in a tertially care hospital in Taiwan.

BACKGROUND: Healthcare workers (HCWs) are at the frontline during the pandemic of COVID-19 globally. According to the WHO situation report at April 17, there were 22, 073 HCWs contracted the infection. Whether the infection control policy and practice in the hospital setting can protect the HCWs is an important issue. METHODS: We performed a cross-sectional serology study in a tertiary care hospital in Taiwan to explore the sero-prevalence rate among HCWs. The participants are enrolled on a voluntary basis. A structured questionnaire was collected to gather the epidemiology character and risk factors for potential exposure. ELISA tests as Architect SARS-CoV-2 IgG (Abbott) and Elecsys Anti-SARS-CoV-2 assay (Roche) were used to detect antibody responses. If any of the tests was positive, a western blot assay was used for confirmation. RESULTS: There were 194 HCWs participated during July 1 to Aug. 31, 2020. The mean age was 36.3 ± 10.4. More than half of the participants had possible hospital associated risk for COVID-19 exposure (110/192, 57.3%) and 64 had possible community risk for COVID-19 exposure (64/194, 33.0%). There was only one participant had positive test by Architect IgG test and confirmed to be negative for seasonal coronavirus and SARS-CoV-2 antibody. (Mikrogen Diagnostik, Germany). CONCLUSION: The cross-sectional serology study in a tertiary care hospital in Taiwan revealed no HCWs had positive serology response to SARS-CoV-2. We believe that the infection control policy and practice in the hospital and in the community are both important to prevent the disease transmission.