ABSTRACT
The HIPRA-HH-2 was a multicentre, randomized, active-controlled, double-blind, non-inferiority phase IIb clinical trial to compare the immunogenicity and safety of a heterologous booster with PHH-1V adjuvanted recombinant vaccine versus a homologous booster with mRNA vaccine. Interim results showed a strong humoral and cellular immune response against the SARS-CoV-2 Wuhan-Hu-1 strain and the Beta, Delta, and Omicron BA.1 variants up to day 98 after dosing. Here we report that these humoral and cellular responses after PHH-1V dosing are sustained up to 6 months. These results are observed both when including or not participants who reported SARS-CoV-2 infection and in a high-risk population ([≥]65 years). Additional analysis revealed a non-inferiority of PHH-1V booster in eliciting neutralizing antibodies also for SARS-CoV-2 Omicron XBB.1.5 when compared to mRNA vaccine after 6 months. The PHH-1V vaccine provides long-lasting protection against a wide variety of SARS-CoV-2 emerging variants to prevent severe COVID-19. ClinicalTrials.gov Identifier: NCT05142553
Subject(s)
COVID-19ABSTRACT
The SARS-CoV-2 pandemic made evident that we count with few coronavirus-fighting drugs. Here we aimed to identify a cost-effective antiviral with broad spectrum activity and high safety and tolerability profiles. We began elaborating a list of 116 drugs previously used to treat other pathologies or characterized in pre-clinical studies with potential to treat coronavirus infections. We next employed molecular modelling tools to rank the 44 most promising inhibitors and tested their efficacy as antivirals against a panel of alpha and beta coronavirus, e.g., the HCoV-229E and SARS-CoV-2 viruses. Four drugs, OSW-1, U18666A, hydroxypropyl-beta-cyclodextrin (HbetaCD) and phytol, showed antiviral activity against both HCoV-229E (in MRC5 cells) and SARS-CoV-2 (in Vero E6 cells). The mechanism of action of these compounds was studied by transmission electron microscopy (TEM) and by testing their capacity to inhibit the entry of SARS-CoV-2 pseudoviruses in ACE2-expressing HEK-293T cells. The entry was inhibited by HbetaCD and U18666A, yet only HbetaCD could inhibit SARS-CoV-2 replication in the pulmonary cells Calu-3. With these results and given that cyclodextrins are widely used for drug encapsulation and can be safely administered to humans, we further tested 6 native and modified cyclodextrins, which confirmed {beta}-cyclodextrins as the most potent inhibitors of SARS-CoV-2 replication in Calu-3 cells. All accumulated data points to beta-cyclodextrins as promising candidates to be used in the therapeutic treatments for SARS-CoV-2 and possibly other respiratory viruses.
Subject(s)
Coronavirus InfectionsABSTRACT
Summary Background: We report safety, tolerability, and immunogenicity of a recombinant protein RBD-fusion heterodimeric vaccine against SARS-CoV-2 (PHH-1V). Methods: A dose-escalation, phase 1-2a, randomized clinical trial was performed in Catalonia, Spain. Each cohort had one safety sentinel that received PHH-1V vaccine of the corresponding dose, and remaining participants were randomly assigned to receive PHH-1V formulations [10mcg (n=5), 20mcg (n=10), 40mcg (n=10)] or control BNT162b2 (n=5). Two intramuscular doses (0-21 days) were administered. Primary endpoint was solicited events 7 days after each vaccination and secondary-exploratory endpoints were humoral and cellular immunogenicity. Findings: 30 young healthy adults were enrolled, thirteen were female. Vaccines were safe, well tolerated. The most common solicited events for all groups were tenderness and pain at the site of injection. The proportion of subjects with at least one reported local and/or systemic solicited adverse events (AE) after first or second vaccine dose were lowest in PHH-1V (n=21, 84%) than control group (n=5, 100%). AE were mild to moderate, and no severe AE nor AE of special interest were reported. All participants had a >4-fold change at day 35 in total binding antibodies from baseline. Variants of concern (VOC) alpha, beta, delta and gamma were evaluated using a SARS-CoV-2 pseudovirus-based neutralization assay. All groups had a significant geometric mean fold rise (p
Subject(s)
PainABSTRACT
Summary Background A SARS-CoV-2 protein-based heterodimer vaccine, PHH-1V, has been shown to be safe and well-tolerated in healthy young adults in a first-in-human, Phase I/IIa study dose-escalation trial. Here, we report the interim results of the Phase IIb HH-2, where the immunogenicity and safety of a heterologous booster with PHH-1V is assessed versus a homologous booster with BNT162b2 at 14 and 98 days after vaccine administration. Methods The HH-2 study is an ongoing multicentre, randomised, active-controlled, double-blind, non-inferiority Phase IIb trial, where participants 18 years or older who had received two doses of BNT162b2 were randomly assigned in a 2:1 ratio to receive a booster dose of vaccine – either heterologous (PHH-1V group) or homologous (BNT162b2 group) – in 10 centres in Spain. Eligible subjects were allocated to treatment stratified by age group (18-64 versus ≥65 years) with approximately 10% of the sample enrolled in the older age group. The endpoints were humoral immunogenicity measured by changes in levels of neutralizing antibodies against the ancestral Wuhan-Hu-1 strain and different variants of SARS-CoV-2 after the PHH-1V or the BNT162b2 boost, the T-cell responses towards the SARS-CoV-2 spike glycoprotein peptides and the safety and tolerability of PHH-1V as a boost. This study is ongoing and is registered with ClinicalTrials.gov, NCT05142553 . Findings From 15 November 2021, 782 adults were randomly assigned to PHH-1V (n=522) or BNT162b2 (n=260) boost vaccine groups. The geometric mean titre (GMT) ratio of neutralizing antibodies on days 14 and 98, shown as BNT162b2 active control versus PHH-1V, was, respectively, 1·68 (p<0·0001) and 0·87 (p=0·43) for the ancestral Wuhan-Hu-1 strain; 0·61 (p<0·0001) and 0·57 (p=0·0064) for the beta variant; 1·01 (p=0·89) and 0·52 (p=0·0003) for the delta variant; and 0·59 (p=<0·0001) and 0·56 (p=0·0026) for the omicron variant. Additionally, PHH-1V as a booster dose induced a significant increase of CD4 + and CD8 + T-cells expressing IFN-γ on day 14. There were 458 participants who experienced at least one adverse event (89·3%) in the PHH-1V and 238 (94·4%) in the BNT162b2 group. The most frequent adverse events were injection site pain (79·7% and 89·3%), fatigue (27·5% and 42·1%) and headache (31·2 and 40·1%) for the PHH-1V and the BNT162b2 groups, respectively. A total of 52 COVID-19 cases occurred from day 14 post-vaccination (10·14%) for the PHH-1V group and 30 (11·90%) for the BNT162b2 group (p=0·45), and none of the subjects developed severe COVID-19. Interpretation Our interim results from the Phase IIb HH-2 trial show that PHH-1V as a heterologous booster vaccine, when compared to BNT162b2, elicits a strong and sustained neutralizing antibody response against Wuhan-Hu-1 strain, and a superior one concerning the previous circulating beta and delta SARS-CoV-2 variants, as well as the currently circulating omicron. Moreover, the PHH-1V boost also induces a strong and balanced T-cell response. Concerning the safety profile, subjects in the PHH-1V group report significantly fewer adverse events than those in the BNT162b2 group, most of mild intensity, and both vaccine groups present comparable COVID-19 breakthrough cases, none of them severe. Funding HIPRA SCIENTIFIC, S.L.U.
Subject(s)
COVID-19ABSTRACT
The pandemic caused by the new coronavirus SARS-CoV-2 has made evident the need for broad-spectrum, efficient antiviral treatments to combat emerging and re-emerging viruses. Plitidepsin is an antitumor agent of marine origin that has also shown a potent pre-clinical efficacy against SARS-CoV-2. Plitidepsin targets the host protein eEF1A (eukaryotic translation factor 1 alpha 1) and affects viral infection at an early, post-entry step. Because electron microscopy is a valuable tool to study virus-cell interactions and the mechanism of action of antiviral drugs, in this work we have used transmission electron microscopy (TEM) to evaluate the effects of plitidepsin in SARS-CoV-2 infection in cultured Vero E6 cells 24 and 48h post-infection. In the absence of plitidepsin, TEM morphological analysis showed double-membrane vesicles (DMVs), organelles that support coronavirus genome replication, single-membrane vesicles with viral particles, large vacuoles with groups of viruses and numerous extracellular virions attached to the plasma membrane. When treated with plitidepsin, no viral structures were found in SARS-CoV-2-infected Vero E6 cells. Immunogold detection of SARS-CoV-2 nucleocapsid (N) protein and double-stranded RNA (dsRNA) provided clear signals in cells infected in the absence of plitidepsin, but complete absence in cells infected and treated with plitidepsin. The present study shows that plitidepsin completely blocks the biogenesis of viral replication organelles and the morphogenesis of virus progeny. Electron microscopy morphological analysis coupled to immunogold labeling of SARS-CoV-2 products offers a unique approach to understand how antivirals such as plitidepsin work.
Subject(s)
Infections , Severe Acute Respiratory Syndrome , Virus Diseases , COVID-19ABSTRACT
SARS-CoV-2 variants display enhanced transmissibility and/or immune evasion and can be generated in humans or animals, like minks, thus generating new reservoirs. The continuous surveillance of animal susceptibility to new variants is necessary to predict pandemic evolution. In this study we demonstrate that, compared to the B.1 SARS-CoV-2 variant, K18-hACE2 transgenic mice challenged with the B.1.351 variant displayed a faster progression of infection. Furthermore, we also report that B.1.351 can establish infection in wildtype mice, while B.1 cannot. B.1.351-challenged wildtype mice showed a milder infection than transgenic mice, confirmed by detectable viral loads in oropharyngeal swabs and tissues, lung pathology, immunohistochemistry and serology. In silico models supported these findings by demonstrating that the Spike mutations in B.1.351 resulted in increased affinity for both human and murine ACE2 receptors. Overall, this study highlights the plasticity of SARS-CoV-2 animal susceptibility landscape, which may contribute to viral persistence and expansion.
ABSTRACT
COVID-19 pandemic is not yet under control by vaccination, and effective antivirals are critical for preparedness. Here we report that macrophages and dendritic cells, key antigen presenting myeloid cells (APCs), are largely resistant to SARS-CoV-2 infection. APCs effectively captured viruses within cellular compartments that lead to antigen degradation. Macrophages sense SARS-CoV-2 and released higher levels of cytokines, including those related to cytokine storm in severe COVID-19. The sialic acid-binding Ig-like lectin 1 (Siglec-1/CD169) present on APCs, which interacts with sialylated gangliosides on membranes of retroviruses or filoviruses, also binds SARS-CoV-2 via GM1. Blockage of Siglec-1 receptors by monoclonal antibodies reduces SARS-CoV-2 uptake and transfer to susceptible target cells. APCs expressing Siglec-1 and carrying SARS-CoV-2 are found in pulmonary tissues of non-human primates. Single cell analysis reveals the in vivo induction of cytokines in those macrophages. Targeting Siglec-1 could offer cross-protection against SARS-CoV-2 and other enveloped viruses that exploit APCs for viral dissemination, including those yet to come in future outbreaks.