Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 7 de 7
Filter
1.
JCI Insight ; 7(11)2022 06 08.
Article in English | MEDLINE | ID: covidwho-1892019

ABSTRACT

SARS-CoV-2 has been confirmed in over 450 million confirmed cases since 2019. Although several vaccines have been certified by the WHO and people are being vaccinated on a global scale, it has been reported that multiple SARS-CoV-2 variants can escape neutralization by antibodies, resulting in vaccine breakthrough infections. Bacillus Calmette-Guérin (BCG) is known to induce heterologous protection based on trained immune responses. Here, we investigated whether BCG-induced trained immunity protected against SARS-CoV-2 in the K18-hACE2 mouse model. Our data demonstrate that i.v. BCG (BCG-i.v.) vaccination induces robust trained innate immune responses and provides protection against WT SARS-CoV-2, as well as the B.1.617.1 and B.1.617.2 variants. Further studies suggest that myeloid cell differentiation and activation of the glycolysis pathway are associated with BCG-induced training immunity in K18-hACE2 mice. Overall, our study provides the experimental evidence that establishes a causal relationship between BCG-i.v. vaccination and protection against SARS-CoV-2 challenge.


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , BCG Vaccine , COVID-19/prevention & control , Humans , Melphalan , Mice , gamma-Globulins
2.
Acta Biomater ; 148: 133-141, 2022 08.
Article in English | MEDLINE | ID: covidwho-1885570

ABSTRACT

Microneedles can realize the intradermal and transdermal delivery of drugs. However, most conventional microneedles made of metal, polymer and ceramics are unsuitable for the delivery of mRNA drugs that are fragile and temperature-sensitive. This study explores the usage of cryomicroneedles (CryoMNs) for the intradermal delivery of mRNA molecules. Taking luciferase mRNA as an example, we first optimize the formulation of CryoMNs to maximize mRNA stability. Later, in the mouse model, we compare the delivery efficiency with the conventional subcutaneous injection for both the luciferase mRNA and COVID-19 Comirnaty mRNA vaccines, where CryoMNs delivered mRNA vaccines successfully induce specific B-cell antibody, neutralizing activity and T-cell responses. STATEMENT OF SIGNIFICANCE: mRNA vaccines are fragile and temperature-sensitive, so they are mainly delivered by intramuscular injection that often causes pain and requires clinical expertise to immunize patients. Microneedles permit convenient, fast and safe vaccination. However, existing microneedle platforms are ineffective to protect the integrity of mRNA vaccines in fabrication, storage, and administration. This work utilizes cryomicroneedles (CryoMNs) technology to intradermally deliver mRNA. In the mouse model, CryoMNs are compared with the subcutaneous injection for the delivery efficiency of both the luciferase mRNA and COVID-19 Comirnaty mRNA vaccines, where CryoMNs delivered mRNA vaccines successfully produce specific B-cell antibodies, T-cell responses, and neutralizing activity. This work is expected to provide a new delivery strategy for the emerging mRNA therapeutics.


Subject(s)
COVID-19 , Animals , COVID-19/prevention & control , Drug Delivery Systems , Injections, Intradermal , Mice , Needles , RNA, Messenger/genetics , Vaccination
3.
Front Immunol ; 13: 861050, 2022.
Article in English | MEDLINE | ID: covidwho-1785349

ABSTRACT

It has been reported that multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) including Alpha, Beta, Gamma, and Delta can reduce neutralization by antibodies, resulting in vaccine breakthrough infections. Virus-antiserum neutralization assays are typically performed to monitor potential vaccine breakthrough strains. However, experiment-based methods took several weeks whether newly emerging variants can break through current vaccines or therapeutic antibodies. To address this, we sought to establish a computational model to predict the antigenicity of SARS-CoV-2 variants by sequence alone. In this study, we firstly identified the relationship between the antigenic difference transformed from the amino acid sequence and the antigenic distance from the neutralization titers. Based on this correlation, we obtained a computational model for the receptor-binding domain (RBD) of the spike protein to predict the fold decrease in virus-antiserum neutralization titers with high accuracy (~0.79). Our predicted results were comparable to experimental neutralization titers of variants, including Alpha, Beta, Delta, Gamma, Epsilon, Iota, Kappa, and Lambda, as well as SARS-CoV. Here, we predicted the fold of decrease of Omicron as 17.4-fold less susceptible to neutralization. We visualized all 1,521 SARS-CoV-2 lineages to indicate variants including Mu, B.1.630, B.1.633, B.1.649, and C.1.2, which can induce vaccine breakthrough infections in addition to reported VOCs Beta, Gamma, Delta, and Omicron. Our study offers a quick approach to predict the antigenicity of SARS-CoV-2 variants as soon as they emerge. Furthermore, this approach can facilitate future vaccine updates to cover all major variants. An online version can be accessed at http://jdlab.online.


Subject(s)
Antigens, Viral , COVID-19 Vaccines , COVID-19 , SARS-CoV-2 , Antibodies, Neutralizing , Antibodies, Viral , Antigens, Viral/immunology , COVID-19/prevention & control , COVID-19 Vaccines/immunology , Humans , Immune Sera , Neutralization Tests , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics
4.
J Immunol Res ; 2021: 5531220, 2021.
Article in English | MEDLINE | ID: covidwho-1232374

ABSTRACT

The nucleocapsid protein (NP) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) contains immunogenic epitopes that can induce cytotoxic T lymphocyte (CTL) against viral infection. This makes the nucleocapsid protein a suitable candidate for developing a vaccine against SARS-CoV-2 infection. This article reports the intradermal delivery of NP antigen using dissolvable microneedle skin patches that could induce both significant B cell and T cell responses.


Subject(s)
Antibodies, Viral/blood , COVID-19 Vaccines/immunology , COVID-19/prevention & control , Coronavirus Nucleocapsid Proteins/immunology , SARS-CoV-2/immunology , T-Lymphocytes, Cytotoxic/immunology , Animals , B-Lymphocytes/immunology , COVID-19 Vaccines/administration & dosage , Coronavirus Nucleocapsid Proteins/administration & dosage , Enzyme-Linked Immunosorbent Assay , Injections, Intradermal/methods , Mice , Mice, Inbred BALB C , Phosphoproteins/administration & dosage , Phosphoproteins/immunology
5.
Emerg Microbes Infect ; 10(1): 874-884, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1199439

ABSTRACT

The Coronavirus Disease 2019 (COVID-19) pandemic is unlikely to abate until sufficient herd immunity is built up by either natural infection or vaccination. We previously identified ten linear immunodominant sites on the SARS-CoV-2 spike protein of which four are located within the RBD. Therefore, we designed two linkerimmunodominant site (LIS) vaccine candidates which are composed of four immunodominant sites within the RBD (RBD-ID) or all the 10 immunodominant sites within the whole spike (S-ID). They were administered by subcutaneous injection and were tested for immunogenicity and in vivo protective efficacy in a hamster model for COVID-19. We showed that the S-ID vaccine induced significantly better neutralizing antibody response than RBD-ID and alum control. As expected, hamsters vaccinated by S-ID had significantly less body weight loss, lung viral load, and histopathological changes of pneumonia. The S-ID has the potential to be an effective vaccine for protection against COVID-19.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/prevention & control , Immunodominant Epitopes/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Animals , Cricetinae , Female , HEK293 Cells , Humans , Male , Mesocricetus , Mice , Mice, Inbred BALB C , Vaccination
6.
Bioeng Transl Med ; 6(1): e10202, 2021 Jan.
Article in English | MEDLINE | ID: covidwho-985967

ABSTRACT

The S1 subunit of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein contains an immunogenic receptor-binding domain (RBD), which is a promising candidate for the development of a potential vaccine. This study demonstrated that intradermal delivery of an S-RBD vaccine using a dissolvable microneedle skin patch can induce both significant B-cell and significant T-cell responses against S-RBD. Importantly, the outcomes were comparable to that of conventional bolus injection.

SELECTION OF CITATIONS
SEARCH DETAIL