ABSTRACT
The overall success of worldwide mass vaccination in limiting the negative effect of the COVID-19 pandemics is inevitable, however, recent SARS-CoV-2 variants of concern, especially Omicron and its sub-lineages, efficiently evade humoral immunity mounted upon vaccination or previous infection. Thus, it is an important question whether these variants, or vaccines against them, induce anti-viral cellular immunity. Here we show that the mRNA vaccine BNT162b2 induces robust protective immunity in K18-hACE2 transgenic B-cell deficient (µMT) mice. We further demonstrate that the protection is attributed to cellular immunity depending on robust IFN-γ production. Viral challenge with SARS-CoV-2 Omicron BA.1 and BA.5.2 sub-variants induce boosted cellular responses in vaccinated µMT mice, which highlights the significance of cellular immunity against the ever-emerging SARS-CoV-2 variants evading antibody-mediated immunity. Our work, by providing evidence that BNT162b2 can induce significant protective immunity in mice that are unable to produce antibodies, thus highlights the importance of cellular immunity in the protection against SARS-CoV-2.
Subject(s)
COVID-19 Vaccines , COVID-19 , Immunity, Cellular , Animals , Humans , Mice , Antibodies , Antibodies, Neutralizing , Antibodies, Viral , BNT162 Vaccine , COVID-19/prevention & control , Interferon-gamma , SARS-CoV-2 , COVID-19 Vaccines/immunologyABSTRACT
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/immunologyABSTRACT
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 , VaccinationABSTRACT
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.
ABSTRACT
OBJECTIVE: To investigate the prevalence of respiratory viral infections in patients with primary immunodeficiency disease (PID) during hematopoietic stem cell transplantation. METHODS: 108 specimens of nasopharyngeal aspirate were collected from 22 PID patients before and after hematopoietic stem cell transplantation from July 2016 to July 2018 in the Department of Hematology. The TR-PCR was used to detect for respiratory viruses including respiratory syncytial virus(RSV)ï¼human metapneumoviros(hMPV)ï¼coronavirus(CoV) and parainfluenza 1-3 (PIV1-3). And the clinical characteristics and co-infection were analyzed. RESULTS: Among the total 108 specimens, viral pathogens were identified in 41 (37.96%) specimens. Among which the pathogens of highest detection rate was RSV (25.9%). Different types of PID showed different virus infection rates, among which the highest infection rate was severe combined immunodeficiency disease (SCID) patients, with the virus detection rate was 57.9%. The incidence of co-infection with two or more than two viruses was 19.5%. CONCLUSION: Patients with PID who undergo hematopoietic stem cell transplantation are more susceptible to respiratory viruses. RSV is an important respiratory tract virus pathogen after hematopoietic stem cell transplantation.