Differential immunogenicity of homologous versus heterologous boost in Ad26.COV2.S vaccine recipients.

Protection offered by COVID-19 vaccines wanes over time, requiring an evaluation of different boosting strategies to revert such a trend and enhance the quantity and quality of Spike-specific humoral and cellular immune responses. These immunological parameters in homologous or heterologous vaccination boosts have thus far been studied for mRNA and ChAdOx1 nCoV-19 vaccines, but knowledge on individuals who received a single dose of Ad26.COV2.S is lacking. We studied Spike-specific humoral and cellular immunity in Ad26.COV2.S vaccinated individuals (n=55) who were either primed with Ad26.COV2.S only (n=13), or boosted with a homologous (Ad26.COV2.S, n=28) or heterologous (BNT162b2, n=14) second dose. We compared our findings with the results found in individuals vaccinated with a single (n=16) or double (n=44) dose of BNT162b2. We observed that a strategy of heterologous vaccination enhanced the quantity and breadth of both, Spike-specific humoral and cellular immunity in Ad26.COV2.S vaccinated. In contrast, the impact of homologous boost was quantitatively minimal in Ad26.COV2.S vaccinated and Spike-specific antibodies and T cells were narrowly focused to the S1 region. Although a direct association between quantity and quality of immunological parameters and in vivo protection has not been demonstrated, the immunological features of Spike-specific humoral and cellular immune responses support the utilization of a heterologous strategy of vaccine boost in individuals who received Ad26.COV2.S vaccination.

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The Efficacy of a Long-Acting Injectable Selenium Preparation Administered to Pregnant Ewes and Lambs

Animals ◽

10.3390/ani11041076 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1076

Author(s):

Stanisław Milewski ◽

Przemysław Sobiech ◽

Justyna Błażejak-Grabowska ◽

Roman Wójcik ◽

Katarzyna Żarczyńska ◽

...

Keyword(s):

Immune Responses ◽

Defense Mechanisms ◽

Dry Matter ◽

Milk Composition ◽

Immunological Parameters ◽

Cellular Immune Responses ◽

Long Acting ◽

Cellular Immune ◽

Animal Care

The aim of this study was to evaluate the effects of a long-acting selenium (Se) preparation administered to sheep. The experiment was conducted on 30 dams and 36 lambs divided into three equal groups of 10 dams and 12 lambs each: Control—C, and two experimental groups—E (Se administered to pregnant ewes) and EI (Se administered directly to lambs after the colostral period). The Se preparation (Barium Selenate Injection, BVP Animal Care, 50 mg/mL) was administered by injection at 1 mL/50 kg (1 mg Se/kg) body weight (BW) to group E ewes in the third month of pregnancy (between 70 and 90 days) and to group EI lambs between 4 and 7 days of age. The following parameters were determined: Se concentration in the blood of ewes, milk yield, milk composition, Se concentration in milk; hematological, biochemical, and immunological parameters and Se concentration in the blood of lambs; growth rate and in vivo measurements of lean meat and fat content in lambs. Barium selenate significantly improved the Se status of dams and lambs, regardless of whether it was administered to pregnant ewes or directly to lambs in the first week of their life. The milk of ewes receiving the Se preparation was characterized by higher concentrations of fat and dry matter. The Se preparation induced significant changes in immunological parameters, thus enhancing defense mechanisms in lambs. The Se preparation exerted more stimulatory effects on humoral and cellular immune responses when administered directly to lambs after the colostral period (group EI) than to pregnant ewes (group E). The results of this study indicate that the long-acting Se preparation delivers benefits to sheep by boosting their immunity and, therefore, improving performance.

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A Combined Adjuvant TF–Al Consisting of TFPR1 and Aluminum Hydroxide Augments Strong Humoral and Cellular Immune Responses in Both C57BL/6 and BALB/c Mice

Vaccines ◽

10.3390/vaccines9121408 ◽

2021 ◽

Vol 9 (12) ◽

pp. 1408

Author(s):

Qiao Li ◽

Zhihua Liu ◽

Yi Liu ◽

Chen Liang ◽

Jiayi Shu ◽

...

Keyword(s):

Immune Responses ◽

Vaccine Development ◽

Inbred Mouse ◽

Effective Vaccine ◽

Mouse Strains ◽

Cellular Immune Responses ◽

Recombinant Hbsag ◽

Cellular Immune

TFPR1 is a novel adjuvant for protein and peptide antigens, which has been demonstrated in BALB/c mice in our previous studies; however, its adjuvanticity in mice with different genetic backgrounds remains unknown, and its adjuvanticity needs to be improved to fit the requirements for various vaccines. In this study, we first compared the adjuvanticity of TFPR1 in two commonly used inbred mouse strains, BALB/c and C57BL/6 mice, in vitro and in vivo, and demonstrated that TFPR1 activated TLR2 to exert its immune activity in vivo. Next, to prove the feasibility of TFPR1 acting as a major component of combined adjuvants, we prepared a combined adjuvant, TF–Al, by formulating TFPR1 and alum at a certain ratio and compared its adjuvanticity with that of TFPR1 and alum alone using OVA and recombinant HBsAg as model antigens in both BALB/c and C57BL/6 mice. Results showed that TFPR1 acts as an effective vaccine adjuvant in both BALB/c mice and C57BL/6 mice, and further demonstrated the role of TLR2 in the adjuvanticity of TFPR1 in vivo. In addition, we obtained a novel combined adjuvant, TF–Al, based on TFPR1, which can augment antibody and cellular immune responses in mice with different genetic backgrounds, suggesting its promise for vaccine development in the future.

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Heat shock protein 70 / MAGE-1 tumor vaccine can enhance the potency of MAGE-1–specific cellular immune responses in vivo

Cancer Immunology Immunotherapy ◽

10.1007/s00262-004-0536-6 ◽

2004 ◽

Vol 53 (9) ◽

pp. 825-834 ◽

Cited By ~ 13

Author(s):

Jing Ye ◽

Guang-Sheng Chen ◽

Hong-Ping Song ◽

Zeng-Shan Li ◽

Ya-Yu Huang ◽

...

Keyword(s):

Heat Shock ◽

Immune Responses ◽

Heat Shock Protein ◽

Heat Shock Protein 70 ◽

Tumor Vaccine ◽

Cellular Immune Responses ◽

Cellular Immune

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Enhancement of antibody and cellular immune responses to malaria DNA vaccines by in vivo electroporation

Vaccine ◽

10.1016/j.vaccine.2007.06.036 ◽

2007 ◽

Vol 25 (36) ◽

pp. 6635-6645 ◽

Cited By ~ 29

Author(s):

Carlota Dobaño ◽

Georg Widera ◽

Dietmar Rabussay ◽

Denise L. Doolan

Keyword(s):

Immune Responses ◽

Dna Vaccines ◽

In Vivo Electroporation ◽

Cellular Immune Responses ◽

Cellular Immune

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Induction of Broad-Based Immunity and Protective Efficacy by Self-amplifying mRNA Vaccines Encoding Influenza Virus Hemagglutinin

Journal of Virology ◽

10.1128/jvi.01786-15 ◽

2015 ◽

Vol 90 (1) ◽

pp. 332-344 ◽

Cited By ~ 54

Author(s):

Michela Brazzoli ◽

Diletta Magini ◽

Alessandra Bonci ◽

Scilla Buccato ◽

Cinzia Giovani ◽

...

Keyword(s):

T Cells ◽

Influenza Virus ◽

Immune Responses ◽

Upper Respiratory Tract ◽

Vaccine Platform ◽

Major Health Problem ◽

Cellular Immune Responses ◽

Influenza Virus Hemagglutinin ◽

Cellular Immune ◽

The Impact

ABSTRACTSeasonal influenza is a vaccine-preventable disease that remains a major health problem worldwide, especially in immunocompromised populations. The impact of influenza disease is even greater when strains drift, and influenza pandemics can result when animal-derived influenza virus strains combine with seasonal strains. In this study, we used the SAM technology and characterized the immunogenicity and efficacy of a self-amplifying mRNA expressing influenza virus hemagglutinin (HA) antigen [SAM(HA)] formulated with a novel oil-in-water cationic nanoemulsion. We demonstrated that SAM(HA) was immunogenic in ferrets and facilitated containment of viral replication in the upper respiratory tract of influenza virus-infected animals. In mice, SAM(HA) induced potent functional neutralizing antibody and cellular immune responses, characterized by HA-specific CD4 T helper 1 and CD8 cytotoxic T cells. Furthermore, mice immunized with SAM(HA) derived from the influenza A virus A/California/7/2009 (H1N1) strain (Cal) were protected from a lethal challenge with the heterologous mouse-adapted A/PR/8/1934 (H1N1) virus strain (PR8). Sera derived from SAM(H1-Cal)-immunized animals were not cross-reactive with the PR8 virus, whereas cross-reactivity was observed for HA-specific CD4 and CD8 T cells. Finally, depletion of T cells demonstrated that T-cell responses were essential in mediating heterologous protection. If the SAM vaccine platform proves safe, well tolerated, and effective in humans, the fully synthetic SAM vaccine technology could provide a rapid response platform to control pandemic influenza.IMPORTANCEIn this study, we describe protective immune responses in mice and ferrets after vaccination with a novel HA-based influenza vaccine. This novel type of vaccine elicits both humoral and cellular immune responses. Although vaccine-specific antibodies are the key players in mediating protection from homologous influenza virus infections, vaccine-specific T cells contribute to the control of heterologous infections. The rapid production capacity and the synthetic origin of the vaccine antigen make the SAM platform particularly exploitable in case of influenza pandemic.

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Acute HIV infection: the impact of anti-retroviral treatment on cellular immune responses

Clinical & Experimental Immunology ◽

10.1111/j.1365-2249.2007.03437.x ◽

2007 ◽

Vol 149 (2) ◽

pp. 211-216 ◽

Cited By ~ 8

Author(s):

C. B. Hicks ◽

C. Gay ◽

G. Ferrari

Keyword(s):

Immune Responses ◽

Hiv Infection ◽

Acute Hiv Infection ◽

Cellular Immune Responses ◽

Acute Hiv ◽

Cellular Immune ◽

The Impact

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Humoral and cellular immunity and the safety of COVID-19 vaccines: a summary of data published by 21 May 2021

International Immunology ◽

10.1093/intimm/dxab061 ◽

2021 ◽

Vol 33 (10) ◽

pp. 529-540

Author(s):

Kun Xu ◽

Lianpan Dai ◽

George F Gao

Keyword(s):

Immune Responses ◽

Viral Genome ◽

Vaccine Development ◽

Published Data ◽

Humoral And Cellular Immunity ◽

Cellular Immune Responses ◽

Rapid Responses ◽

Study Results ◽

Protection Efficacy ◽

Cellular Immune

Abstract Coronavirus disease 2019 (COVID-19) has caused millions of deaths, and serious consequences to public health, economies and societies. Rapid responses in vaccine development have taken place since the isolation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the release of the viral genome sequence. By 21 May 2021, 101 vaccines were under clinical trials, and published data were available for 18 of them. Clinical study results from some vaccines indicated good immunogenicity and acceptable reactogenicity. Here, we focus on these 18 vaccines that had published clinical data to dissect the induced humoral and cellular immune responses as well as their safety profiles and protection efficacy.

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