164 results match your criteria ty21a immunization


Age-dependency of terminal ileum tissue resident memory T cell responsiveness profiles to S. Typhi following oral Ty21a immunization in humans.

Immun Ageing 2021 Apr 19;18(1):19. Epub 2021 Apr 19.

Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.

Background: The impact of aging on the immune system is unequivocal and results in an altered immune status termed immunosenescence. In humans, the mechanisms of immunosenescence have been examined almost exclusively in blood. However, most immune cells are present in tissue compartments and exhibit differential cell (e. Read More

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Impact of BCG revaccination on the response to unrelated vaccines in a Ugandan adolescent birth cohort: randomised controlled trial protocol C for the 'POPulation differences in VACcine responses' (POPVAC) programme.

BMJ Open 2021 02 16;11(2):e040430. Epub 2021 Feb 16.

Immunomodulation and Vaccines Programme, MRC/UVRI and LSHTM Uganda Research Unit, Entebbe, Wakiso, Uganda.

Introduction: There is evidence that BCG immunisation may protect against unrelated infectious illnesses. This has led to the postulation that administering BCG before unrelated vaccines may enhance responses to these vaccines. This might also model effects of BCG on unrelated infections. Read More

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February 2021

Nonclinical safety evaluation of oral recombinant anti-human papilloma virus vaccine (RHPV 16 & 18): Regulatory toxicology studies in mice, rats and rabbits - An innovative approach.

Vaccine 2021 01 31;39(5):853-863. Epub 2020 Dec 31.

Advanced Centre for Preclinical Toxicology Studies, ICMR-National Institute of Nutrition, Jamai-Osmania, Hyderabad 500007, India. Electronic address:

Aim: The human papilloma virus (HPV) type 16 and 18 causes nearly 70% of uterine cervical cancers. Oral administration of live Salmonella typhi Ty21a, expressing major capsid proteins (L1) of HPV 16 and 18 is a potential choice for immunization in adolescent girls under low resource settings. Present study aimed to assess the nonclinical safety of recombinant S. Read More

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January 2021

Oral typhoid vaccine Ty21a elicits antigen-specific resident memory CD4 T cells in the human terminal ileum lamina propria and epithelial compartments.

J Transl Med 2020 02 25;18(1):102. Epub 2020 Feb 25.

Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.

Background: Salmonella enterica serovar Typhi (S. Typhi) is a highly invasive bacterium that infects the human intestinal mucosa and causes ~ 11.9-20. Read More

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February 2020

Differential functional patterns of memory CD4 and CD8 T-cells from volunteers immunized with Ty21a typhoid vaccine observed using a recombinant Escherichia coli system expressing S. Typhi proteins.

Vaccine 2020 01 16;38(2):258-270. Epub 2019 Oct 16.

Center for Vaccine Development and Global Health (CVD), Department of Pediatrics, University of Maryland School of Medicine, 685 West Baltimore Street, HSF1, Baltimore, MD 21201, USA.

It is widely accepted that CD4 and CD8 T-cells play a significant role in protection against Salmonella enterica serovar Typhi (S. Typhi), the causative agent of the typhoid fever. However, the antigen specificity of these T-cells remains largely unknown. Read More

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January 2020

Characteristics of regulatory T-cell populations before and after Ty21a typhoid vaccination in children and adults.

Clin Immunol 2019 06 4;203:14-22. Epub 2019 Apr 4.

Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA; Molecular Microbiology and Immunology Department, University of Maryland Graduate Program in Life Sciences, Baltimore, MD, USA; Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, USA; Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA. Electronic address:

Typhoid fever, caused by the pathogen Salmonella enterica serovar Typhi (S. Typhi), is a serious global health concern. Challenge studies with wild type S. Read More

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Salmonella Typhi outer membrane protein STIV is a potential candidate for vaccine development against typhoid and paratyphoid fever.

Immunobiology 2019 05 22;224(3):371-382. Epub 2019 Mar 22.

Division of Clinical Medicine, National Institute of Cholera and Enteric Diseases, P-33 Scheme-XM, C.I.T. Road, Beliaghata, Kolkata, 700010, India. Electronic address:

Enteric fever, caused by Salmonella enterica serovars, Typhi (S. Typhi) and Paratyphi (S. Paratyphi) is a major public health challenge for the developing nations. Read More

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Diversity of Salmonella Typhi-responsive CD4 and CD8 T cells before and after Ty21a typhoid vaccination in children and adults.

Int Immunol 2019 04;31(5):315-333

Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.

Typhoid fever is a life-threatening disease caused by the human-restricted pathogen Salmonella enterica serovar Typhi (S. Typhi). The oral live attenuated Ty21a typhoid vaccine protects against this severe disease by eliciting robust, multifunctional cell-mediated immunity (CMI), shown to be associated with protection in wild-type S. Read More

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Attenuated Oral Typhoid Vaccine Ty21a Elicits Lamina Propria and Intra-Epithelial Lymphocyte Tissue-Resident Effector Memory CD8 T Responses in the Human Terminal Ileum.

Front Immunol 2019 14;10:424. Epub 2019 Mar 14.

Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States.

Tissue-resident memory T cells (T) are newly defined memory T cells (T) distinct from circulating T subsets which have the potential to mount rapid protective immune responses at the site of infection. However, very limited information is available regarding the role and contribution of T in vaccine-mediated immune responses in humans at the site of infection. Here, we studied the role and contribution of tissue resident memory T cells (T) located in the terminal ileum (TI) (favored site of infection for . Read More

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Age-Associated Heterogeneity of Ty21a-Induced T Cell Responses to HLA-E Restricted Typhi Antigen Presentation.

Front Immunol 2019 4;10:257. Epub 2019 Mar 4.

Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States.

Human-restricted serovar Typhi (. Typhi) is the causative agent of typhoid fever-a life-threatening disease of great global health significance, particularly in the developing world. Ty21a is an oral live-attenuated vaccine that protects against the development of typhoid disease in part by inducing robust T cell responses, among which multifunctional CD8 cytotoxic T lymphocytes (CTL) play an important role. Read More

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Association between . Typhi-specific memory CD4+ and CD8+ T responses in the terminal ileum mucosa and in peripheral blood elicited by the live oral typhoid vaccine Ty21a in humans.

Hum Vaccin Immunother 2019 2;15(6):1409-1420. Epub 2019 Apr 2.

a Center for Vaccine Development and Global Health , University of Maryland School of Medicine , Baltimore , MD , USA.

CD4+ and CD8+ T subsets are essential components of the adaptive immune system which act in concert at the site of infections to effectively protect against pathogens. Very limited data is available in humans regarding the relationship between CD4+ and CD8+ . Typhi responsive cells in the terminal ileum mucosa (TI) and peripheral blood following Ty21a oral typhoid immunization. Read More

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Nonspecific effects of oral vaccination with live-attenuated Typhi strain Ty21a.

Sci Adv 2019 02 27;5(2):eaau6849. Epub 2019 Feb 27.

Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK.

Epidemiological and immunological evidence suggests that some vaccines can reduce all-cause mortality through nonspecific changes made to innate immune cells. Here, we present the first data to describe the nonspecific immunological impact of oral vaccination with live-attenuated Typhi strain Ty21a. We vaccinated healthy adults with Ty21a and assessed aspects of innate and adaptive immunity over the course of 6 months. Read More

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February 2019

Manipulation of Typhi Gene Expression Impacts Innate Cell Responses in the Human Intestinal Mucosa.

Front Immunol 2018 1;9:2543. Epub 2018 Nov 1.

Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States.

Although immunity induced by typhoid fever is moderated and short-lived, typhoid vaccination with the attenuated Ty21a oral vaccine generates long-lasting protection rates reaching up to 92%. Thus, there are important differences on how wild-type and typhoid vaccine strains stimulate host immunity. We hypothesize that vaccine strains with different mutations might affect gut inflammation and intestinal permeability by different mechanisms. Read More

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September 2019

Current Clinical Trials in Non-muscle Invasive Bladder Cancer.

Curr Urol Rep 2018 Oct 24;19(12):101. Epub 2018 Oct 24.

Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, Level 6, 2775 Laurel St, Vancouver, BC, V6N 2W6, Canada.

Purpose Of Review: As our molecular understanding of bladder cancer continues to advance, more and more novel agents are entering clinical trials across the spectrum of bladder cancer stages. The clinical trial activity for non-muscle invasive bladder cancer (NMIBC) has been boosted further by the evolution of specific disease states that set more uniform inclusion criteria for clinical trial design. Here, we aimed to review the current clinical trials landscape in non-muscle invasive bladder cancer with respect to these disease states. Read More

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October 2018

Effect of the live oral attenuated typhoid vaccine, Ty21a, on systemic and terminal ileum mucosal CD4+ T memory responses in humans.

Int Immunol 2019 02;31(2):101-116

Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.

Our current understanding of CD4+ T-cell-mediated immunity (CMI) elicited by the oral live attenuated typhoid vaccine Ty21a is primarily derived from studies using peripheral blood. Very limited data are available in humans regarding mucosal immunity (especially CD4+ T) at the site of infection (e.g. Read More

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February 2019

The Impact of Vaccination and Prior Exposure on Stool Shedding of Salmonella Typhi and Salmonella Paratyphi in 6 Controlled Human Infection Studies.

Clin Infect Dis 2019 04;68(8):1265-1273

Oxford Vaccine Group, Department of Paediatrics, University of Oxford.

Background: Shedding of Salmonella Typhi or Paratyphi in the stool or urine leads to contamination of food or water, which is a prerequisite for transmission of enteric fever. Currently, there are limited data on the effect of vaccination or prior exposure on stool shedding.

Methods: Six Salmonella Typhi or Paratyphi human challenge studies were conducted between 2011 and 2017. Read More

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Longevity of duodenal and peripheral T-cell and humoral responses to live-attenuated Salmonella Typhi strain Ty21a.

Vaccine 2018 07 27;36(31):4725-4733. Epub 2018 Jun 27.

Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, Queen Elizabeth Central Hospital, Malawi. Electronic address:

Background: We have previously demonstrated that polyfunctional Ty21a-responsive CD4 and CD8 T cells are generated at the duodenal mucosa 18 days following vaccination with live-attenuated S. Typhi (Ty21a). The longevity of cellular responses has been assessed in peripheral blood, but persistence of duodenal responses is unknown. Read More

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Vaccines for preventing typhoid fever.

Cochrane Database Syst Rev 2018 05 31;5:CD001261. Epub 2018 May 31.

Cochrane Infectious Diseases Group, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK, L3 5QA.

Background: Typhoid fever and paratyphoid fever continue to be important causes of illness and death, particularly among children and adolescents in south-central and southeast Asia. Two typhoid vaccines are widely available, Ty21a (oral) and Vi polysaccharide (parenteral). Newer typhoid conjugate vaccines are at varying stages of development and use. Read More

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Typhi Bactericidal Antibodies Reduce Disease Severity but Do Not Protect against Typhoid Fever in a Controlled Human Infection Model.

Front Immunol 2017 17;8:1916. Epub 2018 Jan 17.

Oxford Vaccine Group, Department of Paediatrics, University of Oxford, The NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom.

Effective vaccines against , a major cause of febrile illness in tropical regions, can have a significant effect as a disease control measure. Earlier work has shown that immunization with either of two Typhi vaccines, licensed Ty21a or candidate M01ZH09, did not provide full immunity in a controlled human infection model. Here, we describe the human humoral immune responses to these oral vaccines and their functional role in protection after challenge with . Read More

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January 2018

Protection against inhalation anthrax by immunization with Ty21a stably producing protective antigen of .

NPJ Vaccines 2017 15;2:17. Epub 2017 Jun 15.

Protein Potential LLC, Rockville, MD 20850 USA.

The national blueprint for biodefense concluded that the United States is underprepared for biological threats. The licensed anthrax vaccine absorbed vaccine, BioThrax, requires administration of at least 3-5 intramuscular doses. The anthrax vaccine absorbed vaccine consists of complex cell-free culture filtrates of a toxigenic strain and causes tenderness at the injection site and significant adverse events. Read More

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In vivo tropism of Salmonella Typhi toxin to cells expressing a multiantennal glycan receptor.

Nat Microbiol 2018 02 4;3(2):155-163. Epub 2017 Dec 4.

Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.

Typhoid fever is a life-threatening disease, but little is known about the molecular bases for its unique clinical presentation. Typhoid toxin, a unique virulence factor of Salmonella Typhi (the cause of typhoid fever), recapitulates in an animal model many symptoms of typhoid fever. Typhoid toxin binding to its glycan receptor Neu5Ac is central, but, due to the ubiquity of Neu5Ac, how typhoid toxin causes specific symptoms remains elusive. Read More

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February 2018

Induction of Cell Cycle and NK Cell Responses by Live-Attenuated Oral Vaccines against Typhoid Fever.

Front Immunol 2017 12;8:1276. Epub 2017 Oct 12.

Oxford Vaccine Group, Department of Paediatrics, University of Oxford, NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom.

The mechanisms by which oral, live-attenuated vaccines protect against typhoid fever are poorly understood. Here, we analyze transcriptional responses after vaccination with Ty21a or vaccine candidate, M01ZH09. Alterations in response profiles were related to vaccine-induced immune responses and subsequent outcome after wild-type Typhi challenge. Read More

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October 2017

Systemic and Terminal Ileum Mucosal Immunity Elicited by Oral Immunization With the Ty21a Typhoid Vaccine in Humans.

Cell Mol Gastroenterol Hepatol 2017 Nov 16;4(3):419-437. Epub 2017 Aug 16.

Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland.

Background & Aims: Systemic cellular immunity elicited by the Ty21a oral typhoid vaccine has been extensively characterized. However, very limited data are available in humans regarding mucosal immunity at the site of infection (terminal ileum [TI]). Here we investigated the host immunity elicited by Ty21a immunization on terminal ileum-lamina propria mononuclear cells (LPMC) and peripheral blood in volunteers undergoing routine colonoscopy. Read More

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November 2017

Use of a novel antigen expressing system to study the Salmonella enterica serovar Typhi protein recognition by T cells.

PLoS Negl Trop Dis 2017 Sep 5;11(9):e0005912. Epub 2017 Sep 5.

Center for Vaccine Development (CVD), Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, United States of America.

Salmonella enterica serovar Typhi (S. Typhi), the causative agent of the typhoid fever, is a pathogen of great public health importance. Typhoid vaccines have the potential to be cost-effective measures towards combating this disease, yet the antigens triggering host protective immune responses are largely unknown. Read More

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September 2017

Review of current typhoid fever vaccines, cross-protection against paratyphoid fever, and the European guidelines.

Expert Rev Vaccines 2017 10;16(10):1029-1043

d Department of Clinical Medicine , University of Helsinki , Helsinki , Finland.

Introduction: Typhoid and paratyphoid fever remain a global health problem, which - in non-endemic countries - are mainly seen in travelers, particularly in VFRs (visiting friends and relatives), with occasional local outbreaks occurring. A rise in anti-microbial resistance emphasizes the role of preventive measures, especially vaccinations against typhoid and paratyphoid fever for travelers visiting endemic countries. Areas covered: This state-of-the-art review recapitulates the epidemiology and mechanisms of disease of typhoid and paratyphoid fever, depicts the perspective of non-endemic countries and travelers (VFRs), and collectively presents current European recommendations for typhoid fever vaccination. Read More

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October 2017

A novel method to generate Salmonella Typhi Ty21a ghosts exploiting the λ phage holin-endolysin system.

Oncotarget 2017 Jul;8(29):48186-48195

College of Veterinary Medicine, Chonbuk National University, Iksan Campus, Iksan, Republic of Korea.

Human typhoid fever caused by Salmonella Typhi still poses a severe global disease burden in developing countries despite the availability of commercial vaccines. In this study, we constructed a non-living S. Typhi Ty21a vaccine candidate by employing a lambda (λ) phage-derived holin-endolysin system to efficiently construct bacterial ghosts. Read More

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Evolution of Salmonella Typhi outer membrane protein-specific T and B cell responses in humans following oral Ty21a vaccination: A randomized clinical trial.

PLoS One 2017 1;12(6):e0178669. Epub 2017 Jun 1.

Division of Infectious Diseases and Hospital Epidemiology, Kantonsspital St. Gallen, St. Gallen, Switzerland.

Vaccination against complex pathogens such as typhoidal and non-typhoidal Salmonella requires the concerted action of different immune effector mechanisms. Outer membrane proteins (Omps) of Salmonella Typhi are potent immunogens, which elicit long-lasting and protective immunity. Here, we followed the evolution of S. Read More

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September 2017

Overview of the impact of Typhoid and Paratyphoid fever. Utility of Ty21a vaccine (Vivotif®).

J Prev Med Hyg 2017 Mar;58(1):E1-E8

Department of Health Sciences, University of Genoa, Italy.

Cases of diarrhoeal disease number from 1.7 to 5 billion per year worldwide. One of the main causes of diarrhoeal disease is typhoid fever, which is a potentially life-threatening multi-systemic illness. Read More

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A case report of anaphylaxis to Typhoid Vaccine Live Oral Ty21a (Vivotif).

J Travel Med 2017 Sep;24(5)

Emergency Physicians Med Group, 2000 Green Rd, Suite 300, Ann Arbor, MI 48105, USA.

Typhoid Vaccine Live Oral Ty21a (Vivotif) is typically well tolerated, and adverse events are infrequent and mild. To the best of the authors' knowledge, only one prior anaphylactic reaction has previously been reported. We present a case of anaphylaxis related to Vivotif, in which a 66-year-old male with no medical comorbidities developed anaphylaxis following the third of a four-dose course (in the absence of concomitant vaccination administration), which consisted of tongue swelling, difficulty breathing, abdominal discomfort and rash. Read More

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September 2017

A novel approach for construction of an inactivated typhoid vaccine candidate that effectively augments both humoral and cellular immune responses.

Vaccine 2017 06 8;35(25):3333-3341. Epub 2017 May 8.

College of Veterinary Medicine, Chonbuk National University, Iksan Campus, Gobong-ro 79, Iksan 54596, Republic of Korea. Electronic address:

Salmonella enterica serovar Typhi ghost was constructed as a vaccine candidate against typhoid fever. An asd plasmid pJHL187 harboring a ghost cassette comprised of PhiX 174 E lysis gene stringently controlled under the convergent promotor components and was transformed into the asd gene-deleted mutant S. Typhi Ty21a strain (STG). Read More

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