Safety, Immunogenicity and Efficacy of Shigella Conjugate Vaccines in 1-4 Year Olds in Israel

Shigellosis Clinical Trial

Official title:

Phase 3 Study (Safety, Immunogenicity and Efficacy) of Improved Shigella Conjugate Vaccines in 1-4 Year Olds in Israel

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00368316
• Other study ID #: 999900003
• Secondary ID: OH00-CH-N003
• Status: Completed
• Phase: Phase 3
• First received: August 22, 2006
• Last updated: June 21, 2012
• Start date: January 2003
• Est. completion date: February 2009

Study information

• Verified date: June 2012
• Source: National Institutes of Health Clinical Center (CC)
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Food and Drug Administration
• Study type: Interventional

Clinical Trial Summary

Shigellosis remains a serious and frequent disease throughout the world. Development of vaccines has been difficult because shigellae are habitants of and pathogens for humans only and there is no consensus about the mechanism(s) of immunity to this pathogen.

Incomplete, but compelling evidence, indicates that a critical level of serum IgG anti-LPS confers immunity to shigellosis. Important data come from our clinical trial in the Israel Defense Forces (IDF) recruits. A randomized, double-blind, vaccine-controlled study showed that the S. sonnei-rEPA elicited 74% protection against shigellosis occurring about 3 months after vaccination (p=0.001). This vaccine conferred 43% (p=0.04) protection in one company during an outbreak up to 14 days following vaccination suggesting that our Shigella conjugates might be of value in epidemics. The efficacy of S. sonnei-rEPA was correlated with the level of vaccine-induced IgG antibodies.

The highest incidence, morbidity, and mortality of shigellosis is in young children. But serum antibody responsiveness to polysaccharide-based vaccines is age-dependent and infants and young children respond poorly or not at all to both disease and vaccination. The safety and immunogenicity of these Shigella conjugates in 4 to 6 years-old children in Israel was demonstrated. But although the fold rise in anti-LPS was similar in the children, the level of anti-LPS elicited by the conjugates was lower than in adults. We improved the immunogenicity of Shigella conjugates as shown in mice and then in adult humans. Now we apply to evaluate the safety, immunogenicity and efficacy of these improved conjugates in 1 to 4 years-old children in Israel.

In Israel, shigellosis is common especially in children. S. sonnei (Group D) comprise about 60% of the isolates followed by S. flexneri (Group B): Shigella dysenteriae type 1 (Group A) is not found. We propose to administer 2 injections of either S. sonnei-CRM9 or S. flexneri type 2a-rEPAsucc 6 weeks apart in a random double-blind fashion to about 6,000 1 to 4 year-olds. Active surveillance of the vaccinees for enteric infections will be maintained for at least 2 years to evaluate the effect of vaccination.

Description:

Shigellosis remains a serious and frequent disease throughout the world. Development of vaccines has been difficult because shigellae are habitants of and pathogens for humans only and there is no consensus about the mechanism/s of immunity to this pathogen.

Incomplete, but compelling evidence, indicates that a critical level of serum IgG anti-LPS confers immunity to shigellosis. A randomized, double-blind, vaccine-controlled study in Israel Defense Force (IDF) recruits showed that the S. sonnei-rEPA elicited 74% protection against shigellosis occurring about 3 months after vaccination (p=0.001). This vaccine also conferred 43% (p=0.04) protection in one company during an outbreak up to 17 days following vaccination suggesting that our Shigella conjugates might be of value in epidemics. The efficacy of S. sonnei-rEPA was correlated with the level of vaccine-induced IgG antibodies.

The highest incidence, morbidity, and mortality of shigellosis is in young children. But serum antibody responsiveness to it is age dependent and infants and young children respond poorly or not at all to polysaccharide antigens following disease, administration of attenuated strains of Shigella or vaccination with whole cell vaccines. The safety and immunogenicity of similar Shigella conjugates in 4 to 7 years-old children in Israel was demonstrated. But, although the fold rise in anti-LPS was similar in the children, the level of anti-LPS elicited by the conjugates was lower than in adults. We improved the immunogenicity of Shigella conjugates as shown in mice and then in adult humans. Now we apply to evaluate the safety, immunogenicity and efficacy of these improved conjugates in 1 to 4 years-old children in Israel. In addition to monitoring the safety and immunogenicity of the two investigational Shigella vaccines, active surveillance of the vaccines for enteric infections wil be maintained for at lest 2 years to evaluate the effect of vaccination.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 2799
• Est. completion date: February 2009
• Est. primary completion date: January 2008
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 1 Year to 4 Years

Eligibility

• INCLUSION CRITERIA:

Volunteers who are healthy 1-4 year old children whose parents/guardians have read the Information Sheet provided by the Principal Investigator and signed the consent form, and who will be available for follow up.

EXCLUSION CRITERIA: Children with

• chronic diseases receiving medication;

• who have received systemic steroids during the month preceding Shigella vaccination;

• who had severe side effects following vaccinations; and

• those not available for follow up.

Study Design

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Prevention

Related Conditions & MeSH terms

• Shigellosis

Intervention

Biological:
• Shigella conjugate vaccines
Shigella sonnei-rEPA and Shigella flexneri2a rEPA vaccines

Locations

Country	Name	City	State
Israel	Schneider Childrens Hospital	Petach Tikva
Israel	Chaim Sheba Medical Center	Tel Aviv

Sponsors (3)

Lead Sponsor	Collaborator
Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)	Schneider Children's Medical Center, Israel, The Chaim Sheba Medical Center

Country where clinical trial is conducted

Israel, 

References & Publications (7)

Development of vaccines against shigellosis: memorandum from a WHO meeting. Bull World Health Organ. 1987;65(1):17-25. — View Citation

DuPont HL, Hornick RB, Snyder MJ, Libonati JP, Formal SB, Gangarosa EJ. Immunity in shigellosis. II. Protection induced by oral live vaccine or primary infection. J Infect Dis. 1972 Jan;125(1):12-6. — View Citation

Hossain MA, Hasan KZ, Albert MJ. Shigella carriers among non-diarrhoeal children in an endemic area of shigellosis in Bangladesh. Trop Geogr Med. 1994;46(1):40-2. — View Citation

Huilan S, Zhen LG, Mathan MM, Mathew MM, Olarte J, Espejo R, Khin Maung U, Ghafoor MA, Khan MA, Sami Z, et al. Etiology of acute diarrhoea among children in developing countries: a multicentre study in five countries. Bull World Health Organ. 1991;69(5):549-55. — View Citation

Passwell JH, Ashkenzi S, Banet-Levi Y, Ramon-Saraf R, Farzam N, Lerner-Geva L, Even-Nir H, Yerushalmi B, Chu C, Shiloach J, Robbins JB, Schneerson R; Israeli Shigella Study Group. Age-related efficacy of Shigella O-specific polysaccharide conjugates in 1- — View Citation

Struelens MJ, Patte D, Kabir I, Salam A, Nath SK, Butler T. Shigella septicemia: prevalence, presentation, risk factors, and outcome. J Infect Dis. 1985 Oct;152(4):784-90. — View Citation

Taylor DN, Echeverria P, Blaser MJ, Pitarangsi C, Blacklow N, Cross J, Weniger BG. Polymicrobial aetiology of travellers' diarrhoea. Lancet. 1985 Feb 16;1(8425):381-3. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Number of Participants With Adverse Events	Number of participants with events per vaccine type and dose occuring in >=5% of participants	Monitored for 7 days per participant following each injection for initial group of 500, 2 days for extended study of up to 5500 additional children	Yes
Secondary	Geometric Mean Immunoglobulin G (IgG) Anti-Lipopolysaccharide (LPS) Levels	Age-related homologous IgG anti-LPS levels	Injections were administered 6 weeks apart and IgG anti-LPS levels determined >2 weeks after second vaccine dose. Each of the 15 sites also took a sample/week randomly chosen, for 2 years of follow up and blood samples from patients with disease	No
Secondary	Percentage of Efficacy	Percent efficacy is defined as ((disease rate of controls minus disease rate of vaccinees) divided by disease rate of controls) times 100	During 2 years post vaccination	No