BACKGROUND:Escherichia coli O157:H7 causes severe enteritis and hemolytic-uremic syndrome, mostly in young children and older adults. Similar to the case with Shigella, serum IgG against the O-specific polysaccharide of E. coli O157:H7 may confer immunity by lysing the inoculum in the intestine. A phase 1 trial in adults showed that a vaccine of E. coli O157:H7 O-specific polysaccharide conjugated to recombinant exotoxin A of Pseudomonas aeruginosa (O157-rEPA) was safe and immunogenic. METHODS: A phase 2 trial of the O157-rEPA vaccine was conducted in 49 children 2-5 years old who were divided randomly into groups receiving 1 or 2 doses of vaccine. Adverse reactions were monitored. Serum IgG lipopolysaccharide (LPS) antibodies were determined. RESULTS: No significant adverse reactions were observed. At 1 week after the first dose was administered, most children (81%) responded with a >4-fold increase in serum IgG LPS antibodies. At 6 weeks after the first dose was administered, all children responded with a >8-fold increase; a second dose did not elicit a booster response. At 26 weeks after the first dose was administered, the geometric mean titer of serum IgG LPS antibodies was ~20-fold higher than was the prevaccination titer. These serum samples had high titers of bactericidal activity that were correlated roughly with serum IgG LPS antibody titers (r = .78). CONCLUSIONS: The O157-rEPA vaccine was safe and immunogenic in young children. A phase 3 trial of the administration of this conjugate vaccine concurrently with routine immunization in infants is planned.
RCT Entities:
BACKGROUND:Escherichia coli O157:H7 causes severe enteritis and hemolytic-uremic syndrome, mostly in young children and older adults. Similar to the case with Shigella, serum IgG against the O-specific polysaccharide of E. coli O157:H7 may confer immunity by lysing the inoculum in the intestine. A phase 1 trial in adults showed that a vaccine of E. coli O157:H7O-specific polysaccharide conjugated to recombinant exotoxin A of Pseudomonas aeruginosa (O157-rEPA) was safe and immunogenic. METHODS: A phase 2 trial of the O157-rEPA vaccine was conducted in 49 children 2-5 years old who were divided randomly into groups receiving 1 or 2 doses of vaccine. Adverse reactions were monitored. Serum IgG lipopolysaccharide (LPS) antibodies were determined. RESULTS: No significant adverse reactions were observed. At 1 week after the first dose was administered, most children (81%) responded with a >4-fold increase in serum IgG LPS antibodies. At 6 weeks after the first dose was administered, all children responded with a >8-fold increase; a second dose did not elicit a booster response. At 26 weeks after the first dose was administered, the geometric mean titer of serum IgG LPS antibodies was ~20-fold higher than was the prevaccination titer. These serum samples had high titers of bactericidal activity that were correlated roughly with serum IgG LPS antibody titers (r = .78). CONCLUSIONS: The O157-rEPA vaccine was safe and immunogenic in young children. A phase 3 trial of the administration of this conjugate vaccine concurrently with routine immunization in infants is planned.
Authors: Miguel O'Ryan; Roberto Vidal; Felipe del Canto; Juan Carlos Salazar; David Montero Journal: Hum Vaccin Immunother Date: 2015 Impact factor: 3.452
Authors: Marina L Gening; Tomás Maira-Litrán; Andrea Kropec; David Skurnik; Martha Grout; Yury E Tsvetkov; Nikolay E Nifantiev; Gerald B Pier Journal: Infect Immun Date: 2009-11-30 Impact factor: 3.441
Authors: Daniel T Leung; Taher Uddin; Peng Xu; Amena Aktar; Russell A Johnson; Mohammad Arif Rahman; Mohammad Murshid Alam; Meagan Kelly Bufano; Grace Eckhoff; Ying Wu-Freeman; Yanan Yu; Tania Sultana; Farhana Khanam; Amit Saha; Fahima Chowdhury; Ashraf I Khan; Richelle C Charles; Regina C Larocque; Jason B Harris; Stephen B Calderwood; Pavol Kovác; Firdausi Qadri; Edward T Ryan Journal: Clin Vaccine Immunol Date: 2013-03-20