| Autor: |
Tacket, Carol O., Sztein, Marcelo B., Wasserman, Steven S., Losonsky, Genevieve, Kotloff, Karen L., Wyant, Timothy L., Nataro, James P., Edelman, Robert, Perry, Judith, Bedford, Philip, Brown, David, Chatfield, Stephen, Dougan, Gordon, Levine, Myron M. |
| Zdroj: |
Infection and Immunity; March 2000, Vol. 68 Issue: 3 p1196-1201, 6p |
| Abstrakt: |
ABSTRACTSalmonella entericaserovar Typhi strain CVD 908-htrAis a live attenuated strain which may be useful as an improved oral typhoid vaccine and as a vector for cloned genes of other pathogens. We conducted a phase 2 trial in which 80 healthy adults received one of two dosage levels of CVD 908-htrAin a double-blind, placebo-controlled, crossover study. There were no differences in the rates of side effects among volunteers who received high-dose vaccine (4.5 × 108CFU), lower-dose vaccine (5 × 107CFU), or placebo in the 21 days after vaccination, although recipients of high-dose vaccine (8%) had more frequent diarrhea than placebo recipients (0%) in the first 7 days. Seventy-seven percent and 46% of recipients of high- and lower-dose vaccines, respectively, briefly excreted vaccine organisms in their stools. All blood cultures were negative. Antibody-secreting cells producing antilipopolysaccharide (LPS) immunoglobulin A (IgA) were detected in 100 and 92% of recipients of high- and lower-dose vaccines, respectively. Almost half the volunteers developed serum anti-LPS IgG. Lymphocyte proliferation and gamma interferon production against serovar Typhi antigens occurred in a significant proportion of vaccinees. This phase 2 study supports the further development of CVD 908-htrAas a single-dose vaccine against typhoid fever and as a possible live vector for oral delivery of other vaccine antigens. |
| Databáze: |
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