Protective immunity against botulism provided by a single dose vaccination with an adenovirus-vectored vaccine.
Botulinum neurotoxins cause botulism, a neuroparalytic disease in humans and animals. We constructed a replication-incompetent adenovirus encoding a synthesized codon-optimized gene for expression of the heavy chain C-fragment (H(C)50) of botulinum neurotoxin type C (BoNT/C). This recombinant human serotype 5 adenoviral vector (Ad5) was evaluated as a genetic vaccine candidate against botulism caused by BoNT/C in a mouse model. A one-time intramuscular injection with 10(5) to 2 x 10(7)pfu of adenoviral vectors elicited robust serum antibody responses against H(C)50 of BoNT/C as assessed by ELISA. Immune sera showed high potency in neutralizing the active BoNT/C in vitro. After a single dose of 2 x 10(7)pfu adenoviral vectors, the animals were completely protected against intraperitoneal challenge with 100 x MLD(50) of active BoNT/C. The protective immunity appeared to be vaccine dose-dependent. The anti-toxin protective immunity could last for at least 7 months without a booster injection. In addition, we observed that pre-existing immunity to the wild-type Ad5 in the host had no significant influence on the protective efficacy of vaccination. The data suggest that an adenovirus-vectored genetic vaccine is a highly efficient prophylaxis candidate against botulism.
Zeng
Mingtao
M
Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Box 672, 601 Elmwood Avenue, Rochester, NY 14642, USA. Mingtao_Zheng@urmc.rochester.edu
Xu
Qingfu
Q
Elias
Md
M
Pichichero
Michael E
ME
Simpson
Lance L
LL
Smith
Leonard A
LA
D000256:Adenoviridae / Q000235:genetics / Q000276:immunology*; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001905:Botulinum Toxins / Q000235:genetics / Q000276:immunology; D001906:Botulism / Q000276:immunology* / Q000517:prevention & control; D004797:Enzyme-Linked Immunosorbent Assay; D005822:Genetic Vectors / Q000008:administration & dosage / Q000235:genetics; D006801:Humans; D051379:Mice; D014611:Vaccination / Q000379:methods
D000907:Antibodies, Bacterial; D001905:Botulinum Toxins