title: Comparative efficacy of a Coxiella burnetii chloroform:methanol residue (CMR) vaccine and a licensed cellular vaccine (Q-Vax) in rodents challenged by aerosol.
abstract: Q fever is an acute and self-limited febrile illness caused by the obligate intracellular bacterium Coxiella burnetii. While phase I cellular Q fever vaccines are efficacious in humans, vaccination of immune individuals may result in sterile abscesses and granulomas. The chloroform:methanol residue vaccine (CMR) was developed as a safer alternative. The efficacy of a licensed phase I cellular vaccine (Q-Vax) was compared with that of CMR vaccine in A/J mice and Hartley guinea pigs challenged with virulent phase I C. burnetii by aerosol. Both vaccines were efficacious. The CMR vaccine dose required to protect 50% of mice (PD50) against lethal aerosol challenge (11 LD50) was one-third of the Q-Vax dose. However, the PD50 for CMR was four times the Q-Vax dose in guinea pigs challenged by aerosol (60 LD50). It was concluded that CMR is an efficacious alternative to cellular Q fever vaccines for the prevention of Q fever.
authors.affiliation: United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, MD 21702-5011, USA.
authors.forename: D M
authors.initials: DM
authors.lastname: Waag
authors.forename: M J
authors.initials: MJ
authors.lastname: England
authors.forename: M L
authors.initials: ML
authors.lastname: Pitt
mesh_terms: D000336:Aerosols; D000818:Animals; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000627:therapeutic use*; D002725:Chloroform / Q000737:chemistry; D016997:Coxiella burnetii / Q000276:immunology*; D004195:Disease Models, Animal; D005260:Female; D006168:Guinea Pigs; D008297:Male; D000432:Methanol / Q000737:chemistry; D051379:Mice; D008805:Mice, Inbred A; D011778:Q Fever / Q000517:prevention & control*
chemical_list: D000336:Aerosols; D001428:Bacterial Vaccines; D002725:Chloroform; D000432:Methanol