Be. Ivins et al., COMPARATIVE EFFICACY OF EXPERIMENTAL ANTHRAX VACCINE CANDIDATES AGAINST INHALATION ANTHRAX IN RHESUS MACAQUES, Vaccine, 16(11-12), 1998, pp. 1141-1148
Citations number
52
Categorie Soggetti
Veterinary Sciences",Immunology,"Medicine, Research & Experimental
The authors examined the efficacy of Bacillus anthracis protective ant
igen (PA) combined with adjuvants as vaccines against an aerosol chall
enge of virulent anthrax spores in rhesus macaques. Adjuvants tested i
ncluded i) aluminum hydroxide (Alhydrogel), ii) saponin QS-21 and iii)
monophosphoryl lipid A (MPL) in squalene/lecithin/Tween 80 emulsion (
SLT). Animals were immunized once with either 50 mu g of recombinant P
A plus adjuvant, or with Anthrax Vaccine Adsorbed (AVA), the licensed
human anthrax vaccine. The serological response to PA was measured by
enzyme-linked immunosorbent assay. Lymphocyte proliferation and serum
neutralization of in vitro lethal toxin cytotoxicity were also assayed
. In all vaccine groups, anti-PA IgM and IgG titers peaked at 2 weeks
and 4-5 weeks postimmunization, respectively. Five weeks postimmunizat
ion, animals in all vaccine groups demonstrated PA-specific lymphocyte
proliferation and sera that neutralized in vitro cytotoxicity. Six we
eks after immunization, the animals were challenged by aerosol with ap
proximately 93 LD50 of virulent anthrax spores. Animals were bled dail
y for 1 week to monitor bacteremia, and deaths were recorded. Anti-PA
ELISA titers in all groups of immunized animals were substantially inc
reased 2 weeks after challenge. One dose of each vaccine provided sign
ificant protection (> 90%) against inhalation anthrax in the rhesus ma
caques. Published by Elsevier Science Ltd.