Mf. Barile et al., PROTECTION OF IMMUNIZED AND PREVIOUSLY INFECTED CHIMPANZEES CHALLENGED WITH MYCOPLASMA-PNEUMONIAE, Vaccine, 12(8), 1994, pp. 707-714
Following immunization, peak geometric mean serum metabolism inhibitio
n antibody (MIT) titres were 1.13 and 1.16 for groups of three chimpan
zees each that received either the formalin-inactivated OSU-1A or expe
rimental acellular extract vaccine, respectively. Following challenge,
the mean titres for chimpanzees given the acellular vaccine peaked at
1:256 in 4 weeks and was 1.48 at 10 weeks. Chimpanzees given the OSU-
1A vaccine peaked at 1.80 in 4 weeks and remained at 1:80 at 10 weeks.
There was no direct correlation between the serum MIT response and th
e severity of disease or colonization, and thus the MIT response was n
ot a reliable measurement of protection. The two non-immunized chimpan
zees showed significant signs of disease, including cough, pharyngitis
, rhinitis, fever and abnormal X-ray findings, for about 5 weeks. The
chimpanzees immunized with either vaccine were less colonized and show
ed far less disease than non-immunized controls. Protection afforded t
he chimpanzees was similar to that of vaccinees in the human clinical
trial given the same OSU-1A vaccine (Wenzel et al., 1977). The two pre
viously infected chimpanzees were most protected against colonization
and disease on challenge.