A new candidate vaccine for human brucellosis based on influenza viral vectors: a preliminary investigation for the development of an immunization schedule in a guinea pig model

Table 1 Degree of protective efficacy of the vaccines by different routes of administration in guinea pigs

Vaccine	Route of administration	Log₁₀ CFU/animal^a (mean ± SE)	Log₁₀ protection ^b	Value (P) ^c
Influenza viral vector based brucellosis vaccine candidate	c	0.56 ± 0.22	2.3	< 0.003
	i.n	0.06 ± 0.04	2.8	< 0.0001
	s.l	1.22 ± 0.29	1.64	< 0.02
Commercial vaccine B. melitensis Rev.1	s.c	0.48 ± 0.18	0.38	< 0.0005
Control (PBS)	i.n	2.86 ± 0.19	0.00	-

^aDegree of protective efficacy of the vaccines was evaluated by the isolation rate of Brucella from organs and tissues of guinea pigs challenged with the virulent strain of B. melitensis 16 M infection
^bLog₁₀ protection units were obtained by subtracting the mean log₁₀ CFU of the control (PBS) group from the mean of log₁₀ CFU for the experimental group
^cCompared with control group (PBS)
CFU colony forming units, PBS phosphate-buffered saline, c. conjunctivally, i.n. intranasally, s.l. sublingually
Protective efficacy of vaccines as evaluated by the isolation rate of Brucella from the tissues of control and experimental groups of guinea pigs on day 30 after challenging with the virulent strain of B. melitensis 16 M. Animals were vaccinated with the vector vaccine by prime-boost c., i.n., s.l. at interval of 21 days, and with B. melitensis Rev.1 by single s.c. vaccination. Guinea pigs in negative control group were injected with PBS. The challenge of animals was performed with B. melitensis 16 M at a dose of 1.3 log₁₀ CFU/animal using s.c. route.Statistical analysis was performed using two-way ANOVA followed by Tukey’s multiple comparisons test

ISSN: 2049-9957