Abstract

Rabies remains an important public health problem in the world due to uncontrolled enzootic rabies, lack of safe efficient vaccines and poor information on the risk of contracting rabies post animal exposure. The lethality and mutagenic potential of challenge virus standard (CVS) was evaluated in mice. Mice were intracerebrally infected (MIC) with low, medium and high viral LD₅₀ (MICLD₅₀). Mice were subjected to immunomodulation using interferon (IFNα-2a) pre- infection. The infected groups pretreated with IFN-α 2a showed a higher survival rate than the infected group. Statistically significant increase in structural and numerical chromosomal aberrations and a decreased mitotic activity of mice bone marrow cells was observed post infection. Pretreatment of the infected groups with IFNα-2a showed a marked and significant reduction of these cytogenetic changes. The increased survival rate and reduced cytogenetic changes suggest that protection induced by interferon against rabies virus activity could be, at least partially, attributable to blockage of the replication of CVS strain of rabies virus. It could be concluded that interferon can be used as an immune enhancer to the application of vaccine administration.

Key words: Rabies, interferon, chromosomal aberration.

Abbreviation

Abbreviations: RV, Rabies virus; IFN, interferon; CA, chro-mosomal aberrations;CVS, challenge virus standard; HrIFN-α2a, Human Interferon alpha-2a; I/P,intraperitoneally; CP, cyclophosphamide; FCS, fetal calf serum; PCEs,polychromatic erythrocytes; NCEs, normochromatic erythrocytes; MN,micronuclei;  DPI, day post infection; PCE%, polychromatic erythrocytes percentage; MNPCEs‰, micronucleated poly-chromatic erythrocytes per thousand; MNNCEs ‰, micronuclei in normochromatic erythrocytes per thousand.