Safety Studies of the Oral Rabies Vaccine SAD B19 in Striped Skunk (Mephitis mephitis)

Abstract

Safety of the modified live rabies virus vaccine, SAD B19, was studied in striped skunks (Mephitis mephitis). Seven skunks received 10(7.9) foci formatting units by direct oral administration. In four cages, a vaccinated animal was placed with a control animal, the other three vaccinated skunks were housed individually. Saliva and nasal swabs were collected 1, 2, 4, 24, 48, and 72 hr post-vaccination. From all vaccinated and control animals (n = 11) blood samples were collected 0, 28, 56, 84, and 296 days post-vaccination. Three of seven vaccinated skunks seroconverted. None of the control animals had detectable levels of rabies virus neutralizing antibodies. Also no vaccine virus was isolated from the nasal and saliva swabs collected from any animal. Thus, SAD B19 was innocuous for skunks in our study after direct oral administration at field concentration.

A replication-deficient rabies virus vaccine expressing Ebola virus glycoprotein is highly attenuated for neurovirulence

“…As RABV is still a considerable public health issue in Africa with an estimated 24,000 deaths reported yearly (Cleaveland et al, 2002;Knobel et al, 2002;Schnell et al, 2010), a bivalent vaccine that confers protection from RABV and EBOV would be an economical and efficient public health tool. However, in addition to the development of inactivated RABV/ EBOV vaccines, the parental recombinant RABV vaccine used to generate the RABV/ EBOV vaccine candidates is derived from the SAD B19 strain, which is used for wildlife vaccination by baiting in Europe suggesting additional applications of our vaccine candidates (Vos et al, 1999;Vos et al, 2002). Therefore, live-attenuated RABV/EBOV vaccines could be considered for use in Africa in an analogous campaign to protect at risk NHPs from lethal EBOV infections.…”

Inactivated or Live-Attenuated Bivalent Vaccines That Confer Protection against Rabies and Ebola Viruses

“…In the case of HIV-1, these RABV vaccine candidates have been characterized by potent induction of humoral and cellular immunity in mice and NHPs and are avirulent after peripheral administration. The RABV vaccine vectors are generated from a reverse genetics system derived from the live-attenuated SAD B19 RABV vaccine, which is used for wildlife vaccination in Europe (49,50). Further attenuated RABV vectored vaccines have been generated by the introduction of mutations in the RABV glycoprotein (G) as well as the deletion of the RABV G; these viruses are propagated on trans-complementing cell lines that express RABV G (17,29,31).…”

Immunogenicity Studies in Carnivores Using a Rabies Virus Construct with a Site-Directed Deletion in the Phosphoprotein

“…The reduced ability of SAD dIND1 to induce rabies VNA compared to the SAD B19 vaccine strain was also shown in skunks. During a previous safety study with SAD B19, 3 of seven skunks receiving10 7.9 FFU by direct oral gavage seroconverted, and all three animals had measurable levels of rabies virus VNA (>5.0 IU/mL) 296 days after vaccination [37]. From this study, it can be concluded that the enhanced IFN production in response to SAD dIND1 results in a strong antiviral effect that outperforms the acknowledged immune-stimulatory effect of type I IFN.…”