• Type: Live, attenuated vaccine
• Status: Licensed
• Host Species for Licensed Use: Hamster
• Preparation: MVA-BN YF was prepared by inserting the coding region of preM and E that are based on the naturally occurring sequence of YFV into the MVA-BN backbone.(Julander et al., 2018)
• Immunization Route: Intramuscular injection (i.m.)
• Description: [A MVA-based YF vaccine was tested with and without a non-mineral oil adjuvant in a hamster model of lethal YF disease expressing the poly-protein PreM-E of YFV.(Julander et al., 2018)

• Type: Inactivated or "killed" vaccine
• Status: Licensed
• Host Species for Licensed Use: Human
• Immunization Route: Intramuscular injection (i.m.)
• Description: XRX-001 is an inactivated vaccine candidate based on a β-propriolactone-inactivated virus generated in cell culture. Multiple dose administration is required when administered.(Montalvo et al., 2022)

• Type: Live, attenuated vaccine
• Status: Research
• Host Species for Licensed Use: None
• Host Species as Laboratory Animal Model: hamster
• Antigen: SARS-CoV-2 spike antigen (Ma et al., 2022)
• Vector: YF17D (Ma et al., 2022)
• Preparation: The live-attenuated YF17D vectored SARS-CoV-2 vaccine candidate (YF-S0) expresses the non-cleavable stabilized prefusion form of the SARS-CoV-2 spike antigen as in-frame fusion within the YF17D-E/NS1 intergenic region. (Ma et al., 2022)
• Immunization Route: Intraperitoneal injection (i.p.)
• Description: Live-attenuated YF17D-vectored COVID-19 vaccine protects from lethal yellow fever virus infection in mouse and hamster models. Vaccine induces protection against SARS-Cov-2 and YFV. (Ma et al., 2022)

Mouse Response

• Vaccination Protocol: Ifnar−/− mice were vaccinated intraperitoneally (i.p.) with a single 400 PFU dose of either YF-S0 or YF17D as positive control. Sham groups received a same volume of MEM containing 2% FBS (referred to as medium). (Ma et al., 2022)
• Immune Response: Single YF-S0 vaccination elicited approximately equivalent levels of YFV-specific nAbs (log10-transformed geometric mean titres, log10 GMT 3.7, 95% CI 3.5–3.9) and total IgG (log10 GMT of 5.2, 95% CI 4.8–5.5) as YF17D vaccination (log10 GMT 3.8, 95% CI 3.5–4.1 for nAbs; log10 GMT 5.4, 95% CI 5.1–5.7 for IgG). Moreover, high levels of spike-specific nAbs (log10 GMT 2.3, 95% CI 1.8–2.8) and IgG (log10 GMT 3.3, 95% CI 3.1–3.5) were conjointly induced after a single low YF-S0 dose in mice. (Ma et al., 2022)
• Challenge Protocol: Four weeks post-vaccination, mice were deeply anesthetized by intraperitoneal injection of a mixture of xylazine (16 mg kg−1, XYL-M, V.M.D.), ketamine (40 mg kg−1, Nimatek, EuroVet) and atropine (0.2 mg kg−1, Sterop), and then intracranially injected with 30μl containing 3 × 10^3 PFU YF17D. (Ma et al., 2022)
• Efficacy: All sham-immunized mice experienced acute weight loss and progressed rapidly to severe neurological disease with ruffled fur, hunched posture and hind limb paralysis, uniformly reaching human endpoint as early as five days post infection (dpi), whereas full protection was conferred in mice vaccinated with either YF-S0 or YF17D, as confirmed by the absence of any signs of disease, rapid recovery and weight gain. Data indicate that single YF-S0 vaccination provides full protection against YF17D i.c. challenge as well as YFV-induced inflammatory damage to the liver and other relevant target organs in mice, comparable to original YF17D. (Ma et al., 2022)

Hamster Response

• Vaccination Protocol: Animals were vaccinated s.c. with 1 × 108 TCID50 of MVA-BN-YF, with or without Montanide adjuvant.(Julander et al., 2018)
• Immune Response: There were also significantly (p < 0.05) higher levels of nAb in the serum of animals vaccinated with MVA-BN YF with and without adjuvant when compared with those from animals vaccinated with YF-VAX(Julander et al., 2018)

Hamster Response

• Immune Response: This vaccine candidate conferred protection to hamsters against lethal challenge through passive immunization and resulted in the generation of neutralizing antibody titers in cynomolgus macaques.(Montalvo et al., 2022)

Hamster Response

• Vaccination Protocol: Hamsters were vaccinated i.p. with 10^4 PFU of either YF-S0 or YF17D as positive control at day 0, while sham groups received same volume of medium. (Ma et al., 2022)
• Immune Response: Single dose of YF-S0 induced consistently high levels of YFV-specific nAbs (log10 GMT 2.9, 95% CI 1.9–3.9) and IgG (log10 GMT 3.8, 95% CI 2.6–4.9) in 8 out of 9 vaccinated hamsters (primary vaccine failure in 1/9); comparable to original YF17D regarding IgG and somewhat lower for nAbs (YF17D: log10 GMT 4.2, 95% CI 4.0–4.4 and log10 GMT 4.0, 95% CI 3.8–4.1, respectively). (Ma et al., 2022)
• Challenge Protocol: Three weeks post-vaccination, animals were bled and challenged i.p. with 10^5 PFU of hamster-adapted YFV Asibi virus, a dose that has previously been shown to be 100% lethal in 3-weeks old hamsters. (Ma et al., 2022)
• Efficacy: After challenge, hamsters vaccinated with either YF17D or YF-S0 remained healthy, while sham-immunized animals suffered from clear signs of severe YFV-induced disease such as desiccation, lethargy, growth retardation and weight loss, and had to be euthanized as early as 5 dpi. Results indicate that single-dose YF-S0 vaccination provides full protection against YFV challenge and virus-induced viscerotropic disease in hamsters, comparable to original YF17D. (Ma et al., 2022)