• Vaccine Name: SARS-CoV-2 Vaccine YF-S0
• Target Pathogen: SARS-CoV-2
• Target Disease: COVID-19
• Type: Live, attenuated vaccine
• Status: Research
• Host Species for Licensed Use: None
• Host Species as Laboratory Animal Model: Hamster
• Antigen: S protein of SARS-CoV-2 (Sanchez-Felipe et al., 2021)
• spike (S) protein gene engineering:
  • Type: Recombinant vector construction
  • Description: (Sanchez-Felipe et al., 2021)
  • Detailed Gene Information: Click Here.
• Preparation: Using an advanced reverse genetics system, a panel of YF17D-based candidate vaccines (YF-S) that express the S protein of SARS-CoV-2 in its noncleavable S0 version was generated.
• Immunization Route: Intraperitoneal injection (i.p.)
• Description: A single-dose live-attenuated YF17D-vectored SARS-CoV-2 vaccine protects hamsters against SARS-CoV-2 challenge. (Sanchez-Felipe et al., 2021)

Hamster Response

• Vaccination Protocol: Hamsters were vaccinated at day 0 with a low dose of 10^3 PFU (via the intraperitoneal route) of the different constructs or YF17D and sham (as negative controls), and boosted after 7 days. (Sanchez-Felipe et al., 2021)
• Immune Response: At day 21, all hamsters vaccinated with YF-S1/2 and YF-S0 had seroconverted to high levels of S-specific IgG and virus NAbs with log10-transformed geometric mean titres for YF-S0 of 3.5 (95% confidence interval of 3.3–3.8) for IgG and 2.2 (95% confidence interval of 1.9–2.6) for NAbs, with rapid seroconversion kinetics. (Sanchez-Felipe et al., 2021)
• Challenge Protocol: After 23 or 28 days, hamsters were challenged intranasally with 2 × 10^5 PFU of SARS-CoV-2. (Sanchez-Felipe et al., 2021)
• Efficacy: Four days after infection, we detected high viral loads in the lungs of sham-vaccinated controls and hamsters vaccinated with YF17D as a matched placebo. Hamsters vaccinated with YF-S0 were protected against this aggressive challenge, with a median reduction of 5 log10-transformed viral RNA loads (interquartile range (IQR) of 4.5–5.4) in viral RNA loads, and of 5.3 log10-transformed virus titre (IQR of 3.9–6.3) for infectious virus in the lungs as compared to sham. (Sanchez-Felipe et al., 2021)