• Product Name: PiCoVacc
• Manufacturer: Sinovac Biotech Ltd
• Vaccine Ontology ID: VO_0005142
• Type: Inactivated or "killed" vaccine
• Status: Clinical trial
• Host Species for Licensed Use: Human
• Host Species as Laboratory Animal Model: Mouse, Macaque, Rat
• Antigen: Whole virus (Gao et al., 2020)
• Preparation: The virus was propagated in a 50-liter culture of Vero cells using the Cell Factory system and inactivated by using β-propiolactone The virus was purified using depth filtration and two optimized steps of chromatography, yielding a highly pure preparation of PiCoVacc. (Gao et al., 2020)
• Immunization Route: Intramuscular injection (i.m.)
• Description: A purified inactivated SARS-CoV-2 virus vaccine(Gao et al., 2020)

Mouse Response

• Host Strain: BALB/c mouse
• Vaccination Protocol: Mice were vaccinated at day 0 and 7 with either 1.5 μg/dose, 3.0 μg/dose, or 6.0 μg/dose on both days. (Gao et al., 2020)
• Immune Response: SARS-CoV-2 S- and RBD-specific immunoglobulin G (Ig G) developed quickly in the serum of vaccinated mice and peaked at the titer of 819,200 (>200 μg/ml) and 409,600 (>100 μg/ml), respectively, at week 6(Gao et al., 2020)
• Description: BALB/c mice were injected with vaccine 5761 at days 0 and 7.(Gao et al., 2020)

Rat Response

• Host Strain: Wistar
• Vaccination Protocol: Rats were vaccinated at day 0 and 7 with either 1.5 μg/dose, 3.0 μg/dose, or 6.0 μg/dose on both days.(Gao et al., 2020)
• Immune Response: Immune Response Description: SARS-CoV-2 S- and RBD-specific immunoglobulin G (Ig G) developed quickly in the serum of vaccinated rats and the maximum neutralizing titers reached 2,048-4,096 at week 7 (Gao et al., 2020)

Macaque Response

• Host Strain: Rhesus macaque
• Vaccination Protocol: Macaques were immunized three times via the intramuscular route with medium (3 μg per dose) or high doses (6 μg per dose) of PiCoVacc at day 0, 7 and 14 (n=4)(Gao et al., 2020)
• Immune Response: . S-specific IgG and NAb were induced at week 2 and rose to ~12,800 and ~50, respectively at week 3 after vaccination in both vaccinated groups, whose titers are similar to those of serum from the recovered COVID-19 patients. NAb titer (61) in the medium dose immunized group were ~20% greater than that observed (50) in the high dose vaccinated group at week 3, removing the outlier instead have medium dose group be ~40% lower than that in the high dose group (Gao et al., 2020)
• Side Effects: No serious pathology recorded at day 29 in vaccinated groups (Gao et al., 2020)
• Challenge Protocol: Challenge protocol involved direct inoculation of 1e6 TCID50 of SARS-CoV-2 CN1 into the animal lung through the intratracheal route at day 22 (one week after the third immunization and after immune response results were recorded) (Gao et al., 2020).
• Efficacy: argely protected against SARS-CoV-2 infection with very mild and focal histopathological changes in a few lobes of lung, which probably were caused by a direct inoculation of 106 TCID50 of virus into the lung through intratracheal route, that needed longer time (more than one week) to recover completely (Gao et al., 2020).