Study: NCT05846243

Intervention type: BIOLOGICAL
Group type: EXPERIMENTAL
Intervention: VAC∆6 vaccine (10⁷ PFU)
Description: Live cell-based vaccine against smallpox and other orthopoxvirus infections (VAC∆6 vaccine) based on vaccinia virus (manufactured by FBRI SRC VB Vector, Rospotrebnadzor).~Batch: 08-10.19 (expiry date: 13.10.2021). Dosage: single intradermal dose of 10⁷ PFU/0.2 ml of vaccinia virus.

Intervention type: BIOLOGICAL
Group type: EXPERIMENTAL
Intervention: VAC∆6 vaccine (10⁷ PFU)
Description: Live cell-based vaccine against smallpox and other orthopoxvirus infections (VAC∆6 vaccine) based on vaccinia virus (manufactured by FBRI SRC VB Vector, Rospotrebnadzor).~Batch: 08-10.19 (expiry date: 13.10.2021). Dosage: single intradermal dose of 10⁷ PFU/0.2 ml of vaccinia virus.

Intervention type: BIOLOGICAL
Group type: EXPERIMENTAL
Intervention: VAC∆6 vaccine (10⁷ PFU)
Description: Live cell-based vaccine against smallpox and other orthopoxvirus infections (VAC∆6 vaccine) based on vaccinia virus (manufactured by FBRI SRC VB Vector, Rospotrebnadzor).~Batch: 08-10.19 (expiry date: 13.10.2021). Dosage: single intradermal dose of 10⁷ PFU/0.2 ml of vaccinia virus.

Intervention type: BIOLOGICAL
Group type: EXPERIMENTAL
Intervention: VAC∆6 vaccine (10⁶ PFU)
Description: Live cell-based vaccine against smallpox and other orthopoxvirus infections (VAC∆6 vaccine) based on vaccinia virus (manufactured by FBRI SRC VB Vector, Rospotrebnadzor).~Batch: 08-10.19 (expiry date: 13.10.2021). Dosage: two intradermal doses of 10⁶ PFU/0.2 ml of vaccinia virus (given 28 days apart).

Intervention type: BIOLOGICAL
Group type: EXPERIMENTAL
Intervention: VAC∆6 vaccine (10⁶ PFU)
Description: Live cell-based vaccine against smallpox and other orthopoxvirus infections (VAC∆6 vaccine) based on vaccinia virus (manufactured by FBRI SRC VB Vector, Rospotrebnadzor).~Batch: 08-10.19 (expiry date: 13.10.2021). Dosage: two intradermal doses of 10⁶ PFU/0.2 ml of vaccinia virus (given 28 days apart).

Intervention type: BIOLOGICAL
Group type: EXPERIMENTAL
Intervention: Live Smallpox Vaccine
Description: Live smallpox vaccine (Smallpox vaccine) (manufactured by the Federal State Unitary Enterprise NPO Microgen of the Ministry of Health of Russia).~Batch No. Т30 (expiry date: March, 2021). Dosage: Single 1x10⁶ PFU dose administered by multiple-pricking technique on the 30th/60th day after full series of vaccination with VAC∆6.

Intervention type: BIOLOGICAL
Group type: EXPERIMENTAL
Intervention: Live Smallpox Vaccine
Description: Live smallpox vaccine (Smallpox vaccine) (manufactured by the Federal State Unitary Enterprise NPO Microgen of the Ministry of Health of Russia).~Batch No. Т30 (expiry date: March, 2021). Dosage: Single 1x10⁶ PFU dose administered by multiple-pricking technique on the 30th/60th day after full series of vaccination with VAC∆6.

Intervention type: OTHER
Group type: PLACEBO_COMPARATOR
Intervention: Placebo (Sodium chloride bufus, 0.9%)
Description: Sodium chloride bufus, a 0.9% solvent for the preparation of a dosage form for injections (manufactured by JSC Pharmaceutical manufacturing company Obnovlenie, Russia).~Batch: 391219 (expiry date: January, 2025).

Intervention type: OTHER
Group type: PLACEBO_COMPARATOR
Intervention: Placebo (Sodium chloride bufus, 0.9%)
Description: Sodium chloride bufus, a 0.9% solvent for the preparation of a dosage form for injections (manufactured by JSC Pharmaceutical manufacturing company Obnovlenie, Russia).~Batch: 391219 (expiry date: January, 2025).

Intervention type: OTHER
Group type: PLACEBO_COMPARATOR
Intervention: Placebo (Sodium chloride bufus, 0.9%)
Description: Sodium chloride bufus, a 0.9% solvent for the preparation of a dosage form for injections (manufactured by JSC Pharmaceutical manufacturing company Obnovlenie, Russia).~Batch: 391219 (expiry date: January, 2025).