• Vaccine Ontology ID: VO_0004361
• Type: DNA vaccine
• Status: Research
• Host Species as Laboratory Animal Model: Macaque
• VP1 gene engineering:
  • Type: DNA vaccine construction
  • Description: Vector pIRES expressed major structural protein (capsid protein VP1) VP1 of coxsackievirus B3 (CVB3) (Henke et al., 2004).
  • Detailed Gene Information: Click Here.
• Vector: pIRES (Henke et al., 2004)
• Immunization Route: Intramuscular injection (i.m.)

• Type: Inactivated or "killed" vaccine
• Status: Research
• Host Species for Licensed Use: None
• Antigen: Coxsackievirus A5 (Jin et al., 2021)
• Preparation: In an outbreak of HFMD in Xiangyang, China, in 2017, rectal swabs from patients were obtained. CV-A5-3487 was isolated in both RD and Vero cells and grown to titers higher than 1 × 10^8 50% cell culture infectious doses (CCID50)/ml. A Vero cell isolate, CV-A5-vN20, was selected as a vaccine candidate. Vero cells in a 10-layer cell factory were infected with CV-A5-vN20 at a multiplicity of infection (MOI) of 0.001. The harvest was purified through two steps of ultracentrifugation. (Jin et al., 2021)
• Immunization Route: Intraperitoneal injection (i.p.)
• Description: Vero cell-adapted CV-A5 strain is a promising vaccine candidate and could be used as a multivalent HFMD vaccine component in the future. (Jin et al., 2021)

Mouse Response

• Vaccine Immune Response Type: VO_0000286
• Efficacy: DNA immunizations with the major structural protein VP1 of coxsackievirus B3 (CVB3) have been previously found to protect mice from a lethal challenge with CVB3. Co-expression of the immune-stimulatory interleukin-2 (IL-2) can increase the efficacy of the inoculated DNA vaccine depending on the route of administration and the mouse strain used. After i.m. administration, IL-2 co-expression increased the protection rate by 18.3% whereby the g.g. inoculation was much less effective in BALB/c mice. In contrast, after g.g. inoculation IL-2 co-expression increased the protection rate by 36.7% whereby the i.m. was much less effective in C57BL/6 mice (Henke et al., 2004).

Mouse Response

• Vaccination Protocol: A group of 3-day-old mice were primed and boosted on day 10 through the i.p. route (Jin et al., 2021)
• Immune Response: Levels of NtAb titers in sera on days 0, 14, and 28 were determined, representing those of preimmunization, postboost, and postchallenge antisera. In suckling mice, NtAbs were detectable only after boosting (day 14), and the seroconversion rate was 100%. NtAb titers increased dramatically after challenge (day 28, P < 0.001), reflecting strong immune responses following challenge. The results demonstrated that NtAb levels correlated with the survival of immunized mice, and there were no differences in titers of different antigen groups. (Jin et al., 2021)
• Challenge Protocol: A group of 3-day-old mice were challenged 4 days later (once antibody levels had increased) with CV-A5-M14 at a dose of 10 LD50 (2 × 10^6 CCID50/mouse). (Jin et al., 2021)
• Efficacy: All mice in the immunized groups survived after 14 days of observation, showing 100% protection, while all mice in the mock-immunized group died at 6 days postchallenge. (Jin et al., 2021)