Immunogenicity evaluation of a novel virus-like particle vaccine candidate against SARS-CoV-2 in BALB/c.

Coronavirus disease (COVID-19) pandemic has imposed deployment of an effective vaccine as a worldwide health priority. The new variants of SARS-CoV-2 have also brought serious concerns due to the virus eradiation hesitance. In the study, we evaluated the protective immune system activity of a recombinant viral-vector-based vaccine candidate encoding a fusion spike, membrane and nucleocapsid proteins, Spike (528-1273aa)-M-N, in BALB/c in two different routes of delivery of intranasal and subcutaneous. The immune responses were then assessed through specific SARS-CoV-2 antibodies, interleukin and granzyme B secretion. The outcomes showed that, the IgG titer and IgA secretion was higher in intranasal route in comparison with subcutaneous what is more, a higher titer of IL-4 was detected through intranasal route whereas IFN-γ was highly induced via subcutaneous route. The cytotoxic cell activities were mostly achieved via subcutaneous route immunization. Vaccination with the target antigen is immunogenic and led to specific antibodies induction. Both humoral and cellular immunity arms were well activated in immunized mice, especially through intranasal route with detectable IgA and IgG. Therefore, implication of the platform as a potential vaccine candidate has the potency as a future prophylactic vaccine which guarantees further investigations for the assessment of its immunogenicity in human.