Comparative Immunogenicity and Neutralization Potency of Four Approved COVID-19 Vaccines in BALB/c Mice.

Publication date: Mar 04, 2024

Since the outbreak of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), several vaccine candidates have been developed within a short period of time. Although the potency of these vaccines was evaluated individually, their comparative potency was not comprehensively evaluated. To compare the immunogenicity and neutralization efficacy of four approved COVID-19 vaccines in Iran, including: PastoCovac Plus, Sinopharm, SpikoGen, and Noora in BALB/c mice. Different groups of female BALB/c mice were vaccinated with three doses of each vaccine. The serum levels of antibodies against the viral receptor binding domain (anti-RBD) and spike (anti-spike) protein as well as the vaccine formulation (anti-vaccine) were evaluated using enzyme-linked immunosorbent assay (ELISA). The neutralization efficacy of these four vaccines was assessed through four neutralization assays: conventional virus neutralization test (cVNT), pseudotype virus neutralization test (pVNT), surrogate virus neutralization test (sVNT), and inhibition flow cytometry. All four vaccines induced seroconversion in vaccinated animals. All vaccines successfully induced high levels of anti-vaccine antibody; however, PastoCovac Plus and Sinopharm vaccines induced significantly higher levels of anti-RBD antibody titer compared to Noora and SpikoGen. Moreover, the results of the antibody response were corroborated by the virus neutralization tests, which revealed very weak neutralization potency by Noora and SpikoGen in all tests. Our results indicate significant immunogenicity and neutralization efficacy induced by PastoCovac Plus and Sinopharm, but not by Noora and SpikoGen. This suggests the need for additional comparative assessment of the potency and efficacy of these four vaccines in vaccinated subjects.

Concepts Keywords
Elisa COVID-19
Iran Immunogenicity
Mice Neutralization
Severe SARS-CoV-2
Vaccine Vaccine


Type Source Name
disease MESH COVID-19
disease VO Severe acute respiratory syndrome coronavirus 2
disease VO vaccine
disease VO time
disease VO Noora
disease VO vaccinated
disease IDO assay
disease MESH seroconversion
disease VO antibody titer

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