Micro-Neutralization CPE-based (MN-CPE) assay

The cytopathic effect (CPE)–based microneutralization assay is a widely applied functional method for characterizing neutralizing antibody responses elicited by vaccination, or natural infection caused by cytopathogenic viruses. The assay is suitable for the evaluation of immune responses induced by diverse vaccine platforms, including mRNA, viral vector, inactivated, live‑attenuated, and recombinant technologies, and is commonly included as a key endpoint in vaccine immunogenicity programs. The method is based on the capacity of serum antibodies to block viral replication in permissive cell cultures. In practice, heat‑inactivated serum samples are serially diluted and incubated with a defined amount of infectious virus prior to addition to susceptible cell monolayers. After an appropriate incubation period, cultures are examined for virus‑induced cytopathic changes. Neutralizing activity is quantified as the reciprocal of the highest serum dilution that fully prevents the appearance of cytopathic effect. VisMederi perform the assay readout either by direct evaluation of CPE using optical microscopy or by measuring optical density through a colorimetric reaction. The assay is widely applied in VisMederi for evaluation of vaccines and monoclonals against as SARS‑CoV‑2 (Evaluation of SARS-CoV-2 neutralizing antibodies using a CPE-based colorimetric live virus micro-neutralization assay in human serum samples , Immune response to SARS-CoV-2 Omicron variant in patients and vaccinees following homologous and heterologous vaccinations , Extremely potent human monoclonal antibodies from COVID-19 convalescent patients), influenza A and B viruses (A colorimetric readout based on the PrestoBlue® dye as an objective method for measuring neutralizing antibodies against influenza virus in human serum samples , Comparison of influenza-specific neutralizing antibody titers determined using different assay readouts and hemagglutination inhibition titers: good correlation but poor agreement ), Monkeypox and Vaccinia viruses (Evaluation of Monkeypox- and Vaccinia virus-neutralizing antibodies in human serum samples after vaccination and natural infection ; Evaluation of monkeypox- and vaccinia-virus neutralizing antibodies before and after smallpox vaccination: A sero-epidemiological study), parainfluenza viruses, Dengue, Zika, Yellow fever, West Nile, Oropouche, Rift Valley Fever and Chikungunya viruses.