The Need

Part of Thermo Fisher Scientific logo

Companies developing COVID-19 vaccines require a safe and reliable assay to assess the ability of their vaccines to elicit an effective immune response. A common immunogenicity endpoint is the ability of vaccinated patient sera to neutralize SARS-CoV-2 virus. Developers require safe, quantitative, and high-throughput immunogenicity assays to screen hundreds to thousands of samples. PPD, a global contract research organization, is among the companies that have sought an immunogenicity assay to screen patient serum samples during vaccine clinical trials.

The Solution

Integral Molecular’s quality-controlled SARS-CoV-2 Reporter Virus Particles (RVPs) are a safe, critical reagent used by over 100 labs around the world to test virus neutralization by antibodies. RVPs display the SARS-CoV-2 spike protein pseudotyped onto non-replicative lentiviral particles. They provide a rapid and safe (BSL-2) alternative to using live virus for assaying the neutralizing effects of SARS-CoV-2 antibodies produced in response to vaccination.

Serum Neutralization Titers Measured by RVPs
Cultured Cells Expressing GFP Following RVP Infection

The Impact               

Assay Development

We have enabled customers like PPD to develop high-throughput and reliable assays to screen sera and test vaccine efficacy against SARS-CoV-2 and virus variants in accordance with WHO and FDA guidances. PPD used Integral Molecular’s SARS-CoV-2 RVPs to develop their Pseudovirus Microneutralization (MNT) Assay for testing immunogenicity endpoints to support COVID-19 vaccine clinical trials. Details of this assay are published in Bonhomme et al., 2022. The RVP assay met all of PPD’s acceptance criteria for precision, dilutional linearity, selectivity, and specificity. After development of their neutralization assay using Integral Molecular’s RVPs, the authors stated that the assay was “acceptable for use in the assessment of antibody responses in clinical trial samples from Phase I studies and beyond.”

Contact Us