Rapid high-throughput neutralisation assays are essential for the analysis of human responses to natural infection and immune responses generated in animal vaccination experiments.

We will establish low-risk PC2-compliant standardised retroviral pseudo-typing assays accessible to a larger number of Australian laboratories (whole virus work is performed in enhanced PC3).

In addition, this approach allows any envelope protein to be used in pseudo-typing allowing antigenic variants emerging in the pandemic to be examined.

We will clone the S open reading frame from alphacoronaviruses (229E and NL63), diverse betacoronaviruses from group A (OC43, KHU1), group B including SARS-CoV-1, and a global panel of SARS-CoV-2 isolates (selected for geographical location and sequence evolution of S using GISAID coronavirus resource) and group C (MERS).

Unrelated viral envelopes will be included as controls from HIV-1, HCV and MLV viruses. The assay, performed in 384 well plates (16 viruses in triplicate, 8-point dilution series) will be measured in a Clariostar fitted with a plate stacker (20 plates) allowing high throughput assessment of Nab (neutralising antibody) responses.

Once established, we will transfer this technology to 360biolabs which will establish protocols and validation under NATA accreditation.

This technology will then be available to Australian and International groups for monitoring immunogenicity in phase I clinical trials of vaccine candidates.

It is anticipated that these assays will have multiple uses including: (i) preclinical evaluation of vaccine candidates using animal serum (ii) evaluation of the NAb response in human clinical trials and (iii) the study of how NAbs develop, and their specificity in natural COVID-19 infection.