The Animal Health Diagnostic Center Virology Laboratory will be updating the SARS-CoV-2 virus neutralization test (SARSCOV2SN). Over the last few years we have been testing samples using the ancestral Tiger 1 virus isolate, which was isolated in 2020 from an Amur Tiger and represent the D614G SARS-CoV-2 lineage. Since then, SARS-CoV-2 has continuously evolved and several variant strains (variants of concern [VOCs], e.g. alpha, beta, gamma delta and more recently Omicron and its lineages) have emerged in humans and in animals.

As a result of the evolution of the virus, more specifically of the Omicron VOC and its lineages, a shift in the neutralization profile was observed in our assay. This shift was characterized by decreased neutralization titers against the Omicron strain detected in serum from animals experimentally infected with ancestral viral strains. These results suggest that omicron may represent a different serotype of SARS-CoV-2 with limited cross-neutralization against the other VOCs and the ancestral virus.

Because of these new evidence, the Virology Laboratory will be testing all samples submitted for the SARSCOV2SN against two SARS-CoV-2 strains (Tiger 1, D614G; and Omicron BA.1.1). Titer results for samples submitted for vaccine titer checks or for detection of antibodies after suspected exposure to SARS-CoV-2 will be reported separately for each SARS-CoV-2 strain.  Since we will be testing against two viral strains, the cost of our SARS-CoV-2 SN will also increase from $53.00 to $63.00.

More information can be found in AHDC's test and fee catalog, search for: SARS-CoV-2 or SARSSN.