In silico analysis of 3,900 influenza sequences shows comparable sensitivity for the test against the subclade K variant currently circulating.
Co-Diagnostics Inc has completed an in silico analysis confirming that its Logix Smart ABC test maintains reactivity against the influenza A H3N2 subclade K mutation currently circulating this flu season.
The analysis examined Co-Primers used in the CE-marked test, which simultaneously detects and differentiates influenza A, influenza B, and SARS-CoV-2. Results showed high homology against 3,900 influenza sequences, confirming comparable reactivity of the primer sets against the H3N2 subclade K variant.
The subclade K strain, also designated as J.2.4.1, represents a significant concern for the 2025 flu season as this year’s vaccine is mismatched with the variant, limiting natural immunity within communities. Countries including Japan and the United Kingdom have already experienced earlier than usual flu seasons following Australia’s record flu season in 2024.
“We have received customer inquiries regarding the performance of the Logix Smart ABC test against this year’s influenza strains,” says Dwight Egan, chief executive officer of Co-Diagnostics, in a release. “Based on the results of this analysis, we are confident that the test retains comparable sensitivity as when it was first developed on our proprietary platform more than five years ago.”
Target Region Unaffected by Mutations
The test’s Co-Primers target a region on the MP gene of influenza A, while the mutations associated with subclade K occur in the HA region of the genome. The analysis concluded that emerging H3N2 strains would not affect the test kit’s sensitivity.
According to the World Health Organization, seasonal influenza causes approximately 3 million to 5 million cases of severe illness annually, resulting in 290,000 to 650,000 respiratory fatalities. Influenza A subtype H3N2 has historically been associated with higher rates of hospitalization and death.
The Logix Smart ABC test received CE-marking in November 2020 and is intended for use by qualified and trained clinical laboratory personnel. The test is not approved or cleared by the US Food and Drug Administration and is for export only.
Point-of-Care Test in Development
Co-Diagnostics announced in November 2025 that it had initiated clinical performance testing for its Co-Dx PCR Flu A/B, COVID-19, RSV point-of-care upper-respiratory multiplex test. The company intends to submit the test to the FDA for 510(k) clearance.
Similar to the Logix Smart test, the flu A targets in the point-of-care test are not expected to be affected by H3N2 subclade K mutations.
The Co-Dx PCR platform, including associated tests and software, remains subject to regulatory review and is not currently available for sale.
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