Covid-19 variant tests emerge – but only for research


By sheer luck, Thermo Fisher Scientific and Applied DNA Sciences have found themselves with Covid-19 tests capable of differentiating the UK variant of the coronavirus. Now diagnostics groups are deliberately developing tests that can do this and more. Today Roche began selling the cobas Sars-Cov-2 Variant Set 1 test, capable of pinpointing infections with the UK, South Africa and Brazil strains. The molecular test detects mutations in the gene for the virus’s spike protein, and runs on Roche’s widely used cobas 6800 and 8800 high-throughput machines. The South Korean group Seegene got there first, however. In early March it said it had developed the world’s first variant diagnostic test, the Allplex Sars-Cov-2 Master assay, which can identify the same three strains, and detects two additional mutations. Neither test is authorised by the US FDA, and thus neither can be used by US healthcare professionals to diagnose patients. Roche’s assay remains research use only for now; under that designation scientists can use it to track mutation prevalence and assess potential impact on diagnostics, vaccines and therapeutics. The Swiss group declined to tell Evaluate Vantage whether it would seek emergency use authorisation for its test.

Detecting the variants: Roche and Seegene
Spike gene mutation Variant in which mutation found Effect of mutation Detected by Roche test?  Detected by Seegene test? 
B117 (UK) Might help virus evade some antibodies; associated with increased transmissibility Y Y
N501Y B117 (UK), B1351 (South Africa), P1 (Brazil) Helps virus latch on more tightly to human cells; associated with increased transmissibility Y Y
E484K P1 (Brazil) Might help virus evade some antibodies; possibly diminishes vaccine efficacy Y Y
P681H B117 (UK) Might help infected cells create new spike proteins more efficiently N Y
K417T P1 (Brazil) Might help virus latch on more tightly to human cells N Y
Source: company releases & published research.

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