Why variants like XBB.1.5 matter

Omicron subvariants (including XBB.1.5 “Kraken”) are highly transmissible and can partially escape immunity. That reality elevates the importance of robust diagnostics that keep pace as the virus evolves. 

Why our design still works

Most mutations that define Omicron sublineages concentrate in the spike (S) protein, while many high-performing rapid antigen tests—including GBC’s—target the nucleocapsid (N) protein, a more conserved target used by leading test makers and in peer-reviewed evaluations. This design choice helps preserve detection across variant waves.   

Test smart: what regulators and clinicians recommend

Real-world accuracy improves when you follow serial testing:
• If you have symptoms and the first antigen test is negative → test again after 48 hours.
• If you have no symptoms but exposure/concern → three antigen tests 48 hours apart (or confirm once with a NAAT/PCR).
These are current FDA/CDC recommendations for at-home/POC antigen testing.  

How leaders communicate variant readiness (competitor snapshot)
• Publish variant checks: For example, Abbott publicly states BinaxNOW continues to detect Omicron subvariants including XBB.1.5, because it targets N-protein rather than spike. 
• Set user expectations: Major brands (BD Veritor, QuickVue) clearly explain serial testing windows and intended use for symptomatic/asymptomatic testing.   
• Share performance context: Independent studies show RAT performance can vary by product and subvariant, so transparent, ongoing evaluation is key.  

What this means for GBC customers
• Right target, resilient design: By targeting N-protein, our test is engineered to remain effective as spike-heavy variants emerge. (Note: N can mutate too; that’s why continuous surveillance matters.) 
• Follow the 48-hour rule: Negative today? Retest in 48 hours (and up to three times if asymptomatic) to reduce the chance of missing early infection.  
• Use PCR to confirm when needed: If symptoms persist or clinical decisions are critical, confirm with a NAAT/PCR. 

Bottom line

The viral landscape will keep shifting. Pair a conserved target (N-protein) with smart serial testing to protect accuracy in the Omicron/XBB era—and rely on manufacturers who publish variant updates and continue wet-lab/in-silico surveillance to back the claim.