Testing and Variants

Many people are concerned about the new variants of COVID-19 emerging worldwide. Some patients are wondering what our current tests tell us about these new strains. Here are the two most common questions and their answers:

Will the test be positive if I have one of the SARS-CoV-2 variants?

• Yes. The PCR tests being used by SVMC and other labs detect all of the COVID-19 strains in circulation.
• The variants each have slight modifications, through genetic drift, to the ribonucleic acid (RNA) coding for outer protein(s).
• The PCR test detects multiple segments of the RNA, usually around three, not the outer protein itself.
• The RNA of the virus has not mutated to such a degree to evade detection by the PCR tests in use currently.
• New variants are being monitored by the CDC and testing companies in the event that the tests need modification when a new variant is recognized.

Will the test tell me if I have a variant and which one? 

• No. The PCR test used by SVMC and other labs does not differentiate between variants of the virus.
• The state of Vermont is sending a sample of positive specimens out for genomic sequencing to differentiate variants. These include a sample of specimens from SVMC.
• Testing of waste water in Burlington shows the presence of two COVID-19 virus mutations that are associated with the B.1.1.7 variant, which was first detected in the United Kingdom.

Have other questions? Ask at wellness@svhealthcare.org.

Trey Dobson, MD, is the chief medical officer and an Emergency Medicine physician at Southwestern Vermont Medical Center.