A Guide to the COVID-19 Variants: What You Need to Know About Testing and More

Multiple SARS-CoV-2 variants have emerged since the start of the pandemic, and experts, including the CDC Director Dr. Rochelle Walensky, have spoken about the urgency to vaccinate as many people as possible before more contagious variants of the virus can spread widely.

The race against the variants is underway. Here’s what you need to know about them:

What is a variant?

Like all viruses, SARS-CoV-2 (the virus that causes COVID-19), is constantly mutating as it moves through the population, causing new variants to emerge. Variants contain changes (mutations) in the virus’ RNA.  Most of these variants are inconsequential from a clinical perspective, though they’re useful for tracking the spread of the virus through the global population.

How does the virus mutate?

Coronaviruses, like SARS-CoV-2, are known for crown-like spikes on their surfaces called spike protein, which is how the virus attaches to and infects host cells. Some mutations in the spike protein do have the potential to increase the ability of the virus to spread or cause more severe illness. Additionally, these mutations can allow the virus to evade protective antibodies induced by previous infection and/or vaccination and detection by testing methods. These are the variants that scientists are avidly tracking.

Which variants with clinical implications are widely circulating?

A U.S. government interagency group has established three classifications for the SARS-CoV-2 variants it is monitoring: Variant of Interest, Variant of Concern, and Variant of High Consequence. 

We have been regularly tracking variants of the virus throughout the pandemic. Here are the variants we are seeing in our PCR testing.

• Alpha (B.1.1.7, Q.1-Q.8)

• Beta (B.1.351, B.1.351.2, B.1.351.3)

• Delta (B.1.617.2)

• Epsilon (B.1.427, B.1.429)

• Eta (B.1.525)

• Gamma (P.1, P.1.1, P.1.2) 

• Iota (B.1.526)

• Kappa (B.1.617.1)

• Lambda (C.37)

• Mu (B.1.621)

• Omicron (B.1.1.529, BA.2, BA.4, BA4.6, BA.5, BQ.1, BQ.1.1, XBB.1.5)

• Zeta (P.2)

The CDC has established a national genomic surveillance program to identify new and emerging SARS-CoV-2 variants in the US.  For up-to-date information check out the COVID Data Tracker (https://covid.cdc.gov/covid-data-tracker/#variant-proportions).

How do variants like Omicron respond to diagnostic testing?

The great news is that to date no mutation has curbed the accuracy of Labcorp’s PCR tests that identify active COVID-19. That’s because our tests target the nucleocapsid protein of the virus, which is less prone to mutations as it must be faithfully copied from generation to generation for the virus to survive. Given that the Omicron variant is highly mutated in the spike protein, Labcorp’s PCR test will still be effective at diagnosing COVID-19 if someone is infected with Omicron.

Because our tests target the SARS-CoV-2 nucleocapsid, which is relatively well conserved across variants, our PCR tests can detect a SARS-CoV-2 infection due to the currently known variants. The sensitivity of our PCR test is not impacted by the variants. If you need to get tested, you can order a Pixel by Labcorp home collection kit here or talk to your doctor.

Labcorp continues to monitor the performance of all SARS-CoV-2 tests that we offer against newly emerging viral variants.

Is the U.S. testing for variants?

Continued genomic sequencing of the SARS-CoV-2 virus in new cases will provide a far more accurate picture of how variants are spreading and enable public health officials to respond effectively. Labcorp is proud to be working with the CDC on this effort. Because our labs receive thousands of samples from many states, we are uniquely positioned to catalog SARS-CoV-2 variants. These efforts provide the CDC information to inform national and state public health actions aimed at ending the pandemic.

The federal government is also taking steps to accelerate this important work; specifically, the recent stimulus bill directs $1.75 billion to the CDC to support genomic sequencing and surveillance initiatives. You can find estimates on the prevalence of the most common variants in the US here.