Understanding COVID Variants: Symptoms, Lists, and FAQs

medica-seed-editor · October 6, 2026, 7:08am

Learn about the different COVID variants, including the Omicron strain, to understand how they spread and affect your health.

What are COVID Variants?

Viruses constantly evolve, which leads to the creation of new strains or variants. Most of these changes do not alter how the virus functions, but some mutations can change how it behaves. Global researchers track these shifts to determine if certain versions spread more quickly, cause more severe illness, or resist vaccines and medical treatments.

Health experts use a classification system to track these changes:

Variant of Concern (VOC): Strains that spread faster, cause more severe disease, or significantly reduce the effectiveness of tests, treatments, and vaccines.
Variant of Interest (VOI): Strains that may spread more easily or show genetic markers that suggest they could be harder to treat or test.
Variant Under Monitoring (VUM): Strains being watched to see if they eventually become variants of interest.

How Do Mutations Occur?

Coronaviruses store their genetic information in RNA. When the virus enters a person’s cells to replicate, it makes copies of this RNA. If a mistake occurs during this copying process, a mutation happens. These random accidents are a natural part of how viruses multiply. While many mutations have no impact, some can make the virus more contagious, allowing that specific variant to become more common.

The Omicron Strain and Newer COVID Variants

First identified in Botswana in November 2021, the Omicron variant quickly became the most prevalent strain globally. It is known for spreading more easily than previous versions, likely due to mutations in the proteins that help it attach to human cells.

Several subvariants have emerged from this lineage:

BA.2 (Stealth): Initially thought to be less contagious, it later proved to be as transmissible as the original BA.1.
BA.4 and BA.5: These appeared in South Africa and are considered highly contagious, with BA.5 becoming dominant by mid-2022.
XBB: A combination of two BA.2 strains that can better evade immune defenses.
EG.5 (Eris): A descendant of XBB that became a primary version by August 2023.

Past COVID Variants

Before Omicron, other notable strains circulated:

Delta: Found in India in 2020, it was up to 50% more transmissible than earlier versions and dominated the U.S. in late 2021.
Alpha: First noted in England in late 2020; it was believed to spread more easily.
Gamma: Spotted in Brazil in early 2021, this strain may have been able to infect people who previously had the virus.
Beta and Mu: Other strains identified in regions like South Africa and Colombia.

COVID Variant Symptoms

While the general signs of infection remain consistent, some strains show subtle differences. Common indicators include fever, cough, fatigue, shortness of breath, body aches, and loss of taste or smell.

However, Omicron strains often produce more cold-like symptoms, such as a runny nose and sore throat. Conversely, with the Delta variant, loss of smell and coughing were reported less frequently.

When to See a Doctor

Seek medical attention if you experience:

Difficulty breathing or severe shortness of breath.
A high fever that does not resolve.
Symptoms that follow a pattern of fever, then cough, followed by muscle pain and nausea.

COVID Variant FAQs

What is the Omicron variant?

It is a highly transmissible mutation of the SARS-CoV-2 virus first reported in November 2021. It generally causes less severe illness than earlier strains, though serious cases still occur.

How do variants happen?

They form when the virus makes a copying error in its RNA while reproducing inside a host’s cells.

Does the vaccine protect against Omicron?

Yes, vaccines continue to provide strong protection against death and hospitalization. Bivalent vaccines are specifically designed to target both the original strain and Omicron.

How is a variant diagnosed?

A standard COVID-19 test can confirm an infection. Identifying the specific variant requires specialized, expensive testing that is not typically performed for every patient.

Disclaimer: This content is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.