What is the delta variant?

COVID-19 Delta variant

The Delta variant of COVID-19 ("covid" for short) originated from India and spread rapidly worldwide in the middle of 2021. It is one of several variants, along with Omicron and Lambda, that emerged from the 2019 novel coronavirus.

According to the CDC, the delta strain features many of the same symptoms as the original version of covid. These symptoms include:

  • Fever or chills
  • Shortness of breath
  • Body ache
  • Dry coughing
  • Sore throat
  • Headache
  • Fatigue
  • Vomiting
  • Loss of taste and smell

Although the symptoms are similar, health officials classify delta as a more contagious variant than the original covid version. It also affects unvaccinated people more than vaccinated people.

When did delta emerge?

Health officials discovered the Delta variant in India in December 2020. Delta spread rapidly in India, then worldwide in 2021, becoming the predominant covid iteration in 2021.

While people primarily used delta in health contexts, you may also see or hear it used in other realms. For example, you might see it in a news story about how it's affecting the stock market. Or, you might see it in memes or TikTok videos poking fun at how it's affected our culture.


Once my mom heard about delta, she put us in lockdown for the next 2 months

South Park poking fun at the Delta name

Related Slang


Updated December 13, 2021

Delta definition by

This page explains what the slang term "Delta" means. The definition, example, and related terms listed above have been written and compiled by the team.

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