The Delta Variant May Cause Different COVID-19 Symptoms

Woman checking for a fever and feeling cold symptoms.

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Key Takeaways

  • The Delta variant may be changing which COVID-19 symptoms are most common.
  • More people are reporting cold-like symptoms such as headaches and sore throats as opposed to a loss of taste and sense of smell.
  • The overall range of symptoms for COVID-19 hasn’t changed, so watch out for all the known symptoms, including the ones that might now be less common.

When COVID-19 first emerged over a year ago, health officials warned the public to watch out for some hallmark symptoms like fever, continuous coughing, and a loss of taste and smell. Now, as the highly transmissible Delta variant spreads globally, it seems new symptoms may be afoot.

During a briefing last month, Tim Spector, MD, professor of genetic epidemiology at King’s College London and co-founder of the ZOE COVID Symptom Study, announced that the Delta variant appears to have changed which COVID-19 symptoms commonly manifest.

The ZOE COVID Symptom Study is a mobile application in the U.K. where users can report infections and input symptoms to contribute to ongoing scientific research. In the U.K., the Delta variant accounts for the majority of all infections.

According to their data, the top COVID-19 symptoms as of late are:

  • Headaches
  • Sore throat
  • Runny nose
  • Fever

In contrast, symptoms like cough and loss of taste and smell weren't as common anymore.

Delta Variant Is Shifting Common COVID-19 Symptoms

There are currently four variants of concern in the United States: Alpha, Beta, Gamma, and Delta. They all have different rates of transmissibility and impact on vaccine effectiveness. So it's no surprise they may also lead to different symptoms.

“For the Delta variant, we are studying the symptoms and getting more information,” Magna Dias, MD, FAAP, Yale Medicine physician and chair of pediatrics at the Bridgeport Hospital, tells Verywell. “But the symptoms reported from countries like India and England overlap do seem to show a shift in which ones are more common.”

Other variants trigger more traditional COVID-19 symptoms that resemble the flu, such as the loss of smell, fever, shortness of breath, or persistent cough. However, the Delta variant appears to present more like the common cold, causing upper respiratory symptoms such as a sore throat or runny nose.

“Anytime a virus mutates, it can cause differences in the symptoms it causes,” Dias says. “A common example of this is influenza. We know that influenza type B is more likely to cause calf pain than influenza type A. Sometimes there are advantages to the virus to do this. A virus that is less deadly, for example, is easier to spread and replicate.”

Even though the Delta variant may be changing which signs of COVID-19 are more likely to appear, the overall range of symptoms for the disease hasn’t changed. You should remain cautious if you have any of the identified symptoms, even ones that might now be less common.

“The symptom list for testing from the Centers for Disease Control and Prevention (CDC) hasn't changed,” Dias says. “They include fever, cough, runny nose, headache, and body aches. The difference in testing and isolation depends on vaccination status. Fully vaccinated individuals should check with their physician to see if they need testing.”

What This Means For You

Although the Delta variant appears to be changing which COVID-19 symptoms are more likely to appear, you should continue to look out for all the known symptoms of infection. If you think you may have COVID-19, call a healthcare provider and isolate yourself from other people. Keep in mind that being fully vaccinated does not ensure 100% immunity to the virus, so even if you've been vaccinated you could still be exhibiting symptoms.

COVID-19 Vaccines Still Provide Robust Protection

According to Tedros Adhanom Ghebreyesus, PhD, director-general of the World Health Organization (WHO), the Delta variant is more transmissible than all the other previously identified variants. It also appears to evade the immune system more easily, which explains why it’s quickly becoming the world’s dominant strain.

“The good news is the high efficacy vaccines, including the mRNA vaccines, do continue to provide protection from serious COVID-19 disease, including with the Delta variant,” Chris Beyrer, MD, MPH, Desmond M. Tutu Professor in Public Health and Human Rights at the Johns Hopkins Bloomberg School of Public Health, tells Verywell.

However, getting only one shot of a two-dose vaccine series, such as the Pfizer-BioNTech or Moderna vaccines, isn't enough to protect against the Delta variant. It’s crucial not to miss the second dose to receive the maximum protection that COVID-19 vaccines have to offer.

That said, since wealthy countries like the U.S. scooped up most of the world's vaccines, many nations still lack vaccine availability and accessibility.

“So far, vaccine coverage is not high enough in most parts of the world to be impacting the spread of the Delta variant,” Beyrer says. “This is why it is spreading so quickly.”

Because of the highly contagious Delta variant, it’s all the more important for people to get vaccinated against COVID-19, he adds. Being fully vaccinated is the best protection available right now.

“For all people—vaccinated and unvaccinated—stay home if you are sick, cover your cough, wash hands, and use masks,” Dias says. “Our biggest risk right now is that the virus will continue to mutate to a version that the current vaccines can’t protect against. This will mean needing to get a booster for the new strain. If we can prevent that by vaccinating enough people, we will be able to return to normal again.”

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. SARS-CoV-2 Variant Classifications and Definitions.

  2. World Health Organization. COVID-19 Virtual Press conference transcript - 25 June 2021.

  3. Planas D, Veyer D, Baidaliuk A et al. Reduced sensitivity of SARS-CoV-2 variant Delta to antibody neutralization. Nature. 2021. doi:10.1038/s41586-021-03777-9

By Carla Delgado
Carla M. Delgado is a health and culture writer based in the Philippines.