Delta variant symptoms: what you need to know

An image of Lucy Hoppe
Head of Clinical Evidence at Bupa
18 August 2021
Next review due August 2024

You may think you know the symptoms of COVID-19, but did you know there are more than 20 reported symptoms? And did you know the Delta variant of the virus has some symptoms that are different to other strains?

In this article, I’ll explain what the Delta variant symptoms are and how they are different to the classic symptoms. I’ll also talk about how Delta may affect you if you’ve been vaccinated, and what to do if you feel unwell.

What is the Delta variant?

Over time, viruses change and develop into new versions. These are called variants.

The Delta variant is one of four ‘variants of concern’ of COVID-19. A variant of concern means that it may be:

  • more transmissible (easily passed on)
  • more severe
  • less affected by vaccines

The Delta variant is now the most dominant strain of COVID-19 in the UK. Experts estimate that it is 40 to 60 per cent more transmissible than the previous dominant variant, the Alpha variant.

What are the main symptoms of COVID-19?

The main symptoms of earlier variants of COVID-19 are:

  • a high temperature
  • a persistent cough
  • a loss or change to your sense of smell or taste

Are Delta symptoms different?

The Delta variant produces different symptoms, according to the ZOE study. The ZOE Symptom Study has been collecting information through an app, where people have been logging their symptoms since March 2020. Over four million people from around the world have been taking part – it’s the biggest ongoing study about coronavirus. Information reported to the app shows that people are having different symptoms, either instead of, or in addition to, the main symptoms above. The new symptoms include:

  • headache
  • sneezing
  • runny nose
  • sore throat

What about Delta variant symptoms and vaccinated adults?

So far, the evidence shows that Delta symptoms may be different and vary in severity depending on whether you’ve had the vaccine or not.

According to the data from the ZOE app, the top five symptoms if you’ve had two vaccinations are:

  • headache
  • runny nose
  • sneezing
  • sore throat
  • loss of smell

If you’ve had one vaccine, they are:

  • headache
  • runny nose
  • sore throat
  • sneezing
  • persistent cough

If you’ve not had the vaccine, the top five symptoms are:

  • headache
  • sore throat
  • runny nose
  • fever
  • persistent cough

While these symptoms may not seem as serious as shortness of breath, for example, it does mean that you might not realise you have the Delta variant. And you could be spreading it to other people.

Many people who found out they had the Delta variant thought they had a cold or hay fever. That’s why it’s so important to be aware of these symptoms. The UK Government currently only advises you to self-isolate and book a test if you have one of the three main symptoms of COVID-19 listed near the top of this article. But you can order rapid lateral flow tests to do at home even if you do not have those main symptoms. Participants in the ZOE study who download the app can also order tests through the study if they have Delta variant symptoms.

Are Delta symptoms more severe?

It’s not clear if symptoms of the Delta variant are more severe. This is because the people most at risk of coronavirus have now had the vaccine (the elderly and those with underlying health conditions). Most new infections are in younger people, who are often healthier.

Some research has found that you may be more likely to need hospital treatment if you get the Delta variant. But some experts suggest there’s evidence that people who do go to hospital don’t need as much oxygen treatment or intensive care. Findings also suggest that there is a higher risk of reinfection (catching it again). More research needs to be done to understand the severity of the Delta variant.

Does a vaccine protect you from the Delta variant?

Data shows that vaccines are protective against the Delta variant. Vaccines are helping to stop people from having serious illness. However, you can still catch the Delta variant if you’ve had the vaccine, because the strain has changed. This is especially so if you’ve only had one vaccine. It’s also not known if you’ll develop long-COVID after getting the Delta variant.

Vaccinations, washing your hands and getting tested are all important ways to protect ourselves and others.

An image of Lucy Hoppe
Lucy Hoppe (she/her)
Head of Clinical Evidence at Bupa

    • The 21 symptoms of covid-19 to watch out for. ZOE COVID Study., published 18 March 2021
    • What are the new top 5 COVID symptoms? ZOE COVID Study., published 23 June 2021
    • Tracking SARS CoV2 variants. World Health Organization., last updated 4 August 2021
    • The Delta variant: why is it so dominant? ZOE COVID Study., published 13 July 2021
    • SARS-CoV-2 variants of concern as of 5 August 2021. European Centre for Disease Prevention and Control., published 5 August 2021
    • Main symptoms of coronavirus. NHS., page last reviewed 5 August 2021
    • About the ZOE COVID Study. ZOE COVID Study., accessed 10 August 2021
    • Delta variant impact on hospitalisation revealed. University of Edinburgh., published 18 June 2021
    • Sheikh A, McMenamin J, Taylor B, et al. SARS-CoV-2 Delta VOC in Scotland: demographics, risk of hospitalisation, and vaccine effectiveness. The Lancet 2021; 397(10293): 2461-2. doi:10.1016/S0140-6736(21)01358-1
    • Risk assessment for SARS-CoV-2 variant: Delta. Public Health England., published 23 July 2021

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