Covid-19 Delta variant: what are the symptoms and why are they different?

The Delta variant is increasingly more prevalent in new infections in the US and around the world. Data collected from an app, tracking symptoms experienced by those infected by covid-19, shows that the variant considered of “concern” is "acting differently."

There are a number of symptoms associated with covid-19 but health officials have focused on just a few. The traditional symptoms of covid-19 people have been advised to look out for are a cough, fever and loss of smell or taste. Professor Tim Spector, who runs the Zoe COVID Symptom study which collects data from thousands signed up to the app, says these are now less common.

Delta variant "more like a bad cold"

Professor Specter posted a video on YouTube about the study's latest findings that the Delta variant is flying under the radar due to the changes in symptoms experienced. “Since the start of May, we have been looking at the top symptoms in the app users and they are not the same as they were,” Specter said. The change in symptoms people are reporting comes with the rise of the Delta variant as the dominant strain in the United Kingdom.

Younger people experiencing much more of what one would with a bad cold or have a general “funny off feeling.” Specter said that the number one symptom is headache, then followed by sore throat, runny nose and fever. The “classic” symptoms were now rarer such as a cough and “loss of smell doesn’t even come into the top ten anymore.”

This change in symptoms and the strains higher transmissibility are driving the infection rate in the UK. Young people think that they have a seasonal cold and go out with friends.

Delta variant could cause more severe illness

The Centers for Disease Control and Prevention (CDC) has now classified the Delta variant as a “variant of concern” a term used when a virus becomes more “sticky” able to infect more people, can cause more severe illness or can evade antibody defense more effectively. In a statement to NBC upon the strain reclassification the CDC said “based on mounting evidence that the delta variant spreads more easily and causes more severe cases when compared to other variants, including B.1.1.7 (Alpha).”

Professor Specter noted that the UK was seeing a rise in hospitalizations among the young and unvaccinated with the rise of Delta variant infections. Although there appears to be some reduction in the effectiveness of those vaccinated against covid-19, he said it was very minor in those that were “double vaccinated,” when a person has received both doses of either Moderna or Pfizer-BioNTech covid-19 vaccines. Those that had been “double vaccinated” and caught the Delta variant had “milder and shorter in duration version,” of the disease Specter said and they were less likely to go to hospital.

Delta variant becoming dominant strain

The Alpha variant which first appeared in England has been replaced by the Delta variant as the dominant strain in the UK accounting for over 90 percent of new infections. The rapid spread of the Delta variant has forced the UK government to push back its plans to reopen the economy by a month.

The “variant of concern” is making inroads in the United States going from just over one percent at the end of May to 10 percent of new infections. CDC Director Dr. Rochelle Walensky said she expects the Delta variant to become the dominant variant in the United States replacing the Alpha.