Delta Plus variant: new Covid strain more infectious but less likely to cause symptoms

The AY4.2 Covid strain is also known as Delta Plus

The Delta Plus AY4.2 Covid variant is less likely to cause symptoms of Covid-19, new research has suggested.

But what is the variant and what are the symptoms associated with it?

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What is Delta Plus?

AY4.2 - also being called Delta Plus by some - is a variant of Covid.

The original Delta strain was classified as a variant of concern in the UK in May 2021, after overtaking the Alpha variant to become the dominant type of Covid in circulation.

In July 2021, experts then identified AY.4.2, which is an offshoot or sublineage of Delta that has slowly been increasing since then.

The variant includes some new mutations affecting the spike protein, which the virus uses to penetrate our cells.

However, it has been found to be less likely to cause symptoms than the dominant form, according to new research.

Scientists on the React-1 study analysed more than 100,000 swabs taken across England with the majority taken between 19 October and 5 November 2021.

The results suggested that over that period of time, the infection rate for England was 1.57% - which is a figure that includes both symptomatic and asymptomatic infections – with prevalence highest among children aged 13-17, at over 5%.

The team added that while rates were lower in older adults, levels had doubled in those aged 65 and over compared with the previous round of the study carried out in September.

What are the symptoms?

Currently, there is nothing to suggest that the symptoms of infection with the Delta Plus variant are different to other coronavirus strains.

The main symptoms of Covid-19, according to the NHS, are:

  • a high temperature – this means you feel hot to touch on your chest or back (you do not need to measure your temperature)
  • a new, continuous cough – this means coughing a lot for more than an hour, or three or more coughing episodes in 24 hours (if you usually have a cough, it may be worse than usual)
  • a loss or change to your sense of smell or taste – this means you’ve noticed you cannot smell or taste anything, or things smell or taste different to normal

Does the vaccine work against it?

It has previously been suggested that AY.4.2 may be around 10-15% more transmissible than the original Delta variant, but others said the new finding requires further scrutiny.

Dr Simon Clarke, associate professor in cellular microbiology at the University of Reading, said: “What the data doesn’t tell you is who those infections [of AY.4.2] are in. So if they’re in younger people, or if they’re in a community that has a higher than average vaccine uptake, then that might account for things.”

There is no evidence to suggest the vaccine is not effective against the strain and there is also no suggestion that a new update of the vaccine will be needed to protect against any of the existing variants of the pandemic virus.

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