What is the Delta plus variant and should we be concerned?
– Why are we seeing new variants?
All viruses mutate over time and Sars-CoV-2 – the virus which causes Covid-19 – is no exception.
Over time, changes can build up in the genetic code of the virus, and these new viral variants can be passed from person to person.
Most of the time the changes are so small that they have little impact on the virus but once in a while, a virus mutates in a way that gives it an advantage, for example making it spread more easily.
– Do we need to be concerned by each change in the virus?
No, viruses evolve. They have to to stay ‘alive’. Some variants are simply investigated and disappear on their own. Some don’t circulate very widely. But a few do become so-called variants of concern.
Remember the variant first found in Bristol? There was a furore when it was discovered that the Alpha variant, first identified in Kent, cropped up with a mutation called E484K.
Yet to date there have only been 46 lab-confirmed cases.
– When would we need to be concerned?
Variants can become concerning if they change the way the virus spreads, how severe the disease is and whether it affects the performance of vaccines, drugs and diagnostic tools.
The Delta variant is concerning in the UK because it is far more transmissible than the Alpha variant. But so far the data shows that the vaccines are holding up pretty well against it in keeping people out of hospital.
– So do we need to be concerned about Delta plus?
Not at the moment, experts say. There have been some suggestions that it might evade protection from vaccines because of the mutation it is carrying, but there has not been a great deal of cases, so it is really difficult to determine whether Delta plus could evade vaccines. We also don’t know whether it is more transmissible or if it will lead to more hospital admissions and deaths.
Delta plus is the B.1.617.2 variant of the virus which causes Covid-19, with the addition of K417N mutation in the spike protein of the virus. So far there have been 41 cases in the UK, according to Public Health England data. It is also referred to as AY.1.
“Delta+ represents 0.00002% of all delta variants sequenced to date. There is no evidence the strain is currently expanding in any country,” said Francois Balloux, professor of computational systems biology and director at UCL Genetics Institute.
It was first observed on April 5 in India and has been found in several countries where it has remained at low frequencies and around 160 cases have been identified globally, Prof Balloux added.
– Didn’t someone say something about Nepal?
In Nepal it has been estimated to account for around 4% of cases but this was based on a very small number of actual cases – just three, Prof Balloux said.
In the UK the red travel list was first published on May 7 and Nepal was added to it on May 12.
– What have the experts said?
Prof Balloux said at this stage “there is no particular cause for concern” about Delta plus. Meanwhile Brendan Wren, professor of vaccinology at the London School of Hygiene and Tropical Medicine, told Sky News that “scary variant stories” could make people “frightened to go outdoors”.
Last week, Susan Hopkins, strategic response director for Covid-19 at Public Health England, said that “we are living in a world of variants”
– How are we tracking variants?
Very early on in the pandemic, health officials ramped up sequencing capabilities so they could monitor changes in the virus’ genetic code.
Dr Hopkins told MPs on the Science and Technology Committee last week that at the moment 25 variants were “under monitoring” and eight “under investigation”.
“All of them have mutations that we’re concerned about, but mutations alone is not enough to predict whether it’s really going to impact on our journey through vaccines and impact on the public health risk of hospitalisation,” she added.
– What other variants of concern are being monitored in the UK?
Alpha, Beta and Gamma.
Alpha was first identified in Kent and was the first variant of concern to spread rapidly around the world. It was found to have a significant transmissibility advantage over the original virus.
At the time it was spreading there were very few vaccinated people so it has unfortunately been responsible for a significant number of deaths.
To date more than 272,000 cases of the variant, also known as B.1.1.7, have been identified in the UK. Before the Delta variant took hold, it was the dominant strain in Britain.
Beta was first identified in South Africa and appears to have emerged around the same time as the variant originating in the UK.
It has the E484K mutation which laboratory studies have shown may be capable of escaping the body’s antibodies, which makes it concerning. There have been just over a thousand cases in Britain.
Experts are also monitoring the Gamma variant, also known as P.1. which was first detected in Manaus, Brazil, and in travellers in Japan from Brazil.
It shares some important mutations with the variant first identified in South Africa. Just over 200 cases have been identified in the UK.