Omicron, a version that can be harder to track, is rapidly growing in England.
Only a handful of cases have been reported in this country of BA.2, but in the past week, the number of individuals who tested positive for the subvariant more than quadrupled.
Data from the UK’s largest Covid surveillance lab shows BA.2 was behind 0.8 per cent of all positive samples in the seven days to January 15 — up from 0.2 per cent the week prior.
This suggests that approximately one-third of the 125 Covid positive people tested in this time period were exposed to the subvariant.
For comparison, the once-dominant Delta mutant strain made up only 0.5% of all cases last week.
Delta was almost entirely pushed out following the arrival of the ultra-virulent original Omicron variant in late November, which now accounts for the vast majority of domestic cases.
BA.2 is not like the Omicron. It can only be confirmed via lab analysis and not by aPCR. This has caused it to become more difficult to track, leading to its being nicknamed a ‘stealth’ variant.
Scientists suspect that BA.2 might have evolved to become slightly more transmissible then Omicron. This could lead to BA.2 becoming the UK’s most dominant Covidvirus.
Already, there are signs BA.2 is outstripping the Danish ancestral strain. It now accounts for 45 percent of all cases.
Even though the Scandinavian country has similar restrictions as the UK, and was hit roughly at the same time by Omicron, its daily cases nearly doubled within a week.
BA.2’s rise in England comes as infections start to creep back up after falling for two weeks straight, with 88,447 new cases yesterday.
However, Dr Tom Peacock of Imperial College London is a virologist and said that BA.2 will not be any more severe. It won’t have any’substantial effect’ on current UK situation, he insists.
Pictured above is the data from the Sanger Institute — one of the largest Covid surveillance centres in the UK — which shows BA.2 has now outpaced Omicron
The above shows the number of BA.2 lineages detected by the Sanger Institute — one of the UK’s largest Covid surveillance centres — over the week to January 8 (left) and January 15 (right) broken down by local authority
This graph compares daily Covid cases in Denmark to the UK. The graph clearly shows that Denmark has witnessed a greater spike in Covid cases than the UK, which accounts for 45% of all cases.
This graphic shows the number of Covid-related deaths per million. The rate is greater in the UK (red), but this is still a poor indicator due to how long it takes for someone to become seriously ill from the virus.
Denmark (red), and the UK have each vaccinated an equal number of citizens with a booster vaccine. Denmark was slightly behind the UK’s program.
The data shows that the UK and Denmark both have similar test rates per 1000 people.
Scientists say BA.2 is different from Omicron by about 20 mutations. However, only a small number of these might make BA.2 more effective at resisting the effects of vaccines.
But it still carries the changes that made Omicron more transmissible — and milder — than previous strains, but it is harder to detect.
The original strain has a specific alteration — known as an ‘S’ gene dropout — which meant it could be detected through PCR tests without the need for lab analysis.
This isn’t the case at BA.2.
But it doesn’t necessarily mean BA.2 can’t be detected using PCR. To confirm, additional analysis will be required.
Omicron-infected people have strong protection.
Scientists in Denmark have discovered that Omicron was not the only thing that a person who had Omicron before catching BA.
Data from the Sanger Institute shows there were 300 cases of BA.2 detected in England last week, out of 38,000 samples analysed. It was a significant increase from the 78 reported last week.
Infections in Delta dropped by 482 to just 179 during the same time period. Delta is also carriers the “S” gene dropout.
Brent (9 cases) and Barnet (9 cases) were the areas that had the highest number of BA.2 cases. Both are located in London.
Former head of Covid surveillance, Sanger’s Dr Jeffrey Barrett said that a positive test for ‘S in England’ is more likely than a negative test for Delta.
Both are less than BA.1 (the Omicron original variant).
Because of the severity of this outbreak, Britain currently checks around one out of ten variant cases. This means that the actual number of BA.2 infection per week could be close to 1,000.
The rising number of BA.2 cases coincides with the decrease in the UK’s spread, which has seen an increase week-on-week over the last two consecutive days.
However, schools were also reopened earlier this month, raising concerns from certain quarters about the possibility of an increased incidence of infections.
Denmark is recording 6500 new cases per year, while the UK records 1,300.
Its Staten Serum Institute — which monitors the country’s Covid variants — said it had also recorded a handful of cases where someone who caught Omicron was later infected with BA.2.
The population of both countries has been boosted by 60 percent against Covid and they are conducting similar tests.
Francois Balloux is a University College London geneticist who said that it wasn’t clear if Denmark’s spiralling infections were caused by BA.2 or had it just “surfed” the Omicron waves of infection.
MailOnline was informed by him that the high rate of infection in Denmark could be due to their low rates of hybrid immunity, which is a combination vaccines and previous infections.
Professor Balloux indicated that it would be a surprise if BA.2 triggers another wave in the UK.
Since the first detection of BA.2 in South Africa, approximately 2,093 BA.2 cases have been reported worldwide.
There have been 40 cases, which include the US, Australia, and UK. There have been 27 reported cases in the US so far.
Dr Peacock (Imperial College London) said via Twitter that he was very surprised by a second wave of BA.2 at this point.
This is a Delta to Omicron-level change that isn’t possible despite having slightly more transmissibility. Instead, this is expected to be slower and less subtle.
“That said, it would not surprise me if BA.2 replaces Omicron over the coming months by slightly better ‘optimised mutations.”
He stated that early observation from India and Denmark suggests there is not a dramatic difference between Omicron’s severity.
“These data should be solidified in the coming weeks.
“I agree with you that vaccine efficacy against Omicron and BA is unlikely to differ significantly.” It is very likely.
Last week, the UK Health Security Agency declared BA.2 to be a “variant under investigation”.
This group is for those variants which are spreading already in the UK and will likely be more easily transmitted and can evade vaccinations better than other.
One step lower than a “variant of concern”, which is a designation for mutant lines like Omicron and Delta, it’s still a significant level. The UKHSA may still decide to put it in the highest classification.