Scientists believe that the Omicron super-mutant strain of Covid that is causing panic across the globe may have originated in rodents.
Since South African scientists discovered the existence of this mutation last week, experts have puzzled over the origin of it.
Omicron contains 32 mutations of its spike proteins. This is nearly five times the number found in Delta. It’s also more infectious than Delta. Vaccines may be less effective because it has a divergent nature.
In recent times, it has been revealed that Omicron, which was not observed by scientists, has evolved in the darkness. Omicron split from Delta and Alpha in evolutionary terms sometime around the middle last year.
Omicron was possibly found in an immune-compromised patient with undiagnosed AIDS. This would have provided Omicron with time to adapt to his immune system and resulted in multiple mutations.
However, Professor Kristian Andersen at Scripps Research Institute, California has suggested that Omicron could have originated in rodents, who are known to carry the coronavirus. This is after an infected person passed it to them.
This is why the animal split with its evolutionary branch. It ‘vanished’ at some point in 2020.
Omicron would have been infected by an animal host’s ancestor, then it would have become highly mutated. The virus then spread rapidly to humans in reverse zoonosis.
Professor Andersen’s theory was based on the observation that Omicron differed from other Covid variants at the end of last year but genomic testing suggested it had only begun circulating among people in October.
Omicron is so unique because of what happened between the two periods.
What if Omicron evolved from rodents? A scientist says that a popular theory about the supermutant Covid variant developing in immunocompromised patients doesn’t hold up.
Omicron has nearly five times the number of spike proteins mutations as Delta. Delta’s mutations allowed it to beat Alpha and became the dominant strain. Omicron is also at risk.
Omicron is now spread across the globe, just a week after it was discovered in Southern Africa
A total of 42 cases of Omicron have now been detected in the UK, 22 in England and 10 in Scotland, while the vaccination status of the infected individuals is unknown none have required hospitalisation
Although stating that it is theoretical, Professor Andersen stated in a tweet that he favors a zoonic animal-based origin for Omicron because ‘the lineage in immunocompromised patients(s) is long and undetected circulation for that long seems unlikely’. Also, Covid was previously shown to move between species.
Second, Omicron’s mutations were also found in rodent species like mice and hamsters.
Covid is believed to have originated from a species of bats. The virus was then transmitted from one animal species to another. Covid has been discovered in mink in Denmark fur farms and deer in Canada.
Professor Andersen added that while many scientists have concluded Omicron came from an immunocompromised person, such as HIV patient, it was too early to call.
While that is certainly possible, there are no data to support it. He wrote, “Let’s not close our eyes to any hypotheses.”
When asked about theories, British experts replied that they preferred the immunocompromised patient theory.
Responding to this theory, Professor David Livermore from the University of East Anglia, who is a microbiologist, said that Omicron split with its ancestors sometime ago. However, he also suggested that Omicron’s mutation was probably the result of an immunocompromised patient theory.
He stated that Omicron has a very long history with its ancestors. It also exhibits an extraordinary combination of many changes.
“It’s more probable that it was selected under high selective pressure such as in chronically-infected patients with immunosuppression.
Professor Lawrence Young of Warwick Medical School, who is a virus expert, said that we are still in the early stages of understanding Omicron’s mutations.
He stated that while these people can model as many things as they want, using it to try and predict the biology of the virus’ behaviour is at best very speculative.
‘It’s very difficult to predict what this combination of mutations really means for infectiousness and immune evasion.’
Professor Young added that previous research points still suggests an immunosuppressed Covid patient having the virus for months as the likely origin of Omicron.
He stated that “Differential select pressure in immunocompromised hosts can serve as an incubator for the emergence variants associated with immune escape,”
There are many reports that prolonged infections can occur in immunocompromised people (70-100 days). This includes transplant recipients as well as patients with autoimmune disease. The variants may be more transmissible and less immune evasive.
‘These variants could then spread to other people – especially those who are unvaccinated.’
Today, 42 Omicron cases have been reported in the UK. The cases do not require hospitalization and are mild. Health authorities have not yet disclosed whether the Omicron status has been confirmed.
This mutant strain quickly becomes the predominant variant of Covid South Africa.
South Africa data shows that the R-rate rose to more than three percent in South Africa since Omicron was established in Gauteng.
As the Omicron epidemic has intensified, South African’s reproduction rates have jumped from below one percent to three percent in less than a month. The super-strain is outpacing Delta at a rapid pace.
Public Health officials in Guateng province estimated the R value — a key measure used to gauge how fast a wave is growing — could be as high as 3.5. The R rate in the UK has been below 1.6 for comparison.
Omicron virus has seen a dramatic rise in South Africa’s cases. Most of these cases are concentrated in Guateng. Guateng is the country that alerted the international community about this highly-evolved virus in November 24.
The national rate of cases rose by 37% to 11,535 last Thursday. This is a significant increase from the 8,500 reported yesterday. Within a matter of weeks, the strain has overtaken all other varieties in the country. It now accounts for 75% of the sequenced samples.
Yesterday’s preprint published in South Africa found that this strain has at least two-and a half times the ability to re-infect people as compared with all others.
This may explain why the disease is rapidly spreading in Guateng province where 80 per cent of residents have natural immunity. It has not spread in countries that it was detected, such as the UK which took weeks to detect it. Only 25% of South Africans have been vaccinated, as opposed to 70% in Europe, the US, and UK.
Omicron’s infectiousness is undisputed, but there are growing concerns about its ability to evade vaccinations and the severity of the disease it will cause. According to the World Health Organization (WHO), the latest variant has not caused any deaths anywhere in the world.
South African public health professionals and WHO insist that cases of the disease are not severe and that vaccines against it should be effective despite the lack of data.
But UK Health Security Agency (UKHSA) epidemiologist Meaghan Kall warned that data currently suggests Omicron may be ‘worse’ than Delta — although the picture is still emerging.
She stated that she is ‘highly skeptical’ about the possibility of milder symptoms. However, infections might only seem less severe if people are immune to other strains.
Doctors in Norway say that Omicron was contracted by 60 people at a Christmas party. They report mild symptoms like headaches, sore throats, and fatigue. All of those infected, however, are young. They are likely to have had their vaccines.
Although optimism is evident, South African hospitals are seeing an increase in admissions, with Thursday’s 274 being up 180% on last week. This despite the fact that they have been rising steadily from a low baseline.
Researchers are at an all-time high speed trying to determine if Omicron has a higher transmissibility and death rate than other mutant strains. They say that reliable estimates could take up to a week.
Early reports in South Africa suggest that many cases are either completely or mildly symptomatic. It is not clear if this could be because of the spread of the strain to older individuals.
According to the WHO, it’s a mild strain. Christian Lindmeier, a spokesperson for WHO, told journalists in Geneva today: “I haven’t seen any reports about Omicron-related deaths.”
“We are collecting all evidence, and will continue to find more evidence.
“The more people we test, the more places… We will find more cases, more data, and hopefully, not only deaths, but more.”
Dr Kall however said that the claim of a new strain being less dangerous is not true.
On Twitter, she wrote: ‘I am extremely skeptical that it could be more mild. It’s best to assume it is similar in severity as Delta… however, you will see milder symptoms than Delta because more people are immune now.
Pre-prints published yesterday indicated that Omicron had three times the chance of re-infecting people who’d had Covid previously.
South African scientists reported that there were 35,670 cases of reinfections in South Africa since the outbreak of the pandemic. The risk of reinfection increased by 0.7 percent during last summer’s Delta-fuelled second winter wave and Delta wave this summer.
However, the likelihood of getting the virus has increased to at most 2.4.
Researchers from Stellenbosch University near Cape Town said that Omicron is more able than others to overcome immunity.
The preprint means that the paper hasn’t been reviewed by any other scientists. These scientists then verify its conclusions.
Simon Clarke, a microbiologist from Reading University said that the data were the first indication Omicron might be immune to previous Covid infections.