But it has a long way to go to take over from Delta, which dominates the world. And the long list of variants that first stunned the world before they fell off the map may be a reminder that viruses are unpredictable.
Take a look at the designated coronavirus variants here.
WHO has designated coronavirus variants either as variants of concern – meaning they appear dangerous enough to tolerate closer scrutiny and constant updates – or as variants of interest, or under surveillance as variants. Currently only five variants of the concern meet the definition: alpha, beta, gamma, delta and omicron.
According to WHO, the first sample of the Omicron or B.18.104.22.1689 lineage was taken on 9 November. This was seen due to the increase of cases in South Africa.
“This new version, b.1.1.529, appears to be spreading very quickly!” Tulio de Oliveira, Director of the Center for Epidemic Response and Innovation, South Africa, and a genetics researcher at Stellenbosch University said on Twitter.
In addition, genetic sequencing showed that it carried a large number of disturbing mutations on the spike protein – the knob-like structure on the surface of the virus that it uses to hold onto infected cells.
Some of those mutations had already been identified with other variants and were known to make them more dangerous, including one called E484K that can make the virus less recognizable to certain antibodies – the immune system proteins that control infection. Monoclonal antibodies are a front-line defense against and form the basis of treatment.
Like Delta, Omicron also has a mutation called D614G, which helps the virus better attach to infected cells.
Dr. Peter English, former president of the British Medical Association’s Public Health Medicine, said: “The number of mutations does not necessarily mean that the new variant will cause any problems, although it may make it more likely to appear different from the immune system. ” The committee said in a statement.
What worries scientists is the number of mutations affecting the spike protein. This is because most major vaccines target the spike protein. Vaccines made by Pfizer/BioNtech, Moderna, Johnson & Johnson, AstraZeneca and other companies all use small fragments or genetic sequences of the virus and not the whole virus, and they all use bits of the spike protein to elicit immunity. do for So a change in the spike protein that made it less recognizable to immune system proteins and cells stimulated by the vaccine would be a problem.
So far, there is no evidence that this has happened but there is no way to know just by looking at the mutation. Researchers will have to wait and see if Omicron causes more breakthrough infections than other types.
The second fear is that the mutations could help make the virus less sensitive to monoclonal antibody treatment. However, the WHO says it is unlikely that these mutations will affect other COVID-19 treatments, including the antiviral drugs in development and the steroid dexamethasone.
It takes an additional layer of testing above and beyond standard tests to detect infection to tell which type of coronavirus has infected someone. Genetic sequencing must be performed and takes longer than rapid antigen testing or PCR testing.
It is too early to tell whether Omicron causes more severe disease, although a doctor who treated some patients in South Africa told Reuters that his patients had only mild symptoms. “The most prominent clinical complaint is severe fatigue for a day or two, followed by headache and body aches and pains,” said Dr. Angelique Coetzee, a private physician and president of the South African Medical Association.
Those factors may have influenced the rise of the variant in South Africa, in contrast to countries where more people are vaccinated and fewer have immunosuppressive conditions.
Physical barriers will also work against any mutant virus. These include masks, handwashing, physical distancing and good ventilation. “Very uncertain but we know what works vs COVID-19: – Improve indoor ventilation – Quality masks/respirators – Avoid indoor crowds – Distance – Test, isolate, quarantine – Vax + Booster Now for Delta, ” Doctor. Jeffrey Duchin, Seattle & King County Health Officer, tweeted on Sunday.
While experts say they are watching closely, many have said they are not particularly concerned about Omicron just yet.
“I don’t think we should panic,” Robert Gary, a professor of microbiology and immunology at Tulane University School of Medicine, told Granthshala.
“The sky is not falling,” Dr. Peter Hotez, dean of the School of Tropical Medicine at Baylor, told Granthshala. “We haven’t seen any evidence that Omicron causes more severe disease than any other type.”
The delta version of the coronavirus is now the dominant lineage in the US and much of the world. According to the US Centers for Disease Control and Prevention, the delta variant accounts for 99.9% of cases in the US.
Also known as B.1.617.2, it is clearly more transmissible than other types, but it is still unclear whether it causes more severe disease.
It quickly replaced the B.1.1.7, or alpha, variant in most countries.
The delta spike also carries a set of mutations on the protein. It can also evade the immune system, which could mean that people who have once been infected with an older version may be more likely to catch it again. It also overcomes the effects of a monoclonal antibody treatment called bamlanivimab made by Eli Lilly and Company, but is sensitive to the protection offered by other monoclonal antibody therapies.
First identified as a variant of the concern last December, b.1.1.7 or the alpha version of the coronavirus was worrying public health officials last spring. It quickly spread throughout England and then throughout the world, quickly becoming the dominant lineage in the United States. It has now been demoted to “Variants Being Monitored” by the CDC because it has less influence in the US.
It was shown to be at least 50% more transmissible than the older lineage. It has 23 mutations, including a mutation called N501Y that enhances transmission.
It is completely susceptible to monoclonal antibody treatments and vaccines.
First seen in South Africa, the B.1.351 or beta variant has both the E484K mutation that is associated with immune evasion and the N501Y mutation suspected to help make several other variants more infectious. It has been shown to be 50% more permeable than older strains and survive dual monoclonal antibody treatment of Lilly, but not others.
Both blood tests and real-life use suggest that it can infect people who have recovered from the coronavirus and also those who have been vaccinated for COVID-19.
Vaccine makers trying to overtake the new variant by developing booster shots focused on B.1.351, as the variant could evade vaccine protection scientists’ most feared. But partial migration does not mean complete migration, and vaccines are still expected to protect people to some degree.
It was overtaken by Delta in South Africa and, despite the concern it caused, never gained much of a foothold in the US, and is now designated a Variant Being Monitoring by the CDC.
The P.1 or Gamma variant, which influenced Brazil, also never gained much space and is now a CDC version Being Monitoring.
Gamma carries both the E484K and N501Y mutations, along with more than 30 others. It has been demonstrated to evade the effects of Lilly’s monoclonal antibody treatment, but is not made by Regeneron. Blood tests show that it may partially evade both natural and vaccine-acquired immune responses.
Types of interest of WHO
lambda: Lambda or C.37 was designated WHO’s version of interest in June. The CDC does not mention it.
mu: Mu or B.1.621 sparked a flurry of fears when it was declared a WHO variant of interest in August, but it soon subsided. This is now designated Variant Being Monitoring by the CDC.
Variants being monitored by CDC
Epsilon: The B.1.427 and B.1.429 variants are commonly grouped together and known as epsilon. First seen in California, it has the same L452R mutation carried by Delta, but does not have some of the other mutations and is not overcome in the way that Delta did.
Iota: First seen in New York last November, the B.1.526 or Iota variant first spread, accounting for 9% of samples last April, but has now almost disappeared. It contains what is called a 484 mutation that helps the virus attach to infected cells more easily and makes the virus less recognizable to the immune system.
And: First seen in the UK and Nigeria, Eta, also known as B.1.525, carries the E484K mutation. This too has almost disappeared.
Zeta: Circulating in Brazil since last year, this variant, also known as P.2, also carries the E484K mutation and has not been found widely globally. According to the CDC, it has almost disappeared in the US.
There are no types named Nu or Xi. The WHO decided that “nu” sounded like the English word “new” and that Xi is a common last name.
Credit : www.cnn.com