China has been experiencing a surge in Omicron BA.2 infection of late. Although it has been relatively successful prior to the latest wave in curbing the spread of the sars-cov-2 virus.
As at March 27, 2022, the novel coronavirus SARS-CoV-2 had infected about 1.27 million people and killed 11,890 in a country of 1.4 billion people ( 2 ). This is a good outcome compared to the US and other European countries with US recording almost a million death for a population of 334 million.
The "stealth Omicron" or Omicron BA.2 variant has challenged the Chinese authorities capability to keep the virus at bay since the onset of the pandemic. Research suggests that these sub-variants of omicron spreads faster than any known previous Sars-cov-2 variants.
As of 24th March 2022, China has had about 85.9% of its population vaccinated ( 1 ) with it's home grown vaccines (Sinopharm and Sinovac) made using attenuated Sars-cov-2 virus which have had the advantage of not creating local variants of concern unlike the mRNA vaccines. No variant of concern have originated from China except for the initial Wuhan virus.
The Omicron BA.2 variant has been nicknamed "stealth omicron" because of the genetic mutations that makes it indistinguishable from the Delta variant yet shares 30 similar mutations with Omicron as well as it's own unique mutations. It seems to be a partial hybrid between Delta and the original Omicron BA.1 with additional unique mutations.
It has been demonstrated that BA.2 is resistant to the BA.1 vaccine-induced humoral immunity. BA.2 is virologically different from BA.1.
BA.2 is between 30 percent and 50 percent more contagious than BA.1 and some researchers have raised a proposal that BA.2 should be given a letter of the Greek alphabet and be distinguished from BA.1.( 3 )
Infarct it appears BA.2 has undergone antigenic shift and the inherent characteristic will be concealed if the omicron nomenclature is retained which will be non-reflective of it’s true identity.
BA.2 appears to be more pathogenic than BA.1 but less pathogenic than delta.
It is evident that the spread of BA.2 may precipitate serious issue for global health if the wrong mitigation strategies are applied.
As this latest variant of SARS-CoV-2 sweeps the planet, question that will agitate the minds of pandemic-weary people will be: is humanity doomed to confront a succession of new variants for the foreseeable future, each one more contagious than the last? But what is happening is not different from what has been going on with the Influenza virus which we have been living with, the only difference is that the pandemic has brought the situation more vivid to our fore, hence it's not really a problem as the main stream media has tried to portray.
It's an inherent characteristic of RNA viruses such as SARS-CoV-2 and Influenza to mutate rapidly and they will keep mutating. However the majority of the mutations tends to be deleterious which makes the virus weaker and less virulent but can be more transmissible. Eventually some of these viruses will extinguishes itself through step-wise successive deleterious mutations.
Fortunately, evidence so far indicates that the disease symptoms caused by BA.2 are not more severe than those caused by BA.1 in vaccinated people or people who were previously infected with SARS-CoV-2.( 4 )
The World Health Organization (WHO) has also noted that even though the BA.2 is more transmissible than BA.1, there is no difference in severity. However there seems to be more report of gastrointestinal symptoms with Omicron BA.2 and hardly any pulmonary symptoms. ( 5 )
In a recent study (3), a Japanese team led by researchers from the University of Tokyo found that similar to BA.1, BA.2 sub-variant of Omicron appears to largely escape the immunity induced by COVID-19 vaccines. "Neutralization experiments show that the vaccine-induced humoral immunity fails to function against BA.2 like BA.1," the authors of the study said.
China's zero Covid policy have largely conferred vaccine induced protection given intravenously on the majority of the population which produces mainly systemic IgG antibodies that does not pose a threat to the omicron antigens hence this will be largely ineffective in controlling Omicron as seen in the latest surge that are affecting vaccinees.
Omicron symptoms are very mild hence it might be best to allow the virus to spread to the population and confer herd immunity.
Omicron attacks the external epithelial cells of the nasal and olfactory cavity and does not penetrate to the vascular regions. Hence systemic vaccine induced immune effectors are not within reach of the virus antigens which makes the vaccines inconsequential.
This implies Omicron will infect those that were protected from Delta and prior ancestral strains through vaccination that does not produce IgA antibodies at the point of entry of the virus.
However natural infection does produce mucosal IgA antibodies and hence cohorts infected naturally will still be protected for a reasonable period.
China may have to change it's Covid-19 strategy crafted pre-omicron, since the trajectory and behavior of the virus has changed as well as the pathogenesis.
The vaccines were formerly largely effective against the vascular effect of the virus, however omicron does not penetrate into the vascular region hence the vaccine is non effective against Omicron thereby causing the current surge of infection.
This evidence also calls for a change of strategy in the design and route of administration of vaccines for respiratory viruses that do not affect the vascular system and takes advantage of mucosal immunity.
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1. https://www.statista.com/statistics/1279024/china-coronavirus-covid-19-vaccination-rate/
2. https://www.statista.com/statistics/1092918/china-wuhan-coronavirus-2019ncov-confirmed-and-deceased-number/
3. https://www.biorxiv.org/content/10.1101/2022.02.14.480335v1.full
4. https://www.scientificamerican.com/article/what-we-know-about-omicrons-ba-2-variant-so-far1/
5. https://www.who.int/news/item/22-02-2022-statement-on-omicron-sublineage-ba.2
Lessons from China's "stealth Omicron" surge.
Hiya,
There is no 'virus' entity that exists outside of a computer and therefore there cannot be any variants!
Jo https://georgiedonny.substack.com/p/x-ray-crystallography-and-3d-computer