China creates flu vaccine using "revolutionary" approach | Xinhua

Martian

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Chinese scientists create flu vaccine from live virus using "revolutionary" approach | Xinhua

"In a proof-of-principle study, the vaccine they developed against flu proved effective in mice, guinea pigs and ferrets, the researchers reported in the U.S. journal Science.

'We believe our approach will become a general, simple and convenient approach for generation of live virus vaccines adapted to almost any viruses,' Professor Deming Zhou of Peking University, who led the study, told Xinhua.

'This will help control pandemics of influenza and other life-threatening RNA viruses.'

A major challenge for converting infectious viruses, such as those responsible for influenza, Ebola, Zika and AIDS pandemics, into live vaccines is to render them as avirulent as possible while maintaining their high infectivity to elicit sufficient immunity, Zhou said, noting achieving such a feat would 'represent a revolution in vaccinology.'"



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Generation of influenza A viruses as live but replication-incompetent virus vaccines | Science

 
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Martian

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China's Terminator Gene or Premature Termination Codon (PTC)

In the novel Chinese scientific advancement, the Chinese scientists spliced in a three-base codon to order the viral molecular machinery to terminate production of DNA (ie. stop duplication) or to stop making a particular protein. This is effectively a Terminator gene. The virus is still alive, but it can't reproduce.

A typical flu virus has 13,600 base pairs.

Scientists can splice in more Terminator genes, which are the premature termination codon (PTC). Practically speaking, three or four Terminator genes would stop a virus in its tracks. It is virtually impossible for a virus to mutate and fix the PTCs to allow it to replicate again.

Assuming 6.5 billion viral particles, the total number of mutations in those viral particles is 6x10E8.
With three PTCs, the probability of a simultaneous viral mutation to negate the three PTCs is 2x10E-7.
With four PTCs, the probability of a simultaneous viral mutation to negate the four PTCs is 1.38x10E-12.

If there is only one virus particle, the chance to develop resistance to three PTCs via mutation is 3.29x10E-16.
If there is only one virus particle, the chance to develop resistance to four PTCs via mutation is 2.27x10E-21.

In conclusion, if three or four PTCs are spliced into a virus then it can't reproduce.
 

Martian

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To clarify, the idea of splicing is not new.

However, it is a brand new concept to splice a "STOP" gene into a live virus and for it to effectively halt a viral infection in "mice, guinea pigs and ferrets."

IF the technique works in living human beings, a powerful solution to stop a viral infection has been DISCOVERED.

Currently, there is no medical solution to Ebola, Zika, or an AIDS infection. The Chinese discovery offers a potential solution if it works in humans as well as "mice, guinea pigs and ferrets."
 

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Genetically-modified Chinese Vaccine-Virus will only accept Artificial Amino Acid

The novel Chinese scientific advancement is far more complicated than merely splicing a STOP gene into a live virus. It also involved the genetic modification of the vaccine-virus to create a dependency on a man-made amino acid to survive. This artificial amino acid is a safeguard. It doesn't matter if the vaccine virus mutates, it still needs a human-made amino acid to function.

Thus, if multiple STOP genes are spliced into a live virus and a dependency is created for a multitude of artificial amino acids (through genetic engineering) then the Chinese Vaccine-Virus is quite safe. As I had shown with the earlier probability calculations, the probability of evolving away all of the STOP genes and Artificial-Amino-Acid dependency genes is infinitesimal.
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Will China’s scientists’ breakthrough sound death knell for world’s deadly viruses? | South China Morning Post

"The live virus used in the vaccine used by the researchers had its genetic code tweaked to disable the viral strains’ self-replication mechanism. But it was kept fully infectious to allow the host animal cells to generate immunity.
...

Analysis showed that the man-made virus had recombined with the wild virus so that the combined virus was unable to reproduce, too.

'The vaccine is not just a vaccine, but also a drug,' Zhou said.

...
A virus needs food and amino acids, the building blocks of proteins found in animals and plants, is one source of food. A wild virus will eat almost any amino acid, but the genetically tweaked virus in Zhou’s vaccine would accept only a special kind of man-made amino acid.

The unnatural amino acid can be produced only in a laboratory: it does not exist in the body of animals or humans.
'So after you inject these viruses into the host they will not be able to reproduce themselves due to the lack of a [suitable] amino acid, and they will ‘starve’ to death in the end,' Zhou said."


 

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