Author Tang Yichen zycov-d is the first DNA vaccine approved for human use in the world.
Photo source: ZydusCadila recently, India approved a novel coronavirus vaccine, ZyCoV-D, which uses a circular DNA chain that stimulates the immune system to fight COVID-19.
As the world’s first DNA vaccine for human, zycov-d has been approved, which indicates the arrival of DNA vaccines for various diseases.
The website of Nature reported that zycov-d can enter the skin without needle injection.
Researchers found in clinical trials that its protection rate for symptomatic novel coronavirus patients is 67%, or it will be used in India this month.
The researchers said that although its effectiveness is not particularly high compared with many other novel coronavirus vaccines, it is of great significance as a DNA vaccine itself.
The novel coronavirus pneumonia, University of Western Australia, PeterRichmond, says this proves that DNA vaccine is effective and helps control the novel coronavirus pneumonia pandemic.
“This is a very important step forward in the global fight against the novel coronavirus, because it shows that we have another kind of vaccine to use,” he said.
At present, nearly 12 new DNA crown vaccines are undergoing clinical trials all over the world, and at least as many vaccines are in the early stage of development.
DNA vaccines for many other diseases are also under development.
Shahid Jameel, a virologist at the University of Ashoka in India, said, “if DNA vaccines prove successful, this will be the future of vaccinology because they are easy to manufacture.” David Weiner, director of the vaccine and immunotherapy center of the westa Institute in Philadelphia, Pennsylvania, said that the urgency of fighting the novel coronavirus has accelerated the development of vaccines using genetic technology, Such as messenger RNA vaccine and DNA vaccine.
In clinical trials, RNA vaccine can show a strong immune response faster.
But DNA vaccines also have many advantages.
They are easy to produce and the finished products are more stable than messenger RNA vaccines, which usually need to be stored at very low temperatures.
Zycov-d was developed by zydus Cadila, an Indian pharmaceutical company headquartered in Ahmedabad.
Recently, the Indian drug regulatory authority approved the vaccine for people over the age of 12.
67% of the effectiveness figures came from clinical trials involving more than 28000 participants.
In the trial, there were 21 symptomatic novel coronaviruss in the vaccinated group and 60 in the placebo group.
ZyCoV-D contains a circular DNA chain called plasmid, which can edit COVID-19 spike protein and promoter sequence of promoter genes.
Once plasmids enter the nucleus, they are transformed into messenger RNA, which reaches the cytoplasm, the main body of the cell, and is translated into spike protein itself.
Then, the human immune system responds to this protein and produces tailored immune cells to eliminate future infections.
Plasmids usually degrade within weeks to months, but immunity still exists.
The challenge of DNA vaccines is that they need to reach the nucleus, while messenger RNA vaccines only need to reach the cytoplasm, Jameel said.
Therefore, for a long time, DNA vaccine has been difficult to induce effective immune response in clinical trials, which is why so far, DNA vaccine has only been approved for animals, such as horses.
Zycov-d solves this problem well.
It is deposited under the skin rather than deep in muscle tissue.
The subcutaneous area is rich in immune cells, which can swallow foreign objects, such as vaccine particles, and treat them.
The vaccine is injected by pressing a needle free device on the skin, which produces a subtle flow of high-pressure liquid that pierces the skin surface with less pain.
Zhao Lu typesetting Zhi Hai, editor of China Science Daily (1st edition, September 6, 2021).