The world's first new crown DNA vaccine approved: 67% effective against Delta strain

Article source: Medical Rubik's Cube Pro

Author: Haimer

According to a report by Nature on September 2, the Indian drug regulatory agency approved the world's first DNA vaccine ZyCoV-D to prevent new crown infections in people 12 years and older
.

In a large-scale clinical trial involving 28,000 people, the vaccine has an effective rate of 67%

ZyCoV-D was developed by the Indian pharmaceutical company Zydus Cadila and does not require injection
.

The needle-free device pressed on the skin uses a small flow of high-pressure liquid to pierce the skin, making it less painful than injection

DNA vaccines contain circular DNA that encodes antigenic information, which is commonly referred to as a "plasmid
.

" After the plasmid enters the human nucleus, it is transcribed into mRNA and then translated into antigen protein in the cytoplasm

In contrast to mRNAs that do not need to enter the nucleus and can be directly translated into antigenic proteins in the cytoplasm, the challenge of DNA vaccines lies in the first step of transcription
.

In previous clinical trials, DNA vaccines were difficult to induce a strong immune response in the body, so they were only used in veterinary vaccines

DNA vaccines also have their unique advantages
.

Compared with mRNA vaccines, DNA vaccines have greatly improved stability and are easier to mass produce

Regarding the vaccine effectiveness 67% lower than the mRNA vaccine, the researchers said that the two are not comparable
.

When the effectiveness test of the DNA vaccine was carried out at the beginning of this year, the epidemic strain was already a variant of Delta

Unlike mRNA vaccines that use lipid nanoparticles (LNP) for in vivo delivery, DNA vaccines are usually delivered using electroporation devices
.

Under the action of the electric field, human cells instantly open the cell pores, and the plasmid enters the cells efficiently through the pores; as soon as the electric field disappears, the cell pores will be closed and restored immediately

Zydus Cadila said that the vaccine will be vaccinated in India in September this year, and it is expected to achieve a production capacity of 50 million doses early next year
.

At present, Zydus Cadila has not announced the results of the later clinical trials of the vaccine, and some researchers have expressed doubts about it

In addition, the vaccine requires at least 3 injections to protect it
.
During the COVID-19 pandemic, it has brought no small logistical challenges
.

Domestically, Ai Di Weixin has stated that the new crown DNA vaccine cooperating with Inovio will complete phase III clinical trials within this year and is expected to be approved for marketing in the second half of the year
.

Note: The original text has been deleted

Reference materials:

[1] Smriti Mallapaty, India's DNA COVID vaccine is a world first – more are coming.
Nature.
(2021).

[2] Ai Di Weixin founding scientist Wang Bin: Prepare for thirty years, the DNA vaccine is ready (Source: Medical Rubik's Cube)

[3] Interview | The world's first new crown DNA vaccine is expected to be available within this year, and Ai Di Weixin RSV vaccine will enter clinical phase II (Source: DeepTech)