mRNA vaccines are considered to be the future of vaccinology due to their high efficiency, safety, high production efficiency, and low cost. It is also based on the excellent performance of mRNA vaccines that the market values of mRNA vaccine developers Moderna and BioNTech reached US$160 billion and US$80 billion, respectively.
We all know that mRNA is responsible for transmitting the genetic information stored in DNA and directing protein synthesis in cells. mRNA can be used as a vaccine, so can DNA, which is more stable than mRNA, be used as a vaccine?
In fact, more than 10 DNA COVID-19 vaccines are currently in clinical trials around the world.
The First DNA Vaccine
A few days ago, India has granted emergency authorization for the marketing of a DNA COVID-19 vaccine. This is the world's first DNA COVID-19 vaccine and the world's first DNA vaccine. This is a milestone in the history of DNA vaccine research and development, and there may be more DNA vaccines available in the future.
This DNA COVID-19 vaccine is called ZyCoV-D and was developed by Zydus Cadila in India. Unlike other COVID-19 vaccines, this vaccine does not require needle injection, but is administered through a needle-free device that generates a small high pressure. The fluid directly penetrates the surface of the skin, eliminating the pain of needle sticks.
DNA Vaccines Against COVID-19 Are Currently Undergoing Clinical Trials Around The World
Will DNA vaccines be the future of vaccinology?
Since the 1990s, both DNA vaccines and mRNA vaccines have been under development. However, the challenge for DNA vaccines is that it needs to enter the nucleus to be transcribed into mRNA, while mRNA vaccines don’t have to go into the nucleus, they only need to enter the cytoplasm to be directly translated. Therefore, for a long time, DNA vaccines have been difficult to induce effective immune responses in clinical trials, which is why DNA vaccines have only been approved as animal vaccines before.
It is known that the DNA used in the ZyCoV-D vaccine is a circular DNA strand, which encodes the spike protein (S protein) of the COVID-19 and a promoter sequence that initiates gene expression. After the circular DNA enters the nucleus, it will be transcribed into mRNA, and then returned to the cytoplasm and translated into spike protein (S protein), which causes the body's immune response.
The Indian drug regulatory agency urgently authorized the approval of the ZyCoV-D vaccine for vaccination of people aged 12 years and over. Based on a large-scale clinical trial of about 28,000 people, the protection rate of the ZyCoV-D vaccine was 67%, although the protection rate was not as good as that two mRNA vaccines have been approved, but it should be pointed out that the high protection rate of more than 90% of the two mRNA vaccines is against the early version of the COVID-19, while the 67% protection rate of the ZyCoV-D vaccine is mainly for Delta Variant.
As the first DNA vaccine, ZyCoV-D vaccine shows that we have a new type of vaccine. In addition, compared to mRNA vaccines, DNA vaccines are easier to produce and store. Once their effects are proven, DNA vaccines may become the future of vaccinology.
DNA is easier to synthesize than mRNA, so it is easier to produce and lower in cost, and DNA is more stable, so it is easier to store and transport. mRNA vaccines usually need to be stored at -80°C, while DNA vaccines can be stored at room temperature. DNA vaccines can be stable for more than 1 year at room temperature, and can be stored at standard refrigeration temperatures (2°C-8°C) for 5 years, while mRNA vaccines can only be stored for 5 days under standard refrigeration conditions.
Both mRNA vaccines and DNA vaccines are milestone successes in preventing COVID-19, and they will make a huge contribution to public health. Biopharma PEG supplies mPEG-N,N-Ditetradecylacetamide (ALC-0159), mPEG-DMG, mPEG-CH2CH2CH2-NH2, mPEG-OH, mPEG-CM (mPEG-AA), mPEG-DSPE and mPEG-DPPE that can be used in COVID-19 vaccines.
India's DNA COVID vaccine is a world first – more are coming