Explained: What is a DNA vaccine

NEW DELHI: As the world collectively battles the Covid-19 pandemic, scientists are now looking towards developing a DNA vaccine which can train the human immune system to ward off the infection, before it even takes root.
There are presently various concerns of safety around rollout of vaccines in different countries, and therefore the immunological and logistical benefits of the different vaccines are being examined.
While initial results are yet to show any breakthroughs, many big companies, such as Johnson & Johnson(J&J) are stepping forward to help in driving down the caseloads in the countries.
J&J vaccine uses similar technology tried out on HIV
J&J is developing vaccines using technologies that were previously being tried out on HIV (human immunodeficiency virus).
What's interesting to note here is that while the human immune system doesn't self-cure HIV, it is quite capable of self-curing Covid-19.
J&J vaccine uses similar adenovirus technology to its Covid-19 vaccine, in other words a genetically modified cold virus delivers genetic cargo carrying instructions for the host to develop "mosaic immunogens". These molecules are capable of inducing an immune response to a wide variety of HIV strains.
More people now have access to medications called antiretroviral therapy or ART, which helps keeps down the amount of virus in their body.
This keeps them healthy and unable to transmit HIV to their partners.
Trial results of HIV vaccine candidate expected by end of year
J&J is currently carrying out two human efficacy trials for its HIV vaccine candidate. Initial results from one of the vaccine are expected to be released by the end of this year, said Schuitemaker, the global head of viral vaccine discovery at the firm.
The vaccine candidate is currently being trialed in 2,600 women in sub-Saharan Africa as well.
It's also being tested in around 3,800 men who have intercourse with men and transgender individuals across the US, South America and Europe in the Mosaico trial.

The International AIDS Vaccine Initiative and Scripps Research recently announced results from an early stage trial showing their vaccine candidate stimulated the production of rare immune cells.
Vaccines, such as the Novavax is protein-based and works by eliciting antibodies that bind to the virus' spike protein and stops it from infecting other human cells.
This is needed as a first step in the process of inducing 'broadly neutralising antibodies' or bnAbs. The range of antibodies should then provide better protection, as well as protect someone from the different variants.
Currently, they are partnering with Moderna to develop a messenger ribonucleic acid (mRNA) and are hopeful that the mRNA technology, which turns the body's cells into vaccine factories can make the difference.