Context

Recently, Moderna, the Massachusetts-based American biotechnology company, indicated to begin human trials for a vaccine for HIV (human immunodeficiency virus) in September.

About

What is mRNA, and how do mRNA vaccines work?

• Messenger RNA (mRNA)is expected to work similar to the Covid-19 vaccine — by getting the body’s cells to produce the HIV virus’s spike protein triggering an immune response.
• mRNA provides a recipe that human cells can use to make proteins.
• After injection, the cells in arm muscles pick up the mRNA, make the protein, and display it on the cell's surface.
• Human’s immune system sees the protein and learns how to make an immune response against it.

The Study The study will enroll 56 participants uninfected with HIV. They will be divided into four groups to test the combinations of two versions of the vaccine, called- eOD-GT8 60mer mRNA Vaccine (mRNA-1644) Core-g28v2 60mer mRNA Vaccine (mRNA-1644v2-Core) The participants will receive the doses and will be monitored for adverse effects and signs of immune response after ten months or immunogenicity.

Key-Points

• mRNA-1644 will be the first HIV mRNA vaccine to be trialled in humans. 
• mRNA vaccines tricks the body into producing some of the viral proteins itself.
• They work by using mRNA, or messenger RNA, which is the molecule that essentially puts DNA instructions into action. Inside a cell, mRNA is used as a template to build a protein.
• mRNA-1644, is based on the same mRNA platform as Moderna’s highly effective Covid-19 jab, which is one of two of the only mRNA vaccines to be authorized anywhere in the world. 
• The other is Pfizer-BioNTech’s Covid-19 vaccine.

Collaboration The vaccine is collaboration between Moderna, the International AIDS Vaccine Initiative (IAVI) and the Bill and Melinda Gates Foundation (BMGF).

What are the advantages over other vaccine strategies?

• Safety: Unlike live-attenuated or viral-vectored vaccines, mRNA is non-infectious and poses no concern for DNA integration—mainly because it cannot enter the nucleus, which contains DNA.
• Production: mRNA can be quickly designed and scaled up, if necessary.

Significance

• The quest to develop an HIV vaccine is considered very important for scientific research.
• While treatment with Antiretroviral Therapy has significantly improved the longevity of those with AIDS.
• According to the World Health Organization, there are around 37.7 million living with HIV as of 2020.
• Traditional vaccine approaches have not worked for HIV, and in fact, some of them have gone on to worsen the infection.
• RNA-based immunogens are believed to be a promising alternative because they do not involve the use of a live virus, can be made relatively easily, can be quickly deployed and safely administered.

Challenges

• Of the people living with HIV, over two-thirds are in Africa. Any success in containing the HIV pandemic would mean drastically cutting the rates of transmission there.
• However, as the experience with the Moderna and Pfizer vaccines shows, getting essential jabs to the regions where they are most needed is the biggest stumbling block.
• Another challenge with mRNA vaccines is that they are sensitive to temperature in storage, and is a challenge for developing countries.