HIV vaccine

Subject: Science

Section: Biotechnology

Context: HIV vaccine development has taken a back seat

Current status of the HIV disease burden in India

There are an approximate 2.3 million people living with HIV (PLHIV) in India.
Of these 76% know their HIV status. Of those aware of their status, 84% are on antiretroviral treatment (ART).
Among those on ART, the virus has been suppressed in 84% cases.
New HIV infections in India have declined by 37% between 2010 and 2019 compared to the global average of 23%.
Similarly, during the same period, AIDS-related deaths have declined in India by almost 66% against the global average of 39%, according to the NACO report of 2020.
The decline is higher in states like Andhra Pradesh, Maharashtra, Karnataka, Telangana, Tamil Nadu and West Bengal and noticeably among women and children at 73.7% and 65.3% respectively.
Despite commendable progress, Mizoram (2.32%), Nagaland (1.45%), and Manipur (1.18%) had higher than 1% HIV prevalence in the adult population in 2019.

Vaccines against HIV

Currently, all are candidate vaccines because there is no finished product which has been commercialized or licensed for human usage.
Broadly, here are two types of vaccines: One for those who are HIV negative, termed a preventive vaccine or immunoprophylaxis.
The other one is for PLHIV, to prevent disease progression to clinical stages and that is called a therapeutic vaccine or immunotherapy, akin to treatment.
There has been a lot of progress in this area after the success of long-acting antiretrovirals, Cabotegravir and Rilpivirine, where the PLHIV needs to be treated with a monthly or bimonthly injectable rather than daily oral medicines.
After the COVID vaccine success story, there are two specific COVID vaccine platforms, which can be used for HIV – an mRNA and DNA one.
Broadly neutralizing antibodies (BNAbs) are produced by certain types of B immunity cells, which are rare. Maybe only one in 300,000 B cells have this capability.
The mRNA vaccine aims to stimulate production of bnAbs that can act against many variants of HIV.
So, the mRNA vaccine will instigate B-cells and try to produce more neutralizing antibodies.

Challenges with HIV vaccines

With no commercial vaccine in 35 years, there are very few companies and research laboratories which would invest in vaccine development.
Moreover, with a very high success rate of ART in India, HIV vaccine development has taken a back seat.
Even if candidate vaccines against HIV are found successful in phase 2 and can be taken forward to phase 3 of trials, the chances of getting emergency use authorisation or listing are less as HIV is no more an emergency.