- May 20, 2022
- Posted by: admin1
- Category: DPN Topics
Context: HIV vaccine development has taken a back seat
- With antiretroviral therapy, HIV has become a chronic but manageable disease.
- Still there are challenges that need to be tackled to eliminate AIDS by 2030.
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.