Efforts are in full swing all over the world to find an effective vaccine for coronavirus. Though a similar effort to find a vaccine for HIV (Human Immunodeficiency Virus), which wrecked havoc in the 1990s and early 20th century, has not met with success so far, an effective and affordable antiretroviral treatment (ART) has transformed HIV/ AIDS (Acquired Immune Deficiency Syndrome) from a “death sentence” to a chronic, manageable disease. Speaking to The Sunday Guardian, RAJAT GOYAL, the Country Director of International AIDS Vaccine Initiative (IAVI), a global organisation working to accelerate development of effective AIDS vaccines, talked about the challenges in treatment of HIV/AIDS.
Q: What is the current status of HIV/AIDS in India and the world?
A: As per UNAIDS, 37.9 million people globally were living with HIV (end 2018) and HIV/AIDS kills 770,000 people every year. Despite advances in treatment and prevention, about 1.7 million people contract HIV every year. In India, as per estimates, 2.1 million people were living with HIV (end 2018). However, it is important to note that globally, the incidence of new HIV infections has been reduced by 40% since its peak in 1997 and AIDS-related deaths have declined by more than 56% since 2004. In India, the National AIDS Control Organisation (NACO) has been successful in running multiple programmes, including targeted interventions and IEC interventions, which remain committed to behaviour change. In addition to this, planned scale-up and accessibility to Anti-Retroviral Treatment and Testing has led to decline in HIV/AIDS cases. However, treatment alone is not enough; we need new ways to stop HIV transmission and support treatment and cure. Vaccines are the most powerful public health tools available which have stood the test of time in proving their mettle to eradicate global public health problems like smallpox, polio, etc. A preventative vaccine for HIV would be equally powerful.
Q: What is the status of the various efforts going on to come out with a vaccine for the syndrome? Do you think there could be a breakthrough in the near future?
A: While it is difficult to commit to a timeline for development of a vaccine, there is a lot of work that is going on to design a vaccine. Researchers are focussing on two kinds of vaccines—preventative vaccine, which would teach our immune system to spot the virus (once the body is exposed e.g. right after sexual intercourse) and stop it from spreading infection, and the other is therapeutic vaccine, which in theory can act as a supplement for antiretroviral treatment (ART), helping control the spread of virus. It is important to understand that no therapeutic HIV vaccine has been proven to work yet. Also, there is no HIV preventative vaccine which has been licensed yet, and potential candidates are under trial. One of the large scale studies currently going on in Africa is for a global HIV vaccine to check whether it is effective against most HIV strains, something we call a “mosaic vaccine”. There is another Phase IIb clinical trial planned for 2020 that will test two combination regimens, each containing multiple clades. In addition to this, the world is eagerly looking forward to the results from Antibody Mediated Prevention (AMP) study that tests whether antibodies can prevent HIV infections in people. Also, we cannot forget the insights we learnt from the recently closed HVTN-702 study which was trying to improve upon the vaccine trial done in Thailand in 2009, where we first time learnt that the vaccine provided 30% protection against HIV. Despite all these efforts, it is hard to say when a vaccine would be available, but we remain committed to finding a vaccine and we are going to keep improving the interventions as we work towards developing one.
Q: What is the reason for the delay in getting a vaccine for HIV/ AIDS?
A: Developing a vaccine to prevent HIV/AIDS is one of the most challenging problems ever for vaccine development. HIV is one of the most complicated viruses ever identified. It targets and destroys the very immune system that a vaccine traditionally triggers, and the genetic diversity of the virus is one of the key challenges faced by scientists as this virus mutates really fast as it moves from person to person and multiple recombinant strains. There are other scientific challenges to AIDS vaccine development, including the lack of a fully adequate model for early testing of candidates in animals. There are questions of what the most effective approach or combination of approaches will be to be triggering an immune response to HIV: cellular, humoral or mucosal. And finally, it is yet unknown whether a single universal vaccine can create immunity against the different subtypes, or clades, of the HIV virus, or if a different vaccine must be developed against each clade.