By DR. KHURSHID AHMAD TARIQ
World AIDS day is celebrated by the WHO in partnership with UN member states on December 1st every year since 1988 to provide an opportunity to people worldwide to unite and financially support the fight against HIV/AIDS. This year is the thirty years of world AIDS day labelled as WAD30 and celebrated under the theme “Know Your Status” because one in four people with HIV don’t know they have it. Therefore, to know the risks and the personal status is imperative to all. The 2018 campaign is about raising awareness and donating money at the level of community, social media, schools, colleges and universities or at other work places with the slogan “Rock The Red Ribbon” to support HIV affected people and their families. The celebration of world AIDS day assumes much of the importance and significance to remind the government, people, community and other organisations/agencies to increase awareness, promote sex education, improve health care, support the affected people, stabilise their family and social status and promote the preventive measures because most of the people ignorantly do not actually know the facts how they get the human HIV infection and how to protect themselves.
Cause, transmission and effects: AIDS is a deadly disease caused by the infection of human immunodeficiency virus (HIV) bestowed with reverse transcriptase enzymatic activity. The known ways of HIV transmission from infected to naïve cases are unprotected sexual contacts, receiving unsafe blood transfusion or any sort of blood contact, exposure to contaminated injecting equipment and mother to child transmission. Although AIDS is purely a viral disease, it has great immunological implications. Its normal host cell in the human body is a T cell (major cell being the helper T cell or CD4 cell) which loses the property of proliferation to form cytotoxic T-cells(indispensable for cell mediated immunity in a normal individual) after being infected. This phenomenon is the prime cause of putting the host at risk of secondary and opportunistic infections wherein a patient becomes immunodeficient (severe decline in CD4 cells) to deal with infections.
Besides, cells of central nervous system and macrophages of various body tissues including blood are also infected. The virus actively multiples, infects and ultimately destroys immune cells. The symptoms may appear within months or years after infection with sparse reduction in CD4 cells. So, immune system dysfunction is the prime cause of AIDS with development of certain opportunistic infections (like TB, pneumonia, encephalopathy, candidiasis, and toxoplasmosis) and several cancers (lymphomas, cervical carcinoma, Kaposi’s sarcoma) and persistent diarrhoea and fever. Multi drug resistant TB continues to be a major issue in AIDS patients worldwide.
Current treatments and future prospects: As of now, the drugs and anti HIV agents approved for treatment are reverse transcriptase inhibitors (azidothymidine, dideoxyinosine, dideoxycytidine, lamivudine) which have increased the survival chances of patients by delaying the onset of opportunistic infections. Secondly, the other category of drugs called as protease inhibitors (saquinavir, indinavir, ritonavir) don’t allow the capsid production in new HIV particles synthesised in host cells. However, the more effective treatment is the combination of these inhibitors called as highly active antiretroviral therapy (HAART), which has significantly helped in reducing the AIDS deaths worldwide. Similarly fusion inhibitors (Enfuvirtide) have proved very effective in combination with HAART by blocking the viral entry into CD4 cells (by preventing the fusion of viral envelope with the plasma membrane of CD4 cell). Despite these novel and effective treatment measures, globally 36.7 million people have the HIV infection and more than 35 million infected people have died already. In J&K alone, 4609 HIV positive cases were reported and 980 people have died because of HIV infection (Source: J&K State AIDS Control Society).
Two kinds of HIV vaccines are, at present, being evaluated in animal and human models. A preventive vaccine (immune system will recognise and fight off HIV before the virus causes infection) and a therapeutic vaccine (it will help control infection and delay the progression of the disease). The safety and effectiveness of vaccination against AIDS is quite debatable and vaccine use is predicted to be risky because the active virus may be present in the inactivated whole HI viruses. However, vaccine either inactivated whole virus or synthetic viral fragments (gp41 & gp120) based on various subtypes to protect susceptible individuals is the future promise to cure AIDS and is being tested in various animal models and some human volunteers.
Despite tremendous achievements made in the vaccine development for the last more than twenty years, it is still in an experimental regimen. The emphasis is on designing a mosaic vaccine to induce immune responses against a wide variety of global HIV strains and has shown promising advancements for the final clinical trials in humans with thrust on use of neutralising antibodies against HIV epitopes. Quite recently Scientists from China have claimed to have removed the doorway through which the HIV enters the immune cells by developing HIV resistant twin girls born to a couple who volunteered to produce designer babies by using the much debated technique of human gene editing called CRISPR-cas9. It is a ground breaking move in the history of AIDS treatment, however, open to ethical implications in presence of the ban in editing human embryos except for research purposes with strict regulatory approval.
To conclude, AIDS is a deadly disease with major health problems and issues worldwide and prevention is the only better option available as of now despite tremendous achievements in understanding its infection, pathogenicity and possible treatments through HAART, vaccination and gene therapy.
The author is an Assistant Professor of Zoology at the Islamia College of Science & Commerce, Srinagar. He can be reached at: firstname.lastname@example.org