Human Trials for a HIV Vaccine

In News

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

About

  • The study will enrol 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) and 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.
  • This is the first trial for an mRNA vaccine for HIV.
    • After the success of mRNA vaccines with Covid-19, vaccines against HIV are thought to hold a lot of promise.

 

 

Messenger RNA (mRNA)

  • It is a single-stranded RNA molecule that is complementary to one of the DNA strands of a gene.
  • The mRNA is an RNA version of the gene that leaves the cell nucleus and moves to the cytoplasm where proteins are made.
  • During protein synthesis, an organelle called a ribosome moves along the mRNA, reads its base sequence, and uses the genetic code to translate each three-base triplet, or codon, into its corresponding amino acid.

 

How the vaccine works

  • The vaccine 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.
  • In the preliminary Phase 1 results released earlier this year, the International AIDS Vaccine Initiative (IAVI) and Scripps Research announced that the candidate molecule used in this vaccine was able to produce the expected immune response by activating a group of cells called naive B cells.
    • B cells are a class of white blood cells that produce antibodies that can bind to invading bacteria and viruses.
  • These immune cells have not yet been activated as they have not been exposed to an antigen or foreign body before.
  • The activation of these cells eventually resulted in the generation of strong proteins called broadly neutralising antibodies (bNAbs), which are known to neutralise the fast-mutating and highly diverse HIV virus.

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.

 

Conclusion

A drawback of mRNA vaccines used to be their instability.

  • However, the experience with the coronavirus vaccine has come as a shot in the arm. The success of mRNA vaccines — Pfizer -BioNTech and Moderna — in reducing hospitalisation and mortality has led to confidence in the method.

About Human immunodeficiency virus (HIV)

  • It is an infection that attacks the body’s immune system, specifically the white blood cells called CD4 cells.
  • HIV destroys these CD4 cells, weakening a person’s immunity against infections such as tuberculosis and some cancers.
    • If the person’s CD4 cell count falls below 200, their immunity is severely compromised, leaving them more susceptible to infections. Someone with a CD4 count below 200 is described as having AIDS (acquired immunodeficiency syndrome).
  • HIV can be diagnosed using simple and affordable rapid diagnostic tests, as well as self-tests.
  • It is important that HIV testing services follow the 5Cs: consent, confidentiality, counselling, correct results and connection with treatment and other services.
  • This early identification greatly improves treatment options and reduces the risk of transmission to other people including sexual or drug-sharing partners.

Symptoms:

  • Many people do not feel symptoms of HIV in the first few months after infection and may not know that they are infected.
  • Others may experience influenza-like symptoms, including fever, headache, rash and sore throat. However, these first few months are when the virus is most infectious.
  • As the disease progresses, symptoms will be expanded and more pronounced.
  • These can include swollen lymph nodes, weight loss, fever, diarrhoea and cough.

Treatment /Prevention:

  • HIV is fully preventable: Effective antiretroviral treatment (ART) prevents HIV transmission from mother to child during pregnancy, delivery and breastfeeding.
  • HIV is treated with antiretroviral therapy consisting of one or more medicines.
  • ART does not cure HIV but reduces its replication in the blood, thereby reducing the viral load to an undetectable level.
  • ART enables people living with HIV to lead healthy, productive lives.
    •  It also works as effective prevention, reducing the risk of onward transmission by 96%.
  • ART should be taken every day throughout the person’s life. People can continue with safe and effective ART if they adhere to their treatment.
  •  In cases when ART becomes ineffective due to reasons such as lost contact with health care providers and drug stock outs, people will need to switch to other medicines to protect their health.
  • Someone who is on antiretroviral therapy and virally suppressed will not pass HIV to their sexual partners.
  • Condoms prevent HIV and other sexually transmitted infections, and prophylaxis use antiretroviral medicines to prevent HIV.
  • Male circumcision is recommended in high-burden countries in eastern and southern Africa.
  • Harm reduction (needle syringe programmes and opioid substitution therapy) prevents HIV and other blood-borne infections for people who inject drugs.

Global Efforts:

  • UNAIDS: The Joint United Nations Programme on HIV/AIDS  (UNAIDS) is an international organization that is working towards stopping new HIV infections, ensuring that everyone living with HIV has access to HIV treatment, promoting human rights, and producing data for decision-making.
    • The organization leads and inspires the world to achieve its shared vision of zero new HIV infections, zero discrimination and zero AIDS-related deaths.

 

  • WHO recommends that every person who may be at risk of HIV should access testing.
    • People diagnosed with HIV should be offered and linked to antiretroviral treatment as soon as possible following diagnosis. If taken consistently, this treatment also prevents HIV transmission to others.

Steps Taken by India

  • HIV/AIDS Act 2017:
    • The Human Immunodeficiency Virus and Acquired Immune Deficiency Syndrome (Prevention and Control) Act, 2017, came into force on September 10, 2018.
    • It aims to prevent and control the spread of HIV and AIDS in the country and provides for penalties for discrimination against those affected by the virus.
    • It provides a legal and enabling framework to safeguard the human rights of infected and affected populations.
  • 90-90-90 Strategy:
    • 90% of those who are HIV positive in India know their status, 90% of those who know their status are on treatment and 90% of those who are on treatment experience effective viral load suppression.
  •  HIV Prevention Model:
    • India’s unique HIV prevention model is centred around the concept of ‘Social Contracting’ through which the ‘Targeted Interventions Program’ is implemented with support from civil society. The program is aimed at behaviour change, communication, outreach, service delivery, counselling & testing and ensuring linkages to HIV care.
  • Free Anti-Retro-Viral Treatment
    • India is providing free antiretroviral treatment to close to 1.4 million people. Indian drugs are also reaching millions of People living with HIV in Africa.
  • National AIDS Control Programme (NACP):
    • It was launched in 1992, is being implemented as a comprehensive programme for the prevention and control of HIV/AIDS in India. Over time, the focus has shifted from raising awareness to behaviour change, from a national response to a more decentralized response.
    • It has been Revised, Revived and Revamped to focus on hard-to-reach and at-risk populations.
    • In line with the motto of the Government of India, ‘Together, for everyone’s growth, with everyone’s trust’, the National AIDS Control Program has signed MoUs with public and private sector industries to mobilise their support for HIV prevention and treatment.
  • Viral Load Testing Facilities:
    • They have been scaled up, and HIV counselling, testing and community-based screening for early diagnosis have been ramped up to achieve the target of Elimination of Mother to Child Transmission of HIV.
  • Project Sunrise:
    • It was launched by the Ministry of Health and Family Welfare (2016) to tackle the rising HIV prevalence in northeastern states.

Source :TH