Battling a deliberately-acquired infection to help find a cure

Battling a deliberately-acquired infection to help find a cure

Subject :Science and technology

Section: Health

Context:

Researchers at the University of Maryland had conducted a “controlled human infection study” (CHIS), also called a human challenge study to test a new vaccine that one day may hopefully prevent Shigellosis.

Details:

• A CHIS is a relatively quick and efficient way to assess if a vaccine might work.
• India is likewise considering introducing CHIS.

ICMR’s proposal for CHIS:

• CHIS is a research model that intentionally exposes healthy volunteers to pathogens under controlled conditions.
• The CHIS is proposed by the Indian Council of Medical Research’s (ICMR) Bioethics Unit.
• Outside of India, this relatively new research model which involves intentionally exposing healthy volunteers to pathogens in a controlled environment, has been used to study malaria, typhoid, dengue, etc.
• The deterrents include technical, clinical, ethical and legal contentions, amid unique socio-cultural context.
• Concerns include:
  • India has so far stayed away from CHIS, because regardless of the potential scientific benefits, these studies are ethically sensitive and raise concerns about contentious research ethics issues like:
    • deliberate harm,
    • possible disproportionate payment and hence inducements,
    • third-party risk,
    • withdrawal from the study and research with vulnerable participants.

Need for the CHIS:

• India carries a high burden of morbidity and mortality from infectious diseases.
• They contribute about 30% of the disease burden in the country.
• Finding novel, efficient, and cost-effective alternatives to existing methods of research in these diseases and their prevention is imperative to reduce this burden.
• CHIS helps provide unique insights into disease pathogenesis and can accelerate the development of novel medical interventions.
• CHIS offers accelerated, cost-effective, and efficient outcomes using smaller sample sizes in comparison to large clinical trials.
• Its social value includes:
  • potential contributions to public health response to diseases of concern,
  • healthcare decision-making,
  • policies and economic benefits,
  • improved pandemic preparedness, and
  • community empowerment.
• ICMR has also cautioned that CHIS is a highly complex area and may require collaborations at different levels between researchers, institutions, organisations and/or between different countries.

What is the fundamental difference between human clinical trials and human challenge studies?