Controlled Human Infection studies (CHIS)

By

Controlled Human Infection studies (CHIS) refers to the research methodology that involves intentionally exposing healthy human volunteers to a specific pathogen or infectious agent under controlled conditions. These studies aim to understand disease pathophysiology & immune responses, develop vaccines, test treatment modalities and evaluate the safety and efficiency of potential New Chemical Entities (NCE). In contrast to natural infection studies, which can take longer to observe, researchers obtain data more quickly and efficiently from controlled studies as they involve infecting selected healthy participants under stringent standard protocols. Furthermore, CHIS offers the advantages of accurate observations, comparison and generalization of data as various variables (dose, timing of pathogen exposure etc.) can be modulated. Common types of CHIS include challenge studies, vaccine development trials and treatment studies. Challenge studies involve intentionally infecting healthy volunteers with a controlled strain and a controlled dose to study its host-pathogen interaction, transmission dynamics and potential alternativesto existing interventions. Human challenge studies can accelerate vaccine development by aiding in vaccine selection, by understanding cross-protective immunity, immune correlates & protective mechanisms and by evaluating biologics/ vaccines, while exposing only a small group of volunteers. In comparison to conventional drug trials, CHIS model of assessing the efficacy of drugs may pose a lower risk as these studies use attenuated pathogens to test therapeutic drugs in a controlled environment. 

Regardless of the potential scientific benefits, these studies are ethically sensitive and raise concerns about contentious research ethics – such as issues like deliberate harm, possible disproportionate payment and hence inducements, third-party risk, withdrawal from the study and research with vulnerable participants. Hence these studies need a streamlined ethics review process with additional ethical oversight and safeguards to protect the study participants.

Need for CHIS in India:

India carries a high burden of morbidity and mortality from infectious diseases. Infectious disease contributes about 30% of the disease burden in the country. Finding novel, efficient, and cost-effective alternativesto existing methods of research in these diseases and their prevention isimperative to reduce  this burden. CHIS is a relatively a new research model that helps provide unique insights into disease pathogenesis and can accelerate the development of novel medical interventions. Though many  countries have conducted CHIS research on various infectious diseases such as malaria, influenza, dengue fever, typhoid and cholera, India is yet to conduct CHIS. The deterrents include technical, clinical, ethical and legal contentions, amid unique socio-cultural context. 

Some potential benefits to conducting CHIS research in India include: 

a. Conducting these studies in endemic settings can lead to outcomes relevant to the local population as the participants from endemic areas share similar immunity patterns, associated co-infections, existing pharmacogenomic data, environmental factors, nutrition etc. 

b. Vaccine Research uses data related to immune responses in early vaccine development. In CHIS this is achieved by exposing pathogens to only a limited number of participants. Researchers can also assess vaccine efficacy and determine the minimum required dose for protection and immunization in shorter time frames. 

c. Researchers can closely monitor the development and progression of an infectious disease from its earliest stages - including symptoms, incubation periods and immune responses -which improves their understanding of the disease. These insights can lead to improved diagnostic methods, treatments and drug development. 

d. CHIS can improve understanding of specific aspects of the transmission patterns and/or excretion and/or secretion patterns and dynamics that contribute to the development of effective public health strategies and policies. 

e. Conducting CHIS can contribute towards building local research capacities, clinical facilities, laboratory diagnostics, experimental medicine and clinical governance on par with global initiatives on this subject.

ICMR

Comments

Post a Comment

Popular posts from this blog

Russian parliament passed a bill to revoke its ratification of the Comprehensive Test Ban Treaty

By
Relevance:  Russia revokes ratification of nuclear test ban treaty (CTBT) - ICAN But it affirmed that it will  retain its cooperation with the treaty’s verification system and implementing organisation.  Comprehensive Test Ban Treaty: The Comprehensive Test Ban Treaty (CTBT), which opened for signature in 1996, was intended to prohibit all nuclear weapon test explosions. Over 2,000 nuclear tests occurred between 1945 and 1996: the United States (1,000+), the Soviet Union (700+), France (200+), the United Kingdom and China (45 each). As at January 2013, 183 countries had signed the Treaty, of which 158 have also ratified it, including three of the nuclear weapon states (France, the Russian Federation and the United Kingdom). However, 44 specific nuclear technology holder countries must sign and ratify before the CTBT can enter into force. Of these, eight are still missing: China, Egypt, India , Iran, Israel, North Korea, Pakistan and the US. India , North Korea and Pakistan have yet to
Read more

Interstellar space and Interstellar Probes ( Voyager and New Horizons Missions )

By
Interstellar Space: Interstellar space is often called the space between the stars, but more specifically, it’s the region between our Sun’s heliosphere and the astrospheres of other stars. Our heliosphere is a vast bubble of plasma – a gas of charged particles – that spews out of the Sun. This outflow is known as the solar wind. The bubble surrounds the Sun and stretches beyond the planets. Both Voyager spacecraft had to travel more than 11 billion miles (17 billion kilometers) from the Sun in order to cross the edge of the heliosphere. This bubble is moving through interstellar space as the Sun orbits the center of the Milky Way galaxy. As our heliosphere plows through space, it creates a bow wave, like the wave formed by the bow of a ship. Kuiper Belt &  Oort Cloud: The Kuiper Belt is a doughnut-shaped ring of icy objects around the Sun, extending just beyond the orbit of Neptune from about 30 to 55 AU. Similar to the asteroid belt, the Kuiper Belt is a region of leftovers from
Read more

UPSC IAS Daily Current Affairs ( 05 - 12 - 2023 ) by UniFocus IAS

By
Net-Zero Export Credit Agencies Alliance (NZECA) launched at COP28 India Internet Governance Forum IIGF’23 to be held in New Delhi tomorrow JT-60SA: The World's Biggest Nuclear Fusion Reactor starts operation ITER ( International Thermonuclear Experimental Reactor ) Basics of Nuclear Energy ( Articles by The International Atomic Energy Agency ( IAEA )) What is Nuclear Energy? The Science of Nuclear Power  What is Nuclear Fusion? Basic fusion physics Fusion - Frequently asked questions What is Fusion, and Why Is It So Difficult to Achieve? Safety in Fusion Fusion - International Collaboration Nuclear Fusion Basics
Read more