Syllabus: GS3/Science and Technology
Context
- Researchers have developed an experimental therapy called CRMA-1001, which aims to silence the DNA of the Hepatitis B virus rather than directly destroying the virus.
- Scientists are exploring a novel approach to treat Hepatitis B using epigenetics.
What is Epigenetics?
- Epigenetics is the study of how cells control gene activity without changing the DNA sequence.
- Epigenetic changes are modifications to DNA that regulate whether genes are turned on or off.
- These modifications are attached to DNA and do not change the sequence of DNA building blocks.
- A common type of epigenetic modification is called DNA methylation.
- It involves the attachment of methyl groups to DNA building blocks.
- When methyl groups are present on a gene, that gene is turned off or silenced, and no protein is produced from that gene.
- Errors in the epigenetic process, such as modification of the wrong gene or failure to add a chemical group to a particular gene or histone, can lead to abnormal gene activity or inactivity.
Gene Therapy
- It is a technique that uses genes to treat, prevent, or cure diseases by:
- Replacing faulty genes,
- Deactivating harmful genes,
- Introducing new genes to restore health.
- Methods of Gene Therapy:
- Somatic Cell Gene Therapy involves the insertion of therapeutic genes into non-reproductive (somatic) cells. The changes are not heritable and are limited to the individual receiving the treatment.
- Germline Gene Therapy targets reproductive cells such as sperm or eggs, leading to heritable genetic changes. However, due to ethical and safety concerns, this type of therapy is currently banned in most countries, including India.
What is a Functional Cure?
- A functional cure refers to sustained suppression of a virus to the extent that it no longer causes active disease, even though some viral genetic material may remain in the body.
- In Hepatitis B, the viral DNA can persist in liver cells even when the infection is clinically suppressed.
- Existing treatments can control viral replication but rarely eliminate the persistent viral DNA.
- CRMA-1001 aims to silence this remaining viral DNA and prevent the virus from becoming active again.
What is Hepatitis?
- Hepatitis is an inflammation of the liver, there are five main strains of the hepatitis virus, referred to as types A, B, C, D and E.
- Types B and C lead to chronic disease and together are the most common cause of liver cirrhosis, liver cancer and viral hepatitis-related deaths.
- Hepatitis A: It is caused by the Hepatitis A Virus (HAV). It does not cause chronic infection and is usually self-limiting.
- It spread through contaminated food and water (fecal–oral route).
- It is entirely preventable where vaccines offer protection rates exceeding 90 to 95%.
- Hepatitis B: Hepatitis B is known to cause acute infection, liver failure happens in severe cases.
- Spread: Spread through blood and body fluids, sexual contact, mother-to-child transmission.
- Treatment: Hepatitis B can be prevented with a vaccine, providing nearly 100% protection against the virus. The vaccine is usually given soon after birth with boosters a few weeks later.
- Hepatitis C: The severity from a mild illness to a serious, lifelong illness including liver cirrhosis and cancer.
- Spread: The hepatitis C virus is a bloodborne virus and most infections occur through exposure to blood from unsafe injection practices.
- Treatment: Direct-acting antiviral medicines (DAAs) can cure more than 95% of persons, there is currently no effective vaccine against hepatitis C.
- Hepatitis D: It only affects people who are already infected with hepatitis B, as it needs the hepatitis B virus to be able to survive in the body.
- It is usually spread through blood-to-blood contact or sexual contact.
- There’s no vaccine specifically for hepatitis D, but the hepatitis B vaccine can prevent it.
- Hepatitis E: It is generally a mild and short-term infection that does not require any treatment, but it can be serious with a weakened immune system.
- There’s no vaccine for hepatitis E.
Conclusion
- CRMA-1001 represents a new approach to treating viral infections by using epigenetic mechanisms to silence viral genes rather than directly attacking the virus.
- Although the findings are promising, further clinical trials are necessary to establish its effectiveness and long-term safety in humans.
Source: TH
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News In Brief 02-11-2026
