Prelims: Current events of national and international importance | Science & Technology
Why in News?
Recently, the U.S. Food and Drug Administration (FDA) refused to review Moderna’s new mRNA influenza vaccine (mRNA-1010).
mRNA – They are messenger RNA that acts as a blueprint for creating proteins essential for body functions.
mRNA copies instructions from Deoxyribonucleic acid (DNA) and serves as a template for cells to produce specific proteins.
Temporary Role - Cells use mRNA to produce the protein and then degrade it once the job is done.
Limitation – Errors in DNA can affect mRNA instructions, potentially causing diseases.
mRNA Vaccines –These vaccines use a copy of mRNA to produce an immune response.
It encodes a viral protein, usually the spike protein, without exposing individuals to the virus itself.
Mechanism –The mRNA is delivered into immune cells, which produce the protein, triggering an adaptive immune response.
It teaches the body to recognise and destroy the virus.
Features – Easy and fast to design with lower production cost.
Can be updated quickly for emerging viral strains.
Induce both cellular (T Cells) and humoral (B Cells) immunity.
Does not alter genomic DNA.
Challenges – Require ultra-cold storage (-90°C to -50°C).
May cause adverse reactions in individuals prone to autoimmune responses.
Long-term effects are still unknown.
Difference from Traditional Vaccines – Rapid development – mRNA vaccines can be designed in days to weeks once the viral genetic code is known, unlike traditional vaccines that may take years.
Traditional Vaccines – Introduce viral proteins or a weakened/inactivated virus into the body.
Stimulate the immune system to recognize and fight the real virus.
Viral Vector Vaccines – Use a harmless virus to deliver DNA coding for a viral protein.
The body’s cells produce the viral protein, which triggers immunity.
mRNA Vaccines – Deliver mRNA instructions wrapped in lipid molecules for stability.
Cells use the mRNA to produce the viral protein themselves, stimulating an adaptive immune response.
FDA’s Refusal
mRNA-1010 – It is an mRNA-based seasonal influenza vaccine targeting seasonal influenza A and B strains.
Core Issue – Moderna compared the mRNA-1010 vaccine to a standard-dose flu shot.
FDA stance – Adults who are 65 and above require high-dose or adjuvanted vaccines as the preferred standard.
Using a weaker comparator made the trial “inadequate and not well-controlled” for review.
Future Implications – Delayed Access –While mRNA-1010 has been accepted for review in the EU, Canada, and Australia, its availability in the U.S. is now delayed indefinitely.
Combo Vaccine Impact – This refusal also stalls Moderna's combination flu/COVID-19 vaccine (mRNA-1083).
Industry Precedent – FDA sets a higher bar requiring the strongest available comparator for future vaccines.
