World's first mRNA flu vaccine approved: What it means for adults over 50

The US Food and Drug Administration has approved the world's first mRNA based seasonal influenza vaccine for adults aged 50 years and older. Experts say the technology could make future flu vaccines faster to produce and better matched to circulating virus strains.

In Short

• mFlusiva uses genetic instructions to trigger immunity without live influenza
• Adults aged 50 to 64 received full clearance from regulators
• People aged 65 and above got accelerated approval pending further studies

The messenger RNA, or mRNA, technology that became widely known during the COVID-19 pandemic is now entering a new chapter. In a landmark move, the US Food and Drug Administration has approved the world's first mRNA-based seasonal influenza vaccine, opening the door to a faster and more flexible way of protecting people against one of the world's most common viral infections.

The vaccine, called mFlusiva, has been developed by Moderna and is approved for adults aged 50 years and older in the United States. Scientists believe this new technology could transform how seasonal flu vaccines are made because influenza viruses constantly change from year to year. Unlike conventional vaccines that often take months to produce, mRNA vaccines can be designed and manufactured much more quickly, allowing health authorities to respond faster if new influenza strains emerge.

Although the approval currently applies only to the United States, experts say it represents a major milestone in vaccine science and could eventually influence how influenza vaccines are developed across the world, including in countries like India.

WHAT HAS THE US FDA APPROVED?

The US FDA has approved Moderna's mFlusiva for adults aged 50 years and above.

The approval includes:

• Full approval for adults aged 50 to 64 years.
• Accelerated approval for adults aged 65 years and older. Moderna must conduct additional studies to confirm long-term clinical benefits in this age group.

This is the first seasonal influenza vaccine to use mRNA technology instead of the traditional egg-based or cell-based manufacturing process.

WHAT IS AN mRNA FLU VACCINE?

Unlike conventional flu vaccines, which contain weakened or inactivated parts of the influenza virus, an mRNA vaccine works differently.

It delivers genetic instructions that tell the body's cells to temporarily produce a harmless influenza protein. The immune system recognises this protein as foreign and builds antibodies and immune cells that can fight the virus if the person is exposed later.

Importantly, the vaccine cannot cause influenza because it does not contain the live virus.

The same technology was successfully used in COVID-19 vaccines, helping scientists develop effective vaccines in record time.

WHY IS THIS TECHNOLOGY IMPORTANT?

Influenza viruses change constantly through mutations, which is why flu vaccines have to be updated every year.

Traditional flu vaccines are usually produced using eggs or specialised cell cultures. This manufacturing process takes several months, leaving little flexibility if the circulating virus changes after production has started.

Researchers believe mRNA technology offers several advantages:

• Faster vaccine development.
• Quicker manufacturing.
• Easier updates when new virus strains emerge.
• Better matching of vaccines to circulating influenza viruses.
• Potentially stronger protection for people at high risk of severe flu.

Experts say these benefits could improve future influenza vaccination programmes around the world.

WHAT DID THE CLINICAL TRIAL FIND?

The FDA's decision was based on a large Phase 3 clinical trial involving more than 40,000 adults aged 50 years and older.

According to Moderna, the study showed that the vaccine:

• Reduced laboratory-confirmed influenza cases by 26.6 per cent compared with a standard licensed flu vaccine.
• Produced stronger immune responses than Sanofi's high-dose influenza vaccine in older adults.

However, additional studies are still required to determine whether the stronger immune response translates into better real-world protection among adults aged 65 years and above.

Moderna is continuing post-approval studies across multiple influenza seasons.

WHY ARE OLDER ADULTS MORE VULNERABLE TO FLU?

Older adults are among the groups most likely to develop serious complications from seasonal influenza.

As people age, the immune system gradually becomes less effective at fighting infections. This increases the risk of:

• Pneumonia.
• Hospitalisation.
• Worsening of existing heart or lung diseases.
• Death from influenza-related complications.

According to the World Health Organisation, seasonal influenza causes an estimated 3 to 5 million cases of severe illness and up to 650,000 respiratory deaths worldwide every year.

This is why improving vaccine protection for older adults remains a major public health priority.

WHAT DOES THIS MEAN FOR INDIA?

The approval currently applies only to the United States.

India already has several licenced seasonal influenza vaccines that are recommended for people at higher risk of severe disease, including:

• Older adults.
• Pregnant women.
• Healthcare workers.
• People living with chronic medical conditions.

Whether mRNA-based influenza vaccines become available in India will depend on future regulatory approvals and decisions by Indian health authorities.

For now, India's influenza vaccination programme remains unchanged.

COULD THIS CHANGE THE FUTURE OF FLU VACCINES?

Scientists believe this approval is important not only because it introduces a new vaccine but because it demonstrates that mRNA technology can be used beyond COVID 19.

The success of mRNA vaccines has already encouraged research into vaccines against several infectious diseases and even certain cancers.

If future studies continue to show strong protection, mRNA-based flu vaccines could eventually become a key part of annual influenza vaccination programmes worldwide.

The approval of mFlusiva marks a significant step forward in vaccine science. It is the first time an mRNA-based vaccine has been approved for routine seasonal influenza prevention, offering the possibility of faster vaccine updates as flu viruses evolve.

While the vaccine is currently approved only for adults aged 50 years and older in the United States, the decision signals a new era in influenza prevention. As researchers continue to study its long term effectiveness, this breakthrough could shape the future of seasonal flu vaccination for millions of people across the world.

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