A revolutionary new vaccine in the battle against influenza – Cosmos

ByVinod RMT Balasubramaniam,

Monash Universityin Kuala Lumpur

Clinical trials of a universal influenza mRNA vaccine have begun in the US.

The US National Institute of Allergy and Infectious Diseases has started enrolling volunteers at Duke University in North Carolina to test itsexperimental mRNA-LNP vaccineagainst seasonal influenza, one of several universal influenza vaccine candidates now in the pipeline.Another clinical trialhas begun at the US National Institutes of Healths Clinical Centre in Maryland.

Influenza kills up to 650,000 people around the world each year.

Ninety-nine percent of deaths in childrenunder five years of age in developing countries are due to influenza-related infections, according to the World Health Organization.

The current crop of influenza vaccines haslimitationsin effectively combating thebillion casesof seasonal influenza each year as they provide immunity against only one specific existing strain or mutation. The propensity of flu viruses to mutate into new strains means vaccines must be continuously monitored and reformulated each year.

But a universal influenza vaccine, using mRNA technology which was used with success during the COVID pandemic has the potential to provide broader and longer-lasting immunity against diverse influenza strains.

The technology allows for rapid development and deployment and offers versatility in targeting multiple regions of the influenza virus.

New or mutated influenza variants are always a threat, particularly those originating from animal sources. Pandemics such as theSpanish fluof 1918, which killed 50 million people, and recent outbreaks of theavian influenza(bird flu) viruses underscore the persistent threat posed by influenza.

It also underscores the urgent need for auniversal influenza vaccinecapable of safeguarding against all subtypes of the virus.

In recent years, lipid nanoparticle (LNP)-encapsulated nucleoside-modified mRNA (mRNA-LNP) vaccines have emerged as a potent tool in combating influenza and other infectious diseases.

These vaccines use mRNA created in a laboratory to teach our cells how to make a protein or even just a piece of a protein that triggers an immune response inside our bodies.

The limited efficacy of current vaccines can be attributed to their focus on only generating strain-specific antibodies against the influenza virus hemagglutinin (HA). This is a protein within the virus which causes infection.

To broaden protective immunity, novel vaccine strategies aim to elicit responses against more proteins (fragments of a virus). One promising avenue involves triggering T-cell responses. T-cells are a type of white blood cell and are part of the bodys immune system.

T-cell-mediated immunity not only eliminates infected cells but also correlates with improved outcomes in individuals affected by influenza.Animal studieshave demonstrated the protective role of T-cells against various influenza virus strains.

These vaccines, exemplified by the successful development and global deployment of mRNA-LNP-basedCOVID-19 vaccines, elicit robust T-cell and antibody responses. These vaccines also offer the advantage of rapid production and adaptation to target emerging viral variants.

While several mRNA-LNP influenza vaccines arein development, most prioritise stimulating antibody responses and under-exploit the potential of T-cell immunity.

As shown by COVID-19, mRNA vaccines have demonstrated safety and efficacy in clinical trials forvarious infectious diseases. This instils confidence in the feasibility of developing a universal influenza mRNA vaccine that is safe and effective.

Ongoing advances in mRNA technology, such as improveddelivery systems and stabilisationmethods, further enhance the prospects of creating a universal influenza vaccine that ticks all the boxes.

The mRNA vaccine technology offers several advantages, including rapid development, scalability, and precise design. Two categories of mRNA vaccines exist,conventional and self-amplifyingand both are being explored for their potential to confer broad protection against influenza viruses.

Despite their promise, challenges remain in effectivelydelivering mRNA moleculesinto a vaccine due to their inherent instability. Overcoming these challenges is essential for the successful development of universal mRNA vaccines for influenza.

Dr Vinod Balasubramaniamis Associate Professor (Molecular Virology) at the Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia.

Originally published underCreative Commonsby360info.

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A revolutionary new vaccine in the battle against influenza - Cosmos