The success of mRNA technology in case of COVID-19 vaccines has made pharmaceutical companies rush to use similar formulae for influenza vaccines. Pfizer, Moderna and Sanofi have all initiated phase-1 trials of mRNA-based seasonal flu vaccines and more pharma firms are expected to follow.

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However, getting approval for mRNA vaccines as flu shots will not be as easy as it was to get the go-ahead for COVID-19 vaccines. This is because, four distinct manufacturers already produce four distinct types of conventional vaccines in the United States.

What works for mRNA vaccines is that shots developed out of this technology may be able to afford immunity for a longer length of time. This is due to its high protein integrity and more precise strain selection. Additionally, mRNA technology also allows for the incorporation of a massive number of antigens which help improve immunity.

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On the other hand, as is evident with COVID vaccines, flu shots made from mRNA technology may face tolerance concerns due to side effects such as aching arms, headaches, low fever and lethargy. While these symptoms also occur in case of conventional flu shots, they are much milder in magnitude.

 But this apart, pharmaceutical firms say developing flu shots using mRNA tech has several benefits. The mRNA vaccines are synthetically made by encoding a target antigen sequence into a plasmid template. The shots need a high level of fidelity and encoded antigens must match the flu strains chosen for every year’s vaccination exactly.

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Conventional vaccines, on the other hand, use inactivated virus manufactured in egg and cell-based systems. These frequently suffer from sequence changes that lead to a lowering of efficiency.

Recombinant protein vaccines also have an identical fidelity benefit but manufacturing them takes much longer. The pliability and speed of mRNA vaccines is allowing pharma firms to compete to bring out mRNA vaccines for flu as soon as possible.