A large-scale trial for an experimental flu shot from Moderna has fallen short of other, currently approved vaccines, said the company last week, but it has already made improvements to the formula and “hopes to confirm them in an upcoming clinical trial”.
Based on the same technology used in its successful Covid-19 vaccine, Moderna’s mRNA-1010 flu jab is “quadrivalent”, meaning it targets four strains of flu: A/H1N1, A/H3N2, B/Yamagata and B/Victoria – selected based on recommendations by the World Health Organisation (WHO).
The company said its flu shot generated an immune response against influenza A strains, that was equal or superior to that of already licensed vaccines, reports AFP.
However, it failed to measure up to already approved vaccines against strains of the less-common influenza B.
The phase three trial involved 6 102 adults in Argentina, Australia, Colombia, Panama and the Philippines during the southern hemisphere influenza season.
Participants received a single dose of mRNA-1010 or a single dose of a licensed influenza vaccine. Moderna said 70% of the mRNA-1010 recipients reported adverse reactions such as headaches, swelling and fatigue, compared with 48% the other group.
Virus strains have to be selected six to nine months before the vaccines are intended to be used, and their efficacy is approximately 40% to 60%.
Moderna is simultaneously conducting an efficacy trial of its vaccine.
The company and other vaccine manufacturers hope that mRNA technology – which provokes an immune response by delivering genetic molecules containing the code for key parts of a pathogen into human cells – can accelerate immunisation development and production, and heighten efficacy.
AFP article – Mixed results for Moderna mRNA flu vaccine trial (Open access)
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