The reason mRNA vaccines don't work as well on your grandparents isn't that their immune system is weak—the vaccine just has a hard time physically getting where it needs to go.
April 13, 2026
Original Paper
Engineering age-adaptive mRNA lipid nanoparticle cancer vaccines via reprogramming systemic gene expression
bioRxiv · 10.64898/2026.04.11.717910
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The Takeaway
Researchers found that older bodies struggle to translate the vaccine's instructions into proteins, not to fight the virus itself. By simply changing the "packaging" of the vaccine, they can make it work just as well as it does in young people.
From the abstract
Lipid nanoparticle (LNP)-based mRNA vaccines have transformed cancer immunotherapy, yet their efficacy in older individuals, who represent the majority of cancer patients, remains poorly understood. Here, we uncover a critical and previously underappreciated barrier to mRNA LNP cancer vaccine performance in aged hosts: impaired systemic transgene expression. Using the SM-102 mRNA LNPs as a benchmark formulation, we show that while local immune activation and antigen presentation at the injection