Imagine if the same strategy were applied to biological warfare. Novel viruses tailored to be symptomatic and cause harm to just one specific world leader. If the technology exists, it could be the most formidable assassination tool available; a self-delivering, non-nuclear ace-in-the-hole for winning a war.
This concept is featured in The Dark Forest, the second book in the Three Body Problem trilogy. It was something where you could genetically tag someone and then if they woke up 50 years later from a chrono sleep, various systems were preprogrammed to have "accidents" around them, like self driving cars, etc.
I was about to comment “hey, spoiler alert”, but then I realised that you’re talking about a game released a quarter of a century ago. More time has passed since MGS came out than passed between the Ramones’ first gig and MGS’s release. Mad.
Unlikely this could ever be done. We share too much of the same firmware for something like to be possible. The average human genome has about 4-5 M single nucleotide polymorphisms (SNPs) - rate in the order of 1 SNP / 1000 bases. The rate is much lower in functionally important parts of the genome because those tend to be under evolutionary constraint / conservation.
It's probably not that imaginary. There was much hand ringing during COVID that Russia's testing protocol for meeting Putin would allow them to collect DNA from world leaders.
And conversely, the article also mentions Putin’s social distancing, which could be a rational defensive measure against biological warfare that he believes might exist, rumors of an undisclosed serious health issue notwithstanding.