Given that there are several cancer vaccines currently in human trials, this is not surprising. Most are based in mRNA technology, like the COVID-19 vaccine. Basically, researchers identify the marker proteins of a specific cancer, then create an mRNA vaccine that sensitizes the immune system. Then the immune system attacks cells with that marker. Other advances are methods to take down the "shield" that cancer cells have that hides them from the immune system.

If a country chooses to ignore patents, they can copy the methods and produce their own vaccines with significantly less investment.