Title is misleading. It's not a vaccine. They genetically engineer the parasite to reduce its lifetime so that it does not persist in the liver. It's not a long-term solution because the parasite can potentially evolve and overcome the modifications that reduce its lifetime. Moreover, the immunity boost is unlikely to last forever so they'll have to figure out a booster strategy as well.
Title is misleading. It's not a vaccine. They genetically engineer the parasite to reduce its lifetime so that it does not persist in the liver. It's not a long-term solution because the parasite can potentially evolve and overcome the modifications that reduce its lifetime. Moreover, the immunity boost is unlikely to last forever so they'll have to figure out a booster strategy as well.