The primary benefit of the yellow fever vaccine is that it provides effective protection against yellow fever, a potentially fatal viral disease transmitted by mosquitoes.

Many countries require proof of yellow fever vaccination for entry, particularly if you are coming from or have recently visited a yellow fever-endemic area. 

Vaccination helps prevent the spread of yellow fever within and between countries, particularly in areas where outbreaks are more likely to occur. 

For travelers visiting yellow fever-endemic areas, the vaccine significantly lowers the risk of contracting the disease, which can lead to serious health complications or death.