Prevention
Prevent
noun, verbal noun, の adjective
To prevent beforehand is still prevention.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
はしかの予防は、ワクチンしかありません。
The only prevention for measles is vaccination.
その国に行くなら、事前に必ずマラリア予防の薬を飲んでください。
If you go to that country, please make sure to take medicine to prevent malaria beforehand.
日焼けを予防するために、日焼け止めは欠かせません。
To prevent sunburn, sunscreen is essential.