An injection given to prevent disease — commonly refers to vaccination or immunization shots.
子どもは定期的に予防注射を受ける必要がある。
Children need to receive immunization shots regularly.
海外旅行前に予防注射を打っておくと安心だ。
It's wise to get preventive injections before traveling abroad.
病院で予防注射に関する説明を受け、同意書にサインした。
I received an explanation about the vaccination at the hospital and signed the consent form.