1An injection — administering medicine, a vaccine, etc., into the body with a syringe; the term can also refer to the shot or the needle itself.
インフルエンザの予防注射を受けた。
I got a flu shot.
看護師が腕に注射をしたとき、少し痛みを感じた。
When the nurse gave me the injection in my arm, I felt a slight pain.
治療には週に一度の注射が必要だと言われた。
I was told that the treatment requires a weekly injection.