How long after a dog bite is it effective to get a shot?

In general, it is better to receive the rabies vaccine as soon as possible after a dog bite, and vaccination within 24–48 hours is usually effective.

After entering the body through a wound, the rabies virus gradually travels toward the central nervous system along nerve tissues. Before the virus extensively replicates and attacks the central nervous system, vaccination can stimulate the body to produce sufficient antibodies to effectively neutralize the virus and prevent the onset of disease. Receiving the vaccine within 24 hours after the bite significantly reduces the risk of developing rabies, as the body's immune system can respond quickly and mount a defense against the virus.

However, even if more than 24 hours have passed, vaccination still holds value. As long as the complete vaccination series is administered before the onset of rabies symptoms, it may still provide protection. Even if the virus has begun spreading within the body, the immune response triggered by the vaccine may still be able to control the virus before it attacks the nervous system. Nevertheless, as time progresses, the virus may spread further within the body, increasing the risk of disease. Therefore, once bitten by a dog, one should seek medical attention promptly for wound assessment and vaccination scheduling, rather than delaying with the hope of侥幸 (侥幸 means侥幸 in Chinese, implying wishful thinking or hoping for luck).