小童病「百日咳」個案增加成為全球趨勢但係好多患病嘅小童都係未夠打防疫針嘅年齡所以更容易中招
By JosieLo (pupil) on 2011-08-30 Answers 1 Views 130
By wing cheng (graduate) on 2011-08-30
不過就算幼兒接種左疫苗,效用一般都維持唔到去青春期啦