流行性感冒的疫苗因為屬於自費型，要形成 #群體免 [https://www.facebook.com/hashtag/%E7%BE%A4%E9%AB%94%E5%85%8D%E7%96%AB?epa=HASHTAG] 疫 [https://www.facebook.com/hashtag/%E7%BE%A4%E9%AB%94%E5%85%8D%E7%96%AB?epa=HASHTAG] #HerdImmunity [https://www.facebook.com/hashtag/herdimmunity?epa=