Hepatitis Bvaccine的用法和样例：
例句
- Cost is the main reason why mass vaccination against hepatitis B is not offered, he believes.
他相信成本问题是没有实行大规模乙肝疫苗接种的主要原因。 - Hepatitis B vaccine is recommended for all babies so that they will be protected from a serious but preventable disease.
让所有的婴孩都接种乙肝疫苗，是为了防止他们感染某种严重的却是可预防的疾病。
