Today a subunit hepatitis B vaccine is made by genetic engineering.Scientists use the gene for a specific hepatitis B protein to manufacture pure copies of the protein.

• 目前，B型肝炎的次单位疫苗则是利用遗传工程技术所制造，科学家利用某个特定B型肝炎蛋白的基因，制造出许多该蛋白的复本。