加强针
Booster shot
 

10月23日，在北京市大兴区亦庄镇一处接种点，医务人员为市民接种。新华社记者 彭子洋 摄

据《北京日报》报道，10月起，越来越多的城市开始提供新冠疫苗加强针，以增强应对病毒的免疫力。国家卫健委表示，加强免疫接种目前优先在感染高风险人群和保障社会基本运行的关键岗位人员中开展，全程接种满6个月的18岁及以上人群，可进行一剂次加强免疫。

Starting in October, an increasing number of cities in China began offering COVID-19 booster shots to strengthen  people’s immunity to the virus, Beijing Daily reported. According to the National Health Commission, the focus at present is to give booster doses to people at higher risk of contracting the virus and key workers in the public sector. The third vaccine dose will also be made available to people aged over 18 who have already had the two-shot vaccination for at least six months.

疫苗加强针 (booster shot/dose/jab)，指在完成疫苗接种后根据抗体消退的情况进行补充接种，保持人体对病毒免疫力的疫苗剂次。Booster动词形式为boost，表示“加强”，这里指“增强疫苗产生的效果”。