But more studies are needed to confirm splashback isn't a concern, Weniger says. He also worries that gas-based vaccines might leave scars. That was a problem with older gas-based systems. Some visible metallic residue remained in the skin.

但韦尼格说，还需要更多的研究来证实溅回不是一个问题。他还担心基于气体的疫苗可能会留下疤痕。这是旧式气体系统的一个问题。一些可见的金属残留物残留在皮肤上。