How Vaccines Work

A health infographic explaining how a vaccine trains the immune system, drawn as a four-panel numbered sequence. Panels show the injection of a harmless antigen, immune cells detecting it, antibody production, and memory cells ready for the real pathogen. Simple friendly cell characters with icons, arrows linking the panels. Clean flat medical style, a calming teal, coral and white palette on light grey. Bold title 'How Vaccines Work' upper-left, a small shield motif and a one-line takeaway caption at the base.

一张健康信息图,讲解疫苗如何训练免疫系统,画成四格编号序列。四格分别展示注射无害的抗原、免疫细胞识别它、产生抗体,以及记忆细胞随时应对真正的病原体。简单友好的细胞角色配图标,箭头串联各格。干净的扁平医学风格,舒缓的青色、珊瑚色与白配色,浅灰底。左上角粗体标题「疫苗的工作原理」,底部一个小盾牌图案与一句要点说明。