When we get sick, our body does not wait for the pathogens to invade our tissues and systems. Instead our body fights with its immune system. When germs such as COVID-19 invade our body, our immune system attacks and multiplies. When a germ such as COVID-19 enters our body, our immune system may need several days or weeks to be sufficiently fighting against it. Even though we have learned with other germs that the immune system usually produces memory T cells which help develop immunity faster, the mechanism after a COVID-19 illness is still not clear. To help you gain better insight about acquired immunity, here is a video that compares COVID-19’s immunity with six other diseases: