What is immunity?

Immunity refers to the ability of the human body to resist foreign invasion such as viruses, bacteria and fungi. The human immune system consists of many kinds of cells and molecules, including white blood cells, antibodies and lymphocytes. When foreign pathogens invade the human body, the immune system will immediately start the reaction and identify, locate and eliminate the pathogens through various mechanisms.

The level of immunity is closely related to human health. When immunity is strong, the human body has strong resistance to diseases, and the probability of getting sick is relatively low; On the contrary, when the immunity is weak, the human body is easily infected with various diseases.

The improvement of immunity can be achieved through many ways, including good living habits, balanced diet, proper exercise and adequate sleep. In addition, vaccination is also one of the effective ways to improve immunity. Vaccine can produce antibodies in human body and improve human immunity to diseases.

In a word, immunity is one of the keys to maintain human health, and we should pay attention to the improvement and maintenance of immunity.