Communicable Diseases More Condition_symptoms Is It Certain That There Will Always Be An Emergence Of New Communicable Diseases ?

Is it certain that there will always be an emergence of new communicable diseases ? - communicable diseases more condition_symptoms

If in the course of the centuries humans acquire immunity to these diseases, we can say we have found more resistance against infectious diseases that our ancestors? Is it somehow lost the immunity acquired in recent years has, or has survived in our genetic heritage? Finally, is worrying, there are new diseases to the idea that humanity has no immunity?