The first edition of the monumental book by Sir Fred Hoyle and N Chandra Wickramasinghe appeared some 40 years ago, encapsulating the key principles of Panspermia, and it has been the guiding principle in the new scientific field of Astrobiology.This latest edition continues to describe the consequences of the theory of cometary panspermia that relate to the origins of epidemic disease. Available data on historic and modern plagues are analysed to show that extraterrestrial bacteria and viruses are the cause of ongoing pandemics of diseases.Adherence to an inappropriate and obsolete theory of pandemics could put in jeopardy the economic well-being of the entire world, perhaps even threatening the continued existence of our civilization.