Dan Brown earns money by making sacrileges and blasphemies. First he earned money on Christianity, when he wrote "The Da Vinci code", a book in which professor Langdon discovers a conspiracy that tries to hide the fact that Jesus Christ had a child with Mary Magdalene.
In book "Angels and demons" a new conspiracy within Catholic Church brings a lot of cash for Dan Brown.
In "Inferno" the sacrilege is more secular: the desire of a elite to play the god.
The Italian cathedrals are used only as scenery, while professor Langdon is trying to foil a plot in which a billionaire is trying to trim the human population by 50%.
The director Ron Howard, has made the characters more deep, the "villains" are some smart people that want to save the world using an inhuman solution.The images of Langdon having hallucinations regarding the inferno are very creative and disgusting.
But as in other Dan Brown's book there are holes in the story.
If in the "Angels and demons" it was the antimatter. (It is very expensive and it is very hard to transport), in "Inferno" the biggest hole is the production of a deadly virus.
In order to produce a virus you need a lab, with specialists in microbiology and they will know what you try to do, and they will try to stop you and disclose the informations or they will try to protect their families by giving them a vaccine, which will rise questions.
Also the virus must be tested, on humans, this will increase the mortality rate of some population, and draw attention of medical authorities.
Zobrist the bad guy from "Inferno" would have a hard time to produce a virus without raising suspicions.
It would be simpler for him to buy some TV stations,news papers and some websites and promote via these media outlets that the vaccines are bad.
The simpletons would believe this they will not take their vaccine shots, and some different epidemics would wipe them.
And the beauty of the plan is that he and his family would be alive because they are protected by common vaccines, and even if the plot would be discovered, he could be accused only of misinformation.