The Andromeda Strain: Day 5, Chapter 30 & Epilogue

Day 5: Resolution
30. The Last Day
About fifteen minutes later, Hall is in the infirmary recovering from his ordeal. On a television monitor, Stone tells him that the organism is now over Los Angeles and is having no effect on anything. Later, Stone says it has mutated into a benign form, but had the bomb gone off at the lab it would have been another story. He says that he believes the organism will move into the upper atmosphere and cause no further damage on earth.
The official explanations of the various incidents cover up what really happened. NASA decides to suspend manned spaceflights indefinitely.
Some readers experience a sense of let-down in this anti-climactic ending. The scientists have finally figured out how the virus operates (they think) and Hall has saved the facility from self-destructing, but then they discover that the bacteria has mutated into a harmless form, which would have happened had they spent the last few days just sitting around solving crossword puzzles. The climax Crichton inserted, as Hall struggles to reach the substation to turn his key and prevent the atomic bomb going off, lacks tension, since at many points in the book it has been made clear that everyone survives the crisis. Another objection that has been brought to the ending is that viruses do not go through only one mutation. Because one type of mutation has occurred, it does not mean that all the viruses will mutate in the same way. It therefore seems odd that the scientists think the problem has been solved. Crichton also leaves a loose end in the plot, in the human bone clean of flesh that is discovered after the plane crash in Utah. None of the other victims had their entire flesh destroyed, leaving only clean bone. Presumably this is the effect of the first mutation Andromeda goes through, but if that is the case, why, when the rubber gaskets at the Wildfire Laboratory dissolve, does human flesh not dissolve as well? Stone explains that the virus is now harmless to man but destroys rubber gaskets, in which case it must have mutated once again from what it was when it destroyed plane and pilot over Utah. But this is never pointed out and seems like an oversight on the part of the author.