Who knew that bacteria are attacked by viruses and have developed sophisticated defence mechanisms which chop up the viral DNA and then store snippets which help them recognise the same invader in the future?

Walter Isaacson, a former editor of Time magazine, unveils the process of this critical discovery and its implications in a very readable and compelling narrative. There are twists and turns, fierce competition, rivalry and the excitement of discovery. It is as readable and yet better than any work of fiction.

Jennifer Doudna’s interest in bio-chemistry is kindled when as a 12 year old her father gives her The Double Helix, the story of unpacking the structure of DNA. This ignites a passion to understand how nature works and eventually with collaborator Emmanuelle Charpentier in 2012 she finds herself at the place where unexplained repeated segments in bacterial DNA lead to the possibility to harness that bacterial defence mechanism. Designated CRISPR it turns out to be an easy-to-use tool to edit DNA. Doudna and Charpentier would be awarded the Nobel Prize for Chemistry in 2020 for this discovery.

While Jennifer Doudna is central to the unfolding discoveries, she is by no means the only contributor. Isaacson gives significant space to the very many scientists working in the field. At times credit for a discovery or advance is a matter of days as to who gets published first, or if an additional payment was made for priority peer review. In fact every discovery or improved process is reliant on the success and sometimes the failure of others.

CRISPR launched the world into a life science revolution where it will become common place to study and possibly alter the code of life. Genetic diseases such as Huntington’s and Sickle Cell Anemia both due to a single, easily corrected, DNA error could be eliminated. But it could also be possible to select for eye colour, add extra strength or height.

The chapters on the ethics of gene editing are comprehensive and could be considered on their own without reading the whole book. A common concern is that these discoveries will increase the gap between those who can and cannot afford such treatment. Doudna has the view such gene editing should only be used when ‘medically necessary’. She feels that ‘enhancements’ for children are morally and socially wrong but acknowledges that this line can be blurry. These are the questions that need careful consideration.

The final chapters show how rivalries are put aside between competing scientific teams to work on a vaccine for the new and dangerous virus Covid-19. A key puzzle: how to get the active component of the vaccine into the human cell where it can help prime the immune system. Two vaccine makers, Pfizer and Moderna, use the CRISPR technology.

Gene editing can be seen as a source of hope for the future in rolling back disease or could it be something which endangers and threatens the future of humankind? Isaacson ends with a plea for scientists and humanists to ask the question “What type of world do we want to leave for our children?” and then to feel their way forward preferably hand in hand.

NB: My copy of this book came from the public library.