I would like to pitch in on that idea. In my opinion, I do not believe that even with “99.9% certainty” from computers will humans still find it necessary to use animals for testing. In addition, if we take a look back throughout the years, we can see the ethical changes we’ve made towards scientific experimentation that disagree with the idea that we want assurance at the cost of others. We’ve established laws that have limited and abolished certain testings on both human and animal subjects. Increase in consideration of the amount of harm a certain experiment may inflict on a subject, weighing the risks and benefits of a test, prioritizing the subjects’ health throughout an experiment, and completely illegalizing the use of many animals are only a few of the many changes we’ve made in the past to adhere to a higher standard of ethical scientific experimentation. Many of these decisions have been made not only because we strive to learn from past mistakes and cruelty, but also because the advancement in technology and techniques have allowed us to establish limitations while still improving healthcare. We can certainly assume that advancements in virtual simulations will play a key role in minimizing the use of animal testings and looking at our history, I would go as far to say that we will reach a point when virtual simulations will be faster and more accurate than animal testing when it comes to developing medical treatments and devices for humans and the use of any form of animal testings will be banned. At the very least, until we reach such a point, future technology will undoubtedly help develop medical solutions to give us enough certainty that animal and human testings will yield much less harm, discomfort, and deaths.

Sources:
Timeline of human trial laws: https://history.nih.gov/about/timelines_laws_human.html
Timeline of animal trial laws: https://history.nih.gov/about/timelines_laws_animal.html