Synthetic biologists have created a slow-growing version of the coronavirus to give as a vaccine

In the 1950s, Albert Sabin was searching for an improved polio vaccine. To that end, his lab infected the brains of mice, chimpanzees, and monkeys with the virus that causes the disease. They wanted to see if the pathogen would change and if weakened forms might arise. They eventually isolated versions of the polio virus that could still infect people but didn�t cause paralysis. Sabin�s so-called attenuated strains became the famous oral polio vaccine given on a sugar cube to billions of children.