Lewis: Several companies are currently testing their vaccines in kids, as Scientific American contributor Melinda Wenner Moyer recently reported. Pfizer just announced results showing its vaccine is 100 percent effective in preventing COVID symptoms in 12- to 15-year-olds. Lewis: Companies wanted to make sure their vaccines were safe in adults first before testing them in kids. But COVID vaccines could be available to kids aged 12 to 16 this summer, for five- to 11-year-olds by early next year, and for babies and toddlers some time after that. Because people are still getting infected—rates are going up in several states—we still need COVID testing.