The Brief New guidance suggested by Dr. Vinay Prasad, in a paper published on Tuesday, argues for increased testing of seasonal COVID-19 shots. The FDA says the new approach will aim to balance a timely approval process for vaccines, while also weighing "the need for evidence" of their effectiveness. Dig deeper:Most Americans have come to expect annual updates to COVID-19 vaccines similar to the annual flu shot, as long as they show as much immune protection as the previous year’s version, officials have said. However, the new guidance could be the end of that approach, according to Prasad and FDA Commissioner Marty Makary – who co-authored the paper. According to estimates provided in the guidance, 100 million to 200 million Americans will still have access to vaccines in this manner.