evidence: Dr. Sara Oliver, a CDC scientist, stressed at Thursday's advisory meeting that because the federal government has purchased all of the COVID-19 vaccines on an emergency basis for the pandemic, including the Pfizer vaccine, vaccine providers are required to follow the recommendations of the CDC and the FDA. [...] U.S. regulators will rule on booster guidance for those who have gotten the Moderna or Johnson & Johnson vaccine at a later date, The Associated Press reported. Moderna's two-shot vaccine and Johnson & Johnson's one-shot vaccine are currently offered under an emergency use authorization, pending formal FDA approval. Like the FDA, the CDC panel's decision breaks with the Biden administration's sweeping booster strategy to offer an extra dose to most age groups as early as this week in an effort to protect Americans against the highly contagious delta variant.