A federal advisory committee will decide Friday whether third shots of COVID-19 vaccines are safe and protective against infections. At root is whether the extra shots are "luxuries" or an essential part of providing complete protection against the virus, presidential adviser Dr. Anthony Fauci said this week. He and other federal officials, including President Joe Biden, believe it is time to begin offering third shots to compensate for what appears to be fading protection. The government has agreements to purchase the doses and provide them at no cost to consumers.