The Centers for Disease Control and Prevention is expected to announce that people who are fully vaccinated against Covid-19 no longer need to wear masks or physically distance, indoors or outdoors in most circumstances, according to two sources familiar with the recommendations.The new recommendation comes more than a year after the CDC first recommended that Americans should wear masks to protect against spreading or catching the coronavirus. At that time, the U.S. was logging more than 1,000 Covid-19 deaths per day.Full coverage of the coronavirus outbreakA person is considered fully vaccinated two weeks after the last dose of Covid-19 vaccine. That gives the immune system enough time to develop antibodies against the virus. According to CDC data, more than 35 percent of the population has been fully vaccinated.There are a few caveats, however. People who have compromised immune systems, for example, should talk to their doctors about continuing with mitigation measures. And even fully vaccinated people may still be asked to wear masks in certain locations, such as in hospitals or other health care settings.Even though the vaccines work well, they are not perfect, and breakthrough infections can occur. Of the more than 117 million people in the U.S. who have been fully vaccinated, 9,245 later tested positive for Covid-19. Those illnesses have generally been mild.The CDC is expected to expand on the new guidance during a briefing Thursday afternoon.