Covid-19 vaccines will be closely monitored by the U.S. Centers for Disease Control and Prevention through daily text messages and emails, according to a federal advisory group.Essential workers who are expected to be the first recipients will get daily text messages on their smartphones asking about side effects in the first week after they get the shot, and then they’ll be contacted weekly for six weeks, said Tom Shimabukuro, a CDC immunization expert, at a meeting of the CDC’s Advisory Committee on Immunization Practices.