Here in the United States, more than 4 million coronavirus vaccine shots were administered for the first time in a 24-hour period Saturday. The seven-day average for vaccines is now higher than 3 million a day as more states continue to expand eligibility to anyone 16 or older. Nearly a third of people in the U.S. have received at least one dose of a vaccine, with close to 20% fully vaccinated. Despite the increasing pace of vaccinations, health experts continue to sound the alarm for a possible fourth wave. This is Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention.

Dr. Rochelle Walensky: “It is important that everyone, regardless of vaccination status, continue to take prevention measures in public and adhere to our guidance on ways to reduce the spread of COVID-19: Wear a mask, physically distance, avoid crowds and poorly ventilated areas, and wash your hands frequently.”

The CDC said Friday fully vaccinated people can safely travel both domestically and internationally, though the agency still recommends against nonessential trips due to the high number of infections.