100 million fully vaccinated people are helping the US reopen. But many millions more are needed

The United States has fully vaccinated more than 100 million people against Covid-19, according to the US Centers for Disease Control and Prevention — a milestone that comes with optimism about the future.The United States has fully vaccinated more than 100 million people against Covid-19, according to the US Centers for Disease Control and Prevention — a milestone that comes with optimism about the future.