The U.S. Centers for Disease Control and Prevention (CDC) recommended on Thursday that children aged 5 to 11 get a third dose of the Pfizer-BioNTech coronavirus vaccine to boost their immunity against COVID-19.

Since the pandemic began, more than 4.8 million children aged 5 through 11 have been diagnosed with COVID-19 in the United States, 15,000 have been hospitalized and over 180 have died, the CDC said in a statement.