Confirmed Covid-19 cases among children in the US have reached record levels since the 2020 winter surge, according to the latest report from the American Academy of Pediatrics and the Children’s Hospital Association.

As of August 19, over 4.59 million children have tested positive for the virus since the onset of the pandemic early last year, Xinhua news agency quoted the report issued on Wednesday as saying. More than 180,000 cases were added the past week, reaching levels of the previous winter surge, the report said.

After declining in early summer, child cases have increased exponentially, with over a four-fold increase the previous month, rising from about 38,000 cases the week ending July 22 to 180,000 the past week.

According to the report, at this time, it appears that severe illness due to Covid-19 is uncommon among children.

However, there is an urgent need to collect more data on the longer-term impacts of the pandemic on children, including ways the virus may harm the long-term physical health of infected kids, as well as its emotional and mental health effects, it added.

The rise has come as 48.4% of the population is yet to be fully vaccinated, according to data from the US Centers for Disease Control and Prevention (CDC), and as the average of daily new reported cases rises to more than 151,000.

Health experts have been particularly concerned about cases among children as students return to school, many without mask mandates and without access to vaccines.

Pfizer/BioNTech’s vaccine was fully approved by the US Food and Drug Administration (FDA) Monday for Americans 16 and older, which National Institutes of Health Director Dr. Francis Collins told CNN was a “ray of sunshine in the midst of all these dark COVID clouds.”

Similarly, Moderna announced on Wednesday it has completed its submission to the FDA for full approval of its COVID-19 vaccine for people age 18 and older. Moderna said it has requested a priority review from the agency. Moderna’s vaccine is currently available under emergency use authorization for people age 18 and older. The company began submitting data for approval to the FDA in June.