The United States is experiencing another surge in COVID-19 cases as the summer comes to an end.  

COVID-19 infections are increasing in 27 states, according to the Centers for Disease Control and Prevention (CDC).

Traces of the disease are becoming more common in wastewater, with the CDC’s wastewater surveillance system now reporting “very high” levels of COVID-19.   

On Aug. 17, the CDC reported a wastewater viral activity level for COVID-19 of 8.86 marking a significant jump from early May when the level was 1.35, or a “minimal” level. The agency reported a recent national peak of 9.56 in July.  

Some doctors suggested the recent surge in COVID-19 infections could be one the largest summer waves the nation has experienced since the COVID-19 pandemic began. 

CDC data shows that emergency room visits, hospitalizations and COVID-19-related deaths have been on the rise since May.

Hospitalization rates, for example, for the week ending on Aug. 10 reached a rate of 4.6 per 100,000, more than four times the rate in early May.  

The rate of COVID-19 hospitalizations has since dropped, falling last week to 3.1 per 100,000 people, according to the CDC.  

The KP.3.1.1 strain, the most dominant strain of the virus, accounted for 36.8 percent of all cases from Aug. 8-17, while the KP.3 strain made up about 17 percent of cases, according to the most recent CDC data available.

The summer variants have similar symptoms to the earlier Omicron variants like fever, chills, runny nose, stuffiness and cough.  

While the summer variants aren’t more deadly, they “are almost certainly more contagious,” Otto Yang, associate chief of infectious diseases at UCLA told NPR.

“So, if you have something that’s equally deadly but more contagious, you will see more severe illnesses and deaths,” he said. 

The Food and Drug Administration last week approved updated COVID-19 vaccines from Moderna and Pfizer. When announcing the approval, the agency cited the recent rise in cases as part of their decision. 

On Friday, the agency also approved another updated SARS-CoV-2 vaccine from Novavax.