The American Academy of Pediatrics reports that new child COVID infections are ballooning. There were 12,000 such cases during the first week of July; then 96,000 over the first week of August; and more than 121,000 COVID infections in kids between Aug. 5 and 12, or 18% of all cases reported that week. Hospitalizations in otherwise healthy children are also on the rise, and the disease may cause more serious symptoms in those who contract the variant, although pediatric doctors tell the Washington Post that the bulk of these young patients are either those under the age of 12, who don’t qualify for a vaccine yet, or eligible youth who have otherwise delayed getting a jab.

So which symptoms may be more prevalent among Americans with a Delta variant case, and specifically for younger people? Patient symptoms can vary widely, given the wide spectrum of COVID’s effects on the body among different patient demographics. Some relatively common signs of COVID include loss of taste and/or smell, fatigue, headaches, fever, trouble breathing, muscle aches and pains, gastrointestinal troubles like nausea, diarrhea, and vomiting, or a skin rash, among others. Projects such as the COVID Symptom Study allow patients to enter their own symptoms into a digital database that can track which ones are on the rise in which regions, as well as monitoring what new strains mean for those who contract “long COVID,” in which someone may be asymptomatic initially but then develop disease symptoms a month or more after infection.

Such studies and anecdotal evidence from major hospitals suggest that with the Delta variant, most symptoms occur in your head and nasal region. Gut problems and skin breakouts appear less prevalent in both adults and children with a Delta case. Many Delta cases also lack some classic symptoms of COVID.

“It seems like cough and loss of smell are less common. And headache, sore throat, runny nose, and fever are present based on the most recent surveys in the U.K., where more than 90% of the cases are due to the Delta strain,” according to Yale Medicine pediatric infectious diseases specialist and vaccinologist Dr. Inci Yildirim.

Others such as Dr. Michael Grosso, chief medical officer and chair of pediatrics at Northwell Health’s Huntington Hospital, largely concur based on their own patient experiences while noting subtle Delta symptom differences between kids and grownups. For instance, while cough may be less common generally among Delta variant patients compared with the original coronavirus, it may be more common among children, Grosso told Healthline, and while adults with the Delta variant may get a runny nose, a younger patient may not. In his experience, the most common symptoms in children who have the strain are fever and cough, “with nasal symptoms, gastrointestinal symptoms, and rash happening much less often.”

The number of COVID-related hospitalizations and deaths due to the Delta variant, while on the rise and a clear public health concern, still remain relatively low compared with the height of the pandemic, when upwards of 4,000 people were dying every day. That number is now closer to 450 to 750 new daily deaths, depending on which day’s data you’re looking at.

But the relative severity of Delta variant symptoms in younger people, especially the unvaccinated, has ICU doctors concerned since other COVID strains may have gone entirely unnoticed by an otherwise healthy patient with no underlying conditions. That may not be the case for this variety, raising fears of lasting damage in young adults and child patients who have to be hospitalized and recuperate from their illness.

The U.S. may still be in the earlier days of its COVID Delta reckoning, and only aggressive patient monitoring over the long term will help experts glean more knowledge about how different coronavirus mutations affect different people. But an extended battle with this persistent pathogen may further encourage federal officials to open up COVID vaccines to all ages and expand the reach of booster doses for the fully vaccinated sooner rather than later.

More health care and Big Pharma coverage from Fortune:

• U.S. COVID travel restrictions are slowing growth, new hires—and love
• Americans ineligible for COVID booster shots are already snagging extra doses
• Inside the FEMA program that spent $1 billion on COVID-19 funerals
• Hong Kong is stuck between being open to China and closed to the world, or open to the world and closed to China

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