LANSING, Mich. (WLNS) – There have been warnings all winter about a so-called “tripledemic” of COVID, RSV, and influenza, and new research suggests it is young children who have been impacted the most.

A study in the Journal of Pediatrics looked at children who were hospitalized with COVID.

Those under age five who tested positive for a second virus, such as a cold, were significantly more likely to receive increased oxygen support or be admitted to the intensive care unit.

Research from the Centers for Disease Control and Prevention found that children under age two who also had RSV were twice as likely to have severe respiratory illness, compared to those without RSV.

“Young children haven’t had the experience of these viruses that we older folks have had,” said William Schaffner, a Professor at the Vanderbilt University Department of Medicine.

“It stands to reason that they may get hit a little harder and get a little sicker,” Schaffner said.

Among the entire U.S. population, the CDC says influenza and RSV cases have started to decline in most areas, but COVID cases are on the rise compared to the autumn season.

“The winter is not over; those viruses are still out there. Let’s continue to take good precautions,” said Schaffner.

Health experts say those precautions include making sure young children are vaccinated against COVID and the flu.