As the U.S. enters the holiday season, there is fear that the flu situation could get more alarming in the coming weeks.

Based on the latest data from the Health and Human Services Department, flu hospitalizations have increased by nearly 30% in a week. More than 11,200 people were hospitalized due to the flu virus in the week ending Nov. 19, CNBC reported Monday.

Compared to the previous week which recorded about 8,700 hospitalizations, there’s been a big jump in cases, leading experts to believe that the spread of the respiratory illness has remained high across the country.

Flu season started earlier than usual this year, taking a toll on the emergency departments and hospitals amid the ongoing COVID-19 pandemic. In the past, flu activity typically picked up after Thanksgiving. But hospitalizations were already significantly high in early November this time around.

“The fact that we’re already at this high level going into the holiday season makes me nervous,” microbiologist and flu expert at the Penn Institute for Immunology Scott Hensley told the outlet.

As early as October, flu activity in the country already set a record. About 11 people out of 100,000 have been hospitalized, the highest level recorded in a decade.

According to the Centers for Disease Control and Prevention (CDC), around 35 states have been experiencing high or very high flu activity. Only 6 states were reporting low activity, and most were in the north.

This flu season alone, more than 6.2 million people have fallen ill due to the influenza viruses, around 53,000 have been hospitalized, and 2,900 have reportedly died.

As flu activity continues to climb higher, public health experts worry that more pediatric deaths could be reported in the coming weeks. Just recently, five more pediatric cases reportedly died, bringing the season’s total to 12, said the Center for Infectious Disease Research and Policy.

The pediatric deaths reportedly occurred between early October and mid-November. All of the cases involved influenza A. H1Na and H3N2 were the two subtypes reported among the pediatric deaths.

Though vaccine efficacy data has not been published yet, experts said they worked well with the newer strains. Hence, they encouraged everyone to get vaccinated to stay protected for the remainder of the flu season.

“From what we can see, it looks like the vaccines are pretty darn good matches to what’s circulating. If there’s ever a time to get vaccinated, this is the year to do it,” Hensley said.