‘Tripledemia’ data shows cold and flu season already among worst on record

After two difficult Covid winters, the current respiratory disease season already rivals some of the worst cold and flu seasons on record, starting about two months earlier.

RSV, or respiratory syncytial virus, has done so many sick little kids this fall that weekly pediatric RSV hospitalizations are the highest on record. The flu, which normally peaks in February, has pushed hospitalization rates to the highest level for this time of year in more than a decade, surpassing hospitalizations for covid-19. And while covid disease is lower than it has been in the last two Decembers, it’s also rising.

Public health officials have been warning for weeks that a “tripledemia” of Covid-19, the flu and RSV would test an already tired health care system. Hospitalizations for all three viruses have risen together. Nationally, RSV appears to have peaked and influenza is peaking in some parts of the country, but infections from the two viruses are expected to stabilize at high levels.

Experts say it’s hard to estimate the severity of the remainder of this season because the coronavirus pandemic disrupted somewhat predictable patterns for other respiratory illnesses.

“There’s a lot of winter left,” said Richard Webby, a virologist at St. Jude Children’s Research Hospital in Memphis. “Certainly there is plenty of time for another wave of covid, and potentially even enough time for another version of the flu.”

The country has already faced two record-breaking seasons under covid, which has disproportionately affected older Americans, but the return of RSV and flu this year means that part of the disease burden has shifted to the youngest of the country and their families.

Weekly RSV hospitalizations among children are the highest since the Centers for Disease Control and Prevention began its surveillance in the 2018-19 season. About one in 70 babies 6 months or younger have been hospitalized since early October, according to preliminary estimates.

With the increase in the flu and the circulation of Covid-19, respiratory diseases have overwhelmed pediatric units across the country, shifting the stress to emergency rooms and children’s hospitals.

“Ask people who are involved with emergency services or hospitalizations and they will tell you this is the worst season they can remember,” said Dr. Daniel Rauch, chief of pediatric medicine at Tufts Medical Center.

“We are quite scared for the winter,” he added. “I don’t know if our staff can continue like this.”

RSV cases and hospitalizations appear to be peaking, particularly in the South where the disease arrived first, but some experts predict they will level off and remain high for some time.

RSV hospitalizations for older adults are also much higher than those recorded at this time of year in past seasons.

Older Americans remain extremely vulnerable to serious illness from Covid-19 and the flu, and with the flu’s early return and dramatic rise, public health officials are concerned about this age group.

“Covid hasn’t gone away,” said Dr. Fiona Havers, an infectious disease specialist at the CDC. “Hospitalizations, particularly in older adults and people with high-risk conditions, are still occurring at high rates.”

Influenza hospitalizations among the elderly are expected to increase in the coming weeks as families continue to travel and gather indoors for the holidays. The predominant type of flu circulating right now, a subtype of flu to known as H3, also tends to lead to higher numbers of flu hospitalizations among the elderly, according to the CDC

The agency estimates there have been at least 150,000 hospitalizations and 9,300 deaths from the flu alone so far this season. It has also reported 30 flu deaths among children, a fraction of the estimated 199 pediatric flu deaths in the 2019-20 season.

Experts say the available flu and covid-19 vaccines are good matches for the circulating strains. That means the shots should offer some protection against infection, although they are more effective at protecting against serious disease. For those who have already had the flu, the vaccine can protect them against another strain to which they have not been exposed.

But vaccination rates are low across the country. Single 36 percent of people 65 years or older they have received an updated Covid-19 booster this fall, and rates are lower for all of the younger age groups. About 15 percent of adults 65 and older and about 46 percent of children have received the flu vaccine.