'Tripledemic' underscores vaccine need

COVID-19 among viruses straining US hospitals as broader flu jab tested

As US hospitals battle a "tripledemic" of rising numbers of viral infections, scientists are testing a vaccine that may protect against 20 strains of influenza.

Across the United States, medical workers are being stretched by increasing cases of the flu, respiratory syncytial virus, or RSV, and COVID-19.

The vaccine, which is in its early stages of development, wouldn't replace annual flu shots but would provide a shield against severe disease and death from potential pandemic threats. And many see the work of the scientists as helping to prevent another pandemic in the long term.

The current flu vaccination tackles seasonal flu and just four influenza strains but doesn't provide protection against new strains that could develop into a pandemic threat. Scientists have, for decades, attempted to create a vaccine that would be able to treat all 20 influenza strains to no avail.

The potential flu vaccine was purposely matched with imperfect viruses that could be the beginning of a new flu strain that causes a pandemic strain. It still provided strong protection. The next step in developing the flu vaccine will be to test it on monkeys and people.

Development of the vaccine comes as the US sees its highest levels of hospitalizations from influenza in a decade for this time of year, according to Rochelle Walensky, director of the Centers for Disease Control and Prevention, or CDC. At least 20,000 people were hospitalized with the flu for the week to Dec 3.

Scientists said that a trial of the potential vaccine tested on mice and ferrets was successful. It may also be modified to protect against COVID-19. The vaccine uses mRNA like the COVID-19 vaccines made by Pfizer-BioNTech and Moderna.

Scott Hensley, an immunologist at the University of Pennsylvania who led the work, wrote last month in the Science Journal magazine: "Because we cannot currently predict which subtype of the influenza virus will cause the next pandemic, researchers have made various attempts to produce a 'universal' vaccine that could protect people from a wide swathe of subtypes.

"This vaccine elicited high levels of cross-reactive and subtype-specific antibodies in both mice and ferrets, which protected these animals from matched and mismatched influenza virus strains," Hensley said.

This year, cases of the flu, RSV and COVID-19 have stretched hospitals and staff resources. The CDC said that 31 states, major cities and territories reported having "very high" levels of the flu and 16 others reported "high" levels.

Fourteen children have died so far this flu season. There have been at least 8.7 million illnesses, 78,000 hospitalizations and 4,500 deaths from it so far this season, according to CDC estimates.

'Circulating more widely'

"Influenza virus is really out there circulating much more widely than it would be normally," William Schaffner, professor of preventive medicine and infectious diseases at Vanderbilt University Medical Center in Nashville, Tennessee, told China Daily.

"This is a vigorous winter respiratory virus season. And we could have concurrent coincidental flu and COVID increases, which once again, could strain our healthcare system substantially."

Walensky said that vaccination rates for people at higher risk from the flu — those 65 and older, children and pregnant women — are lower than at this time last year.

Sandra Fryhofer, an internist who chairs the American Medical Association board, urged people to get flu shots now.

"This year's flu season is off to a rough start," Fryhofer said in a call to reporters alongside Walensky. "It started early, and with COVID and RSV also circulating, it's a perfect storm for a terrible holiday season."

belindarobinson@chinadailyusa.com