Why are fears of a 'tripledemic' arising?

Cases of three major respiratory viruses — influenza, Covid-19 and RSV — are on the rise in the United States, pushing the country toward a feared “tripledemic” in its first post-pandemic respiratory virus season.

Hopes were high as America heads into virus season this fall. The national arsenal against these viruses included vaccines against RSV for the first time, newly updated COVID-19 vaccines, and the history of flu “immunity credit” affecting children in 2022.

But now hope is waning. Access to a vaccine for RSV, or respiratory syncytial virus, has been a struggle for many, and enthusiasm for new COVID-19 vaccines has turned sour. COVID-19 hospital admissions have been on the rise since November and most sites — 69 percent — of wastewater testing are seeing large increases in virus levels.

According to the latest update from the Centers for Disease Control and Prevention (CDC), flu activity across the country is currently “elevated and continuing to increase in most parts of the country”. Flu vaccination uptake appears to be lagging, with nearly 8 million fewer people vaccinated in mid-December compared to the same period in 2022, according to the CDC.

In the first two years of the pandemic, flu activity was low, largely due to the precautions communities took to mitigate the spread of the Covid virus. The 2022-23 flu season marks a return to normal flu conditions.

Only a fifth of US adults say they have received the new COVID-19 shot Poll from KFF. The uptake of earlier bivalent shots was similarly low and many Americans have not received the vaccine since receiving the first doses in 2020 or 2021.

“We're definitely seeing an increase in the number of cases of Covid-19 flu. They're both on the rise right now,” said Louis Ostroski, chief of infectious diseases and epidemiology at UTHealth Houston and Memorial Hermann.

Speaking about RSV cases he's seen in the Houston area, Ostroski said infections spiked in December, though he's still seeing “steady” numbers.

“It's so dangerous, it prompted the CDC to send out a health alert by the end of December, reminding all doctors to really work on getting patients vaccinated and when they have symptoms, they can access treatment if they need it.” Ostrosky noted.

RSV data available from the CDC show that test positivity peaked in late November, with positive rates for antigen and PCR tests beginning to decline in recent weeks.

Hopes are high that the approval of two RSV vaccines for seniors and a preventive monoclonal antibody for children will help keep cases low this season.

But Sanofi, the maker of the monoclonal antibody Beyfortus, said in October that “unprecedented demand” led to shortages, leading the CDC to advise doctors to allocate doses to their high-risk patients.

RSV vaccine uptake appears to slow among seniors, With CDC data Only about 10 percent of nursing home residents were immunized against the virus in mid-December.

“The numbers are not good,” said Marcus Plescia, chief medical officer of the Association of State and Territorial Health Officials, of the three circulating viruses.

“When we get some new numbers over the last week, I think it will be continued trends in the same direction and increased activity in all of those conditions,” Plescia said.

After weeks of year-end travel, holiday “pump” events are expected. AAA rated in December More than 115 million people Travel 50 miles or more from home during holidays in the US.

Amidst all the travel, Plescia lamented that the social norms he believed had become commonplace following the pandemic seemed to be largely abandoned.

“I think we're going back to, you know, people not staying home when they're sick,” Plessia said. “And they think it's a small thing and it doesn't really occur to them that they could be affecting somebody else.”

While Plescia noted that many hospital settings are bringing back mask requirements amid the rise in respiratory viruses, masking has also become rare again. These hospital-enacted requirements may be more easily accepted by communities than those issued by the government, and Plessia expects to see more of them in the future.

While cases are on the rise, Blascia said his organization has yet to hear of any healthcare systems across the country being unduly stressed by the respiratory virus situation.

“The number one concern about this being kind of a 'tripledemic' is that so many people will get sick that hospitals will be overwhelmed because they don't have enough beds or because they don't have enough staff. That number of people. We don't hear that we're approaching it, but that's what we're most worried about,” he said.

Ostrosky is optimistic case rates will begin to decline soon after the potential holiday bump, with last winter's peaks indicating a drop sometime in early January. He emphasized that since there are now many treatments available to treat these infections, it's still worthwhile to get tested if you're experiencing symptoms.

Going forward, Blascia also suggested that there should be a greater focus on vaccinations among healthcare workers.

“It's important because we don't want healthcare workers to get sick and pass it on to their patients, but you know, when you have a lot of healthcare workers getting sick, this whole capacity thing gets complicated,” Blascia said.

“Because what we're hearing now is that hospitals are less concerned about not having enough beds. They are more concerned about having enough health workers to staff those beds.