Enlarge / A microscope image of Streptococcus pyogenes , a common type of group A strep. (credit: Getty | BSIP )

In the wake of the COVID-19 pandemic and amid a tall wave of respiratory viruses, health officials in Colorado and Minnesota documented an unusual spike in deadly, invasive infections from Streptococcus bacteria late last year, according to a study published this week by the Centers for Disease Control and Prevention .

The spike is yet another oddity of post-pandemic disease transmission, but one that points to a simple prevention strategy: flu shots.

The infections are invasive group A strep , or iGAS for short, which is caused by the same group of bacteria that cause relatively minor diseases, such as strep throat and scarlet fever. But iGAS occurs when the bacteria spread in the body and cause severe infection, such as necrotizing fasciitis (flesh-eating disease), toxic shock syndrome, or sepsis. These conditions can occur quickly and be deadly.

Enlarge / An electron micrograph of norovirus. (credit: Getty| BSIP )

While cold-weather waves of flu, RSV, and COVID-19 are on a merciful decline, another common pathogen seems to be having its moment: norovirus.

The percentage of positive norovirus tests at the end of January has surpassed the peak percentage seen last year in March, according to surveillance data collected by the Centers for Disease Control and Prevention. Though the data suggests the virus may have peaked on a national level, regional data shows cases are still floating upward in the Northeast, Midwest, and Western US, with numbers in the South seemingly sinking.

Norovirus test positivity. (credit: CDC )

Like many infectious diseases, norovirus cases bottomed out amid the pandemic health restrictions and disruptions. But in 2022, the US saw a resurgence to pre-pandemic levels—and by one metric, surpassed them. The CDC's Norovirus Sentinel Testing and Tracking (NoroSTAT) network, which collects data on norovirus outbreaks from 14 collaborating state health departments, reported that the number of norovirus outbreaks at the end of February 2022 hit a season peak exceeding that of any previous season since surveillance began in 2012.

Enlarge (credit: DeFodi Images )

Moderna's mRNA-based vaccine against RSV (respiratory syncytial (sin-SISH-uhl) virus) was effective at preventing disease in older adults, according to preliminary, top-line results of an ongoing phase III clinical trial the company announced Tuesday . Moderna said it will now seek regulatory approval for the vaccine in the first half of this year.

According to the company, the vaccine was 83.7 percent effective at preventing RSV-associated lower respiratory tract disease (RSV-LRTD) involving two or more symptoms in adults age 60 and over. It was 82.4 percent effective at preventing RSV-LRTD with three or more symptoms in the same group. No safety concerns were identified.

The findings are another positive sign for mRNA vaccine platforms generally, which Moderna and other pharmaceutical companies have quickly shifted to for fighting various other infections and diseases given the global success of mRNA-based COVID-19 vaccines. mRNA-based vaccines are now in development for everything from seasonal flu to HIV and certain cancers.

Enlarge (credit: Aurich Lawson / Getty)

Three years into the pandemic, COVID-19 is still going strong, causing wave after wave as case numbers soar, subside, then ascend again. But this past autumn saw something new—or rather, something old: the return of the flu. Plus, respiratory syncytial virus (RSV)—a virus that makes few headlines in normal years—ignited in its own surge, creating a “tripledemic.”

The surges in these old foes were particularly striking because flu and RSV all but disappeared during the first two winters of the pandemic . Even more surprising, one particular version of the flu may have gone extinct during the early COVID pandemic. The World Health Organization’s surveillance program has not definitively detected the B/Yamagata flu strain since March 2020. “I don’t think anyone is going to stick their neck out and say it’s gone just yet,” says Richard Webby, a virologist at St. Jude Children’s Research Hospital in Memphis. But, he adds, “we hope it got squeezed out.” Such an extinction would be a super rare event, Webby says.

But then, the past few years have been highly unusual times for human-virus relations, and lockdowns and masks went a long way toward preventing flu and RSV from infiltrating human nostrils. Still, Webby thinks another factor may have kept them at bay while COVID raged. It’s called viral interference, and it simply means that the presence of one virus can block another.

Enlarge / An intensive care nurse cares for a patient suffering from respiratory syncytial virus (RSV), who is being ventilated in the children's intensive care unit of the Olga Hospital of the Stuttgart Clinic in Germany. (credit: Getty | picture alliance )

With SARS-CoV-2 still circulating and seasonal viruses, including influenza and RSV, making up for lost time during the pandemic, the US is getting slammed by respiratory illnesses. And things could get worse as more holidays and associated gatherings approach, health officials warned Monday.

"This year's flu season is off to a rough start. Flu's here, it started early and with COVID and RSV also circulating, it's a perfect storm for a terrible holiday season," Sandra Fryhofer, chair of the American Medical Association and adjunct medicine professor at Emory University School of Medicine, said in a press briefing held by the Centers for Disease Control and Prevention today. "Over the last few years, COVID-protective measures also prevented spread of flu and other respiratory infections, but we're really no longer in that bubble."

Cases of influenza-like illnesses (ILIs) are soaring throughout the country , with 47 states seeing "very high" or "high" activity levels, according to the latest CDC data. The agency estimates that there have been at least 8.7 million illnesses, 78,000 hospitalizations, and 4,500 deaths from flu.

Enlarge / Parents work on their computers while their son entertains himself at their home in Boston in April 2020. (credit: Getty | Boston Globe )

Respiratory illnesses are raging this fall, slamming children particularly hard. Cases of influenza-like illnesses are off to a startlingly strong and early start this season. RSV—respiratory syncytial (sin-SISH-uhl) virus—continues to skyrocket. A stew of SARS-CoV-2 variants is still simmering in the background. And the rabble of usual cold-season viruses, such as rhinoviruses and enteroviruses, is also making the rounds.

RSV national trends. (credit: CDC )

With the surge in infections, children's hospitals around the country have reported being at capacity or overwhelmed, as Ars has reported before. But another effect of the crush of viruses is a squeeze on the workforce. As The Washington Post first reported Tuesday , the US broke its record last month for people missing work due to childcare problems—such as having children home sick and childcare facilities or schools shuttered due to staffing shortages and sickness.

Outpatient respiratory illness visits. (credit: CDC )

In October, more than 100,000 employed Americans missed work for childcare-related problems, according to data from the US Bureau of Labor Statistics . That is more missing workers than in any other month in recent records, including the entirety of the COVID-19 pandemic, during which many childcare facilities and schools closed down for extended periods. At the height of pandemic-related shutdowns in 2020, the number of Americans missing work for childcare problems only reached the low 90,000s.

Enlarge (credit: CDC )

The US continues to see a dramatic and early surge in respiratory illnesses, which is hitting young children particularly hard and setting records for the decade.

The Southeast region is the most affected by the surge, which is driven by cases of flu, RSV (respiratory syncytial (sin-SISH-uhl) virus), and other seasonal respiratory viruses. Seven southern states—Alabama, Georgia, North Carolina, South Carolina, Mississippi, Tennessee, and Virginia—have reached the highest level of respiratory-illness activity on the scale from the Centers for Disease Control and Prevention. The states are colored a deep purple on the national map, representing the highest of sub-level of "Very High" activity.

Overall, 25 states are experiencing "High" or "Very High" levels of respiratory illness activity, while six have reached the moderate category.

Enlarge / An isolation tent for an emergency department in Walnut Creek, California, in March 2022. (credit: Getty | Gado )

Although COVID-19 remains in a lull, hospitals across the country are in crisis amid a towering wave of seasonal respiratory illnesses—particularly RSV in children—as well as longer-term problems, such as staffing shortages.

Pediatric beds are filling or full, people with urgent health problems are waiting hours in emergency departments hallways and even parking lots, and some hospitals have pitched outdoor tents, conjuring memories of the early days of the pandemic.

In one of the most striking examples, the emergency department of a Seattle-area hospital became so overwhelmed last month that the department's charge nurse called 911 for help , telling the fire department that they were "drowning" and in "dire straits." There were reportedly over 45 people in the department's waiting room and only five nurses on staff.

Enlarge / An intensive care nurse cares for a patient suffering from respiratory syncytial virus (RSV), who is being ventilated in the children's intensive care unit of the Olga Hospital of the Stuttgart Clinic in Germany. (credit: Getty | picture alliance )

As an unusually large and early seasonal surge of RSV cases inundate children's hospitals around the country, pharmaceutical giant Pfizer offered a glimmer of hope Tuesday in the form of top-line, phase three clinical trial results.

The company's experimental RSV vaccine—given to pregnant trial participants—was 82 percent effective at preventing severe RSV-related lower respiratory tract illness in the first three months of an infant's life. It was 69 percent effective over the first six months, Pfizer announced.

“We are thrilled by these data as this is the first-ever investigational vaccine shown to help protect newborns against severe RSV-related respiratory illness immediately at birth,” Pfizer Chief Scientific Officer Annaliesa Anderson said in a statement.