There's been an alarming increase of respiratory and gastrointestinal viruses in the United States lately, causing anxiety about a so-called "quad-demic". According to surveillance reports, influenza, COVID-19, RSV and norovirus are at very high levels everywhere. While the surge aligns with patterns typical for this season, several epidemiologists view simultaneous infections of such proportions to pose risks not only to individual healthcare but public health.

The incidence of the quad-demic should vary with seasonal patterns, vaccination rates, and public health interventions. Each virus alone is relatively easy to manage; however, the effect of all together could lead to overburdening of health care facilities and increase risks for those at higher risk. Continuing surveillance, early testing, and proactive prevention measures will play an important role in the control of these infections going forward.

While the term "quad-demic" sounds daunting, it must be taken into perspective. For years, we have had all these viruses together, and we have the capabilities to mitigate some of the risk. Vaccination, proper hygiene and using common sense helps individuals get through the season unscathed. Is the quad-demic a permanent fixture or just another seasonal wave? Let's break this down.

What is the Quad-demic?

Typically, flu, COVID-19, and RSV have been the primary culprits behind seasonal respiratory infections. However, norovirus, a highly contagious stomach bug, has emerged as a fourth significant player, inducing fears of a more severe and widespread viral outbreak. According to the Centers for Disease Control and Prevention (CDC), the U.S. recorded nearly 500 norovirus outbreaks between August and December 2023, a substantial rise from the previous year’s numbers.

While the term "quad-demic" may sound ominous, the seriousness and consequences of such infections should be weighed in light of the U.S. healthcare system's experience with managing viral surges since the start of the COVID-19 pandemic.

1. Influenza (Flu)

Flu continues to be one of the most common and alarming seasonal illnesses. In the period spanning from 2023 to 2024, there were approximately 40 million cases of flu, and thousands of hospitalizations along with reported 47 deaths have been reported this season. Flu symptoms include fever, chills, cough, sore throat, muscle pain, and fatigue, with most recovering within a week or two but risky factors for severe illness effects occur in young children, elderly, and people with chronic conditions.

2. Covid-19

Despite its reduction from the first pandemic peak, COVID-19 is still rampant. The CDC estimates that alone between October and December 2023, there were between 2.7 and 5 million cases in the U.S. Hospitalization has increased by cities such as Los Angeles, Chicago, and New York. Symptoms are closely similar to the flu, fever, cough, and fatigue but uniquely presents in some cases as loss of taste and smell.

3. RSV

RSV is the most common cause of lower respiratory infections in infants, older adults, and immunocompromised individuals. While RSV peaked late in 2023 and early 2024, it continues to be a threat because it can lead to bronchiolitis and pneumonia. It is very similar to the common cold, presenting with symptoms such as congestion, runny nose, coughing, and fever, which can make it difficult to differentiate from flu or COVID-19 without testing.

4. Norovirus

Norovirus, also called the "stomach flu," is a highly contagious infection of the gastrointestinal tract, not a respiratory virus. It transmits quickly from contaminated food and water and contact with contaminated surfaces, causing such symptoms as diarrhea, vomiting, nausea, and stomach pain. Cases have shot up, the CDC said Monday, with reports of outbreaks surging compared with last year.

Is There a Challenge In Diagnosis Due to Overlapping Symptoms?

The greatest challenge during the quad-demic is how the four viruses are alike and thus make identification very hard with no testing applied. Most cases present symptoms common to all viruses: fever, tiredness, body pains, and respiratory, which includes coughing and congestions for influenza, COVID-19, and RSV; the other would be norovirus symptoms as nausea and vomiting can appear even in extreme influenza and COVID-19. This overlap increases the risk of misdiagnosis and delayed treatment, hence the need for early testing and proper medical guidance.

Also Read: Is US Preparing For A Quad- demic 2025?

Effective Prevention Strategies That Work

The best defense against these viruses is a combination of vaccines, hygiene, and lifestyle precautions. While lifestyle modifications are highlighted as part of the constant need to eat healthy, ensure daily movement and drinking adequate amount of fluids. There is a sure short two preventive strategies that are effective:

Vaccination

• Flu vaccine: Annual flu shots reduce the severity of infection, allergic flare ups and hospitalizations.
• COVID-19 vaccine: Though COVID-19 cases have declined, vaccination remains critical in preventing severe outcomes.
• RSV vaccine: Available for those aged 60 years and older, especially those with underlying conditions.
• Norovirus vaccine: No vaccine is yet available, but mRNA vaccine research is in progress.

Hygiene and Sanitation

• Washing hands frequently with soap and water for at least 20 seconds, especially after public exposure.
• Disinfect frequently touched surfaces regularly, use sanitiser when outside.
• Avoid close contact with infected people and wear masks.

Do You Need To Wear A Mask All The Time?

While debates on masked wear continue on, experts on mask-wear affirm that this does not only have a historical precedent but works towards reducing airborne viruses spreading within the environments. Hospitals, though, ensure masking in key sections of themselves. Publicized mask-wear remains a discretion, though massing indoors still goes a longer way in cases like peak flu seasons.

If you notice the symptoms of these viruses, then it's best to be confined at home and avoid having face-to-face interaction with others and seek immediate attention from your physician if your condition worsens. Quarantining for some days can decrease the spread of infection.

As we move into the first half of 2025 and beyond, staying informed and proactive is the best strategy for maintaining health and avoiding unnecessary panic. The key takeaway? Stay vigilant, but don’t be alarmed—these viruses are here, but so are the means to fight them.

Jesy Nelson, former Little Mix singer, 34, and her fiancé, Zion Foster welcomed their twins, Ocean Jade and Story Monroe Nelson-Foster were devastated when the doctors broke the news that "they are probably never going to be able to walk, they probably will never regain their neck strength, so they will be disabled". Both the twins were diagnosed with SMA-1, a rare disease, known as the spinal muscular atrophy type 1.

Zion, 27, shared a poem for his eight-month-old warrior little girls. The Sun reported, he said: "They said it’s unlikely you’ll walk, you may not be able to talk, probably won’t be able to hold your head up, that’s what me and Jesy heard – SMA Type 1.

And it became so clear, doctors only go near what they can measure, so what’s certain?

I watch your smiles like sunsets, not promised, but real. I listen to you babble the sweetest melodies, in the moment it makes me wonder, if I keep telling you who I want you to be, what I want you to do, what I expect from you, am I loving you, or am I loving my fear?

If I take you for how God knitted you, just as you are, nothing removed, am I loving you? Am I accepting you?

Story, is your heart okay? Ocean, how’s your mind? I hear strength in your lungs every time you cry, two little warrior girls who already know how to fight.

Honestly, my worry isn’t the milestones, isn’t forcing life to live a different way. My worry is quieter than that, deeper. It’s about accepting you, loving you for who you are right now, without conditions.

No matter what tomorrow brings, and no matter what yesterday was."

What Treatment Jesy Nelson's Daughter Are Undergoing?

Jesy said, "They have had their treatment, thank God. A one-off infusion. That puts the gene back in their body that they don't have. It stops the muscles still working from dying. Any that have gone you can't regain them back."

While she does not reveal the name of the treatment, it is a single dose gene treatment, where patients receive an intravenous adeno-associated virus stereotype 9 carrying SMN complementary DNA encoding the missing SMN protein, as mentions a 2017 study published in The New England Journal of Medicine, or the Zolgensma, a prescribed gene therapy used to treat children less than 2 years old with SMA.

“Now it’s down to constant physio. We’ve been told they’ll probably never walk or regain their neck strength. They’ll probably be in wheelchairs.”

Also Read: Former Little Mix singer Jesy Nelson's Twin Babies Have SMA-1; Signs She Is Asking Other Parents To Look Out For

Jesy Nelson Twins: What Is SMA-1?

SMA-1. a rare disease, known as the spinal muscular atrophy type 1 or the Werdnig-Hoffmann disease is when the muscle weakness appears at birth or within the first six months. This rare condition prevents infants from sitting unassisted and causing severe breathing, swallowing, and sucking difficulties, leading to a poor prognosis without aggressive support. This condition has impacted the twin babies of the former Little Mix singer Jesy Nelson. Her twin babies may never be able to walk. However, she said that her babies will "fight all the odds" after they were being diagnosed with such a rare genetic condition.

Nelson said that there could be some common signs to look out for, which includes floppiness, inability to hold yourself up without support, a "frog-like" positioning of the legs without much movement, and rapid breathing in the tummy.

"If anyone is watching this video and they think they see these signs in their child, then please, please take your child to the doctor, to the hospital, because time is of the essence, and your child will need treatment. And the quicker you get this, the better their life will be," she added.

Flu cases are starting to fall, yet experts caution that the United States still faces risks. In the week ending January 10, fifteen more children died from the flu, bringing the total pediatric deaths this season to 32, as per NBC News.

Flu Season: Latest CDC Data

On Friday, the Centers for Disease Control and Prevention (CDC) reported an 18% drop in confirmed flu cases compared with the previous week. Visits to doctors for respiratory illnesses decreased by more than 5%, and hospitalization rates fell by nearly 55%. Influenza-related deaths, however, rose by 2%.

So far this flu season, the CDC estimates that 18 million people have been infected, including 230,000 hospitalizations and 9,300 deaths.

“It seems like there is some cautious good news that cases are declining,” said Jennifer Nuzzo, director of the Pandemic Center at Brown University School of Public Health. “But I’m going to put a giant asterisk on this because that does not mean the worst is behind us.”

Last year, flu cases dipped around this time before climbing again in early February.

Flu Season: State-by-State Variation

CDC data reflect a national trend, but not all states have necessarily reached their peak. “We are not going to all experience this at the same time,” said Beth Carlton, a public health professor at the University of Colorado, as per NBC News. “Nationwide, the trend is downward, but different states and communities may see spikes as the virus spreads.”

Flu often appears first in densely populated areas like New York City before moving to rural regions, but the virus can behave unpredictably.

Flu Season: Impact on Schools

Although flu cases may be falling overall, other winter illnesses such as norovirus, Covid, and strep throat are still causing school closures in states including Arkansas, Kansas, Kentucky, Tennessee, and West Virginia.

High flu activity continues in Idaho, New Mexico, New York, and parts of Appalachia, while Montana, South Dakota, Vermont, and Wyoming report lower case numbers.

“The number of people hospitalized for influenza around New Year’s was extremely high—the second highest in the past decade, with last year being the highest,” Carlton said.

Flu Season: A Difficult Flu Season

This year’s severe flu season is driven by a heavily mutated strain of influenza A called H3N2 subclade K. Its mutations make it less similar to the strain used in this year’s vaccine. Influenza-like illnesses, including RSV and Covid, are also unusually high, Nuzzo said.

“Typically these viruses peak at different times, but this year they are peaking together, making the season particularly harsh,” she noted.

While there were concerns that the vaccine would be less effective against subclade K, recent research shows the current flu shot still offers protection, particularly against hospitalization. The vaccine covers three strains: H1N1, H3N2, and one B strain.

Flu Season: Pediatric Risk

As per NBC News, last year marked the deadliest flu season for children since the CDC began tracking pediatric deaths, with 289 children dying—more than during the 2009 H1N1 pandemic.

“That double peak last season clearly had consequences,” Nuzzo said. “Any decline this season is welcome, but we can’t assume the worst is over.”

Among children eligible for the flu shot whose vaccination status was known, 90% of pediatric deaths occurred in unvaccinated kids.

Following recent CDC guidance, flu shots are no longer recommended for all children, a change from the previous advice that everyone six months and older should be vaccinated annually.

The Saudi Arabian Food and Drug Authority has cleared Anktiva, an IL-15–based immunotherapy created by billionaire physician-scientist Patrick Soon-Shiong and his biotech firm ImmunityBio, for the treatment of bladder cancer and lung cancer. This marks the first time the therapy has received national regulatory approval outside the United States.

The move signals an important global step for Anktiva, which currently holds a limited approval from the U.S. Food and Drug Administration. In the U.S., the drug is authorised only for patients with BCG-unresponsive, non–muscle-invasive bladder cancer (NMIBC) that includes carcinoma in situ. American regulators have so far resisted expanding its use to other bladder cancer subtypes. Saudi regulators, however, have adopted a broader stance, approving Anktiva for two cancer types under their domestic regulatory system.

What Is Anktiva?

Anktiva is an interleukin-15 receptor agonist designed to stimulate the body’s own immune defences. It works by activating and expanding natural killer (NK) cells and memory CD8⁺ T cells, which play a key role in immune surveillance. Unlike chemotherapy or gene-based treatments, Anktiva does not attack tumour cells directly. Instead, it boosts existing immune pathways to help the body recognise and destroy cancer cells.

ImmunityBio describes Anktiva as “the first FDA-approved immunotherapy that activates what’s called a natural killer cell to target and kill non-muscle-invasive bladder cancer cells.” In clinical practice, the drug is used alongside BCG (Bacillus Calmette-Guérin) in patients whose NMIBC has not responded to BCG alone. It is administered directly into the bladder through a catheter, followed by a structured maintenance schedule

Clinical Evidence Supporting FDA Approval in NMIBC

The FDA’s approval, issued on April 22, 2024, was based on results from a single-arm clinical study involving 77 patients with BCG-unresponsive stage 0 NMIBC. Participants received intravesical Anktiva combined with BCG, with maintenance therapy continuing for as long as 37 months.

The main efficacy results were as follows:

• Complete response rate: 62%

Durability:

• 58% of patients who responded remained disease-free for at least 12 months
• 40% stayed disease-free for 24 months or longer

For patients facing the prospect of radical cystectomy as the only curative option, these results were considered clinically significant. Still, the absence of a randomised control group has remained a point of contention among regulators and experts.

Regulatory Tension in the United States

Although the FDA approved Anktiva for NMIBC cases involving carcinoma in situ, it declined to extend the indication to patients with papillary-only disease. ImmunityBio pushed back against the decision, arguing that the same clinical data had already been deemed sufficient to support approval in a closely related patient group.

Rachel Sherman, MD, former principal deputy commissioner of the FDA, publicly criticised the agency’s stance, saying: “it is incomprehensible to me that the FDA refuses to file a supplemental BLA, stating the study is not sufficient to support a regulatory review, when it has already approved a product based on that very same study in essentially the same indication and population.”

The FDA has also expressed concerns about how the drug has been marketed. It issued a warning letter to ImmunityBio over promotional materials that cited survival benefits and cystectomy-avoidance rates not supported by robust evidence.

Saudi regulators, by contrast, have taken a more permissive view, approving Anktiva for both bladder and lung cancer and highlighting a willingness to act in areas of high unmet medical need.

With this decision, Saudi Arabia becomes the first country to approve Anktiva beyond NMIBC, potentially placing itself at the forefront of evaluating the therapy’s wider role across multiple cancer types.