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.

Australia issued a health advisory warning travellers and healthcare providers about counterfeit batches of a rabies vaccine that have reportedly been circulating in India since November 1, 2023. The alert has raised concerns for anyone who may have received the vaccine while travelling or living in the country.

This Is What The Australian Advisory Says:

The warning was issued on December 22 by the Australian Technical Advisory Group on Immunisation. It flagged counterfeit batches of the rabies vaccine Abhayrab. While the vaccine is not supplied or used in Australia, the advisory notes that Australians or other travellers who were vaccinated in India could still be at risk.

The advisory clearly states that people who may have received the counterfeit vaccine might not be fully protected against rabies. As a precaution, it recommends that they receive replacement doses using a rabies vaccine that is registered and approved for use in Australia.

As it can be difficult to verify whether a dose was genuine or fake, the advisory takes a cautious approach. It says that anyone who received Abhayrab in India on or after November 1, 2023, should be considered as potentially having been given a counterfeit vaccine. Such individuals should be offered replacement doses as per Australian guidelines.

Why rabies protection is critical

Rabies is a viral zoonotic disease that attacks the central nervous system. In humans, it is most commonly transmitted through the bite of an infected dog. According to the World Health Organization (WHO), once rabies reaches the central nervous system and symptoms begin to appear, the disease is fatal in almost all cases.

India continues to bear a significant burden of the disease. WHO estimates suggest that rabies causes between 18,000 and 20,000 deaths every year in the country. India alone accounts for about 36 percent of rabies deaths globally, making effective vaccination and timely treatment especially critical.

Vaccine manufacturer responds

Abhayrab is manufactured by the Human Biologicals Institute, which is a division of Hyderabad-based Indian Immunologicals Limited. Responding to the advisory, the company said that it had proactively identified an issue in January related to a specific batch of the vaccine, as reported by Scroll.

According to the company, the issue involved Batch Number KA 24014, which was found in the marketplace with packaging that differed from the original. Indian Immunologicals Limited said it immediately informed Indian regulators and has been working closely with regulatory authorities and law enforcement agencies to address the issue. A formal complaint has also been lodged to support an investigation.

The company stressed that every batch of vaccine it produces is tested and released by the Central Drugs Laboratory under the Government of India before being made available for public use.

Broader concerns around medical quality

The advisory also comes at a time when India-made medical products have faced scrutiny abroad. In recent years, deaths allegedly linked to Indian-manufactured cough syrups were reported in countries like Gambia and Uzbekistan. Separately, Indian-made eye drops were suspected to be linked to infections in Sri Lanka.

Read: After Coldrif, WHO Bans 2 More Drugs, But This Is Not the Only Death from Indian Cough Syrup

Indian Immunologicals Limited, however, reiterated its commitment to safety and quality. It noted that Abhayrab has been manufactured since 2000, with over 210 million doses supplied in India and more than 40 countries. The company said the vaccine holds nearly 40 percent of the market share and assured healthcare professionals and the public that supplies made through authorized distributors are safe and meet quality standards.

Millie Bobby Brown has built an impressive career, all while quietly managing a few health concerns along the way. From becoming a household name through Netflix’s hugely popular Stranger Things to leading films like Enola Holmes, the Gen Z actor (now a married mother of one) has made a strong mark in Hollywood. What many people may not realise is that her work has, at times, been shaped by a hearing-related condition. Brown has lived with hearing loss for most of her life, a fact that often goes unnoticed.

Millie Bobby Brown Reveals Having Unilateral Deafness

Brown first spoke publicly about her hearing condition in a 2017 interview with Variety, where she shared that she has had hearing loss in one ear since birth. Even early in her career, she was clear that she would not allow it to stand in the way of her passion for performing. “I just started to sing, and if I sound bad I don’t care, because I’m just doing what I love,” she said at the time. “You don’t have to be good at singing. You don’t have to be good at dancing or acting. If you enjoy it and it makes you happy, you should do it.”

While Brown rarely focuses on her hearing loss, she has spoken about how it affects her daily life. In a conversation with Call Her Daddy host Alex Cooper, she explained that certain sounds, like loud chewing, do not bother her because she can mostly hear herself when she eats. She also shared that her husband, Jake Bongiovi, whom she married in 2022, sometimes jokes that she has “selective hearing.” In reality, she says sounds often feel “muffled, like being underwater.” Brown admitted that she does miss important moments, including hearing directors call out “action” or “cut” on set.

What Is Unilateral Deafness?

Unilateral hearing loss happens when hearing is affected in one ear while the other ear functions normally. Even with hearing in one ear, this condition can make it difficult to understand speech clearly and to identify where sounds are coming from.

The level of hearing loss in one ear can range from mild to severe. When there is little to no hearing at all in one ear, it is described as severe or profound hearing loss, also known as single-sided deafness. Unilateral hearing loss may be present at birth, develop gradually, or appear suddenly. Depending on the cause, options such as hearing aids or cochlear implants may help improve hearing, according to the Cleveland Clinic.

Unilateral Deafness: What Are The Symptoms?

Many symptoms of unilateral hearing loss are similar to those seen with hearing loss in both ears. You may:

• Ask people to repeat what they’ve said
• Increase the volume on your television, laptop, or phone
• Struggle to follow conversations, especially in noisy places like restaurants or busy workplaces
• If hearing is affected in only one ear, tinnitus, or ringing, may occur on that side alone. You may also notice that you tend to rely more on one ear when speaking on the phone or listening to others.
• Although unilateral hearing loss often develops slowly, it can also happen suddenly. If you experience a sudden loss of hearing in one ear, it’s important to seek medical advice promptly.

What Causes Unilateral Hearing Loss?

Doctors do not yet fully understand all the reasons why hearing loss occurs in just one ear. Causes can differ between adults and children. In children, hearing loss may be linked to genetics or infections. Possible causes include:

• Noise-related hearing damage
• Certain inherited conditions, such as neurofibromatosis Type 2, which can lead to acoustic neuromas in one ear
• Head injuries
• Traumatic brain injury (TBI)

Unilateral Hearing Loss: Is There Treatment Available?

According to the American Academy of Audiology, treatment depends on the underlying cause and the severity of the hearing loss. Available options may include:

• Hearing aids: These are typically worn to support sound perception when one ear is affected
• Contralateral routing of signal (CROS) devices: This setup uses two devices. One acts as a microphone on the non-hearing side and sends sound to a hearing aid worn on the functioning ear
• Cochlear implants: These may help restore hearing in the affected ear and improve speech understanding and sound awareness
• Bone-anchored hearing aids: These devices transmit sound from the non-hearing ear to the hearing ear through bone conduction
• Frequency modulation (FM) systems: FM systems use radio signals to send sound directly from a microphone to a receiver, such as a hearing aid worn on the non-hearing ear

In what researchers are calling an important scientific advance, a team in the US has shown through animal experiments that Alzheimer’s disease may be reversible, overturning a belief that has shaped medical thinking for more than 100 years. For generations, the neurodegenerative condition was considered permanent and progressive. The findings, published in Cell Reports Medicine, are based on multiple preclinical mouse models as well as examinations of human Alzheimer’s brain tissue.

The study found that preserving a healthy balance of NAD, a molecule central to cellular energy production, could both prevent and reverse Alzheimer’s-related damage. NAD plays a key role in brain function and is now seen as a major contributor to the disease process. Researchers also observed that NAD levels drop much more sharply in the brains of people with Alzheimer’s, a pattern that was mirrored in mouse models of the condition.

Don't Miss: Taking Tramadol? Scientists Warn It May Cause More Harm Than Relief

Alzheimer’s Disease Can Be Reversed, New Study Shows

“We were extremely encouraged by what we observed,” said Andrew A. Pieper, the study’s senior author and Director of the Brain Health Medicines Center at the Harrington Discovery Institute, University Hospitals, as per Sciencedirect. “By restoring the brain’s energy balance, we saw both structural and functional recovery in mice with advanced Alzheimer’s.”

Pieper noted that the effect appeared consistently across two very different mouse models, each driven by separate genetic mechanisms linked to Alzheimer’s in humans. “Seeing recovery in models caused by distinct genetic pathways strengthens the case that restoring NAD balance in the brain could have real therapeutic potential for patients,” he said.

For the study, researchers examined mice engineered to carry genetic mutations known to cause Alzheimer’s disease in people. One group of mice carried multiple human mutations affecting amyloid processing, while the second group carried a human mutation in the tau protein.

After confirming that brain NAD levels dropped sharply in both human Alzheimer’s tissue and mouse models, the team tested whether stopping this decline before symptoms appeared could prevent disease, and whether restoring NAD levels after the disease had progressed could reverse it. To do this, they used a well-studied drug called P7C3-A20 to restore NAD balance in the brain.

The results were striking. Not only did maintaining NAD levels prevent Alzheimer’s from developing in mice, but starting treatment later, after the disease was already advanced, allowed the brain to repair the main pathological damage caused by the genetic mutations. In both mouse models, cognitive abilities were fully restored.

What Is NAD In Alzheimer’s?

In Alzheimer’s disease, NAD, short for nicotinamide adenine dinucleotide, is an essential coenzyme whose levels naturally decline with age. This decline disrupts energy production, mitochondrial health, DNA repair, and the ability of neurons to withstand stress. Research suggests that increasing NAD levels, often through precursors such as nicotinamide riboside, may reverse Alzheimer’s-related damage, improve memory, and correct abnormal RNA processing in animal models. Because of this, NAD has become a major area of focus for developing new Alzheimer’s therapies, according to the National Institutes of Health.

Why NAD Is Important In Alzheimer’s

• Energy and Mitochondria: NAD is necessary for producing ATP, the cell’s main energy source, and for keeping mitochondria functioning properly, both of which are critical for healthy brain cells.
• Cellular Stress: NAD supports neurons in responding to and surviving stress. When NAD levels fall in Alzheimer’s, these protective mechanisms weaken.
• DNA Repair: NAD is involved in repairing DNA damage, which increases as amyloid-beta accumulates in the brain. Low NAD levels interfere with this repair process.
• RNA Splicing: Emerging research shows that NAD may help correct faulty RNA splicing events linked to Alzheimer’s. This process may involve a protein called EVA1C and could contribute to improved memory and better clearance of harmful proteins.

Next Steps Toward Human Trials

The findings also pave the way for further research and eventual testing in people. The technology behind the treatment is currently being developed for commercial use by Glengary Brain Health, a Cleveland-based company co-founded by Dr. Pieper.

“This recovery-based treatment approach now needs to be tested in carefully designed clinical trials to see if the benefits seen in animals can be replicated in humans,” Pieper said.

He added that future laboratory work will focus on identifying which components of brain energy balance matter most for recovery, exploring additional strategies that could complement this approach, and determining whether similar methods could work for other long-term, age-related neurodegenerative diseases as well.