The year 2025 served as a stark reminder that COVID is no longer the only illness demanding public attention. Over the months, several diseases resurfaced or intensified, some reaching epidemic levels. In many cases, the surge was driven by new variants that altered how these illnesses spread, how severe they became, and how quickly they overwhelmed health systems.

From respiratory infections to vector-borne diseases, 2025 showed how familiar pathogens can return in unfamiliar forms. Mutations made some infections more contagious, while others blurred early symptoms, delaying diagnosis and treatment. Below, we take a look at new variants of diseases that we witnessed in 2025.

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New Disease Variants That Emerged In 2025

COVID-19 New Variants

In 2025, fresh COVID-19 variants continued to circulate, most of them linked to Omicron sublineages. These strains spread quickly but, for many people, caused symptoms closer to a bad cold, flu, or seasonal allergies. Common symptoms included stomach issues, body pain, exhaustion, and fever.

Health authorities continued to advise testing through RAT or RT-PCR, short-term isolation, and medical care where needed. As with earlier waves, acting early made a clear difference in recovery and containment.

As per World Health Organization, some of the Covid variants that appeared in 2025 include:

XFG Variant

The XFG variant of COVID-19, also known as Stratus, surfaced in early 2025 as a recombinant strain. Recombinant variants form when two different COVID strains infect the same person and merge during mutation, a process that occurs naturally as viruses evolve. XFG drew attention because of how easily it spread and its ability to infect people despite previous infection or vaccination. Classified as a recombinant Omicron subvariant, XFG was detected widely across regions including North America, Europe, and Asia.

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According to WHO-linked data from mid to late 2025:

In the United States, XFG became the leading variant, responsible for around 85 percent of reported cases by the end of September 2025.

In the United Kingdom, XFG and related sublineages accounted for a sizeable share of infections, with reports suggesting nearly 30 percent of cases in July 2025.

In India, where XFG circulated by mid-2025, early clusters were largely reported from Maharashtra, followed by Tamil Nadu, Kerala, and Gujarat. It later emerged as the dominant strain in states such as Madhya Pradesh.

The nickname “Frankenstein” was informally attached to XFG because it combines genetic material from different Omicron subvariants. Experts from institutions like the Institute Pasteur and the University of Nebraska Medical Center noted that while it spreads rapidly, it has not been linked to more severe disease.

Omicron NB.1.8.1

NB.1.8.1, informally called “Nimbus,” is a distinct Omicron lineage that was first identified in early 2025. The World Health Organization classified it as a “Variant Under Monitoring” after noticing its steady global rise, particularly across parts of Asia and North America. Although it contributed to visible spikes in case numbers, there was no strong evidence that it caused more serious illness. Vaccines continued to offer reliable protection.

By mid-2025, NB.1.8.1 had become one of the faster-spreading Omicron offshoots, driving fresh COVID waves in several countries. Despite its speed, health agencies confirmed that existing vaccines remained effective and that the variant was not linked to increased severity. The WHO officially placed it under monitoring in May 2025.

Flu New Variants

H3N2 “Subclade K” Variant

The flu strain seen during the winter months of 2025 was identified as H3N2 subclade K, a seasonal influenza A virus. Some public commentary labelled it “super flu,” though this term has no medical basis and does not suggest the virus is inherently more dangerous or resistant to treatment. A key concern was that many people had limited prior exposure to this strain, resulting in lower community immunity. Flu vaccines, however, continued to protect against severe outcomes.

Data from NHS England showed a sharp rise in flu-related hospital admissions. During the first week of December, hospitals reported an average of 2,660 flu patients per day, marking a 55 percent increase from the previous week. The number of admissions was high enough to fill more than three entire hospital trusts.

Monkeypox New Variant

Clade LB Variant

Health authorities in England detected a new mpox variant after testing a person who had recently travelled to Asia, as per BBC. Genetic sequencing revealed that the strain was recombinant, combining elements of two circulating mpox types: clade 1, which is associated with more severe illness, and clade 2, which was responsible for the 2022 global outbreak.

The UK Health Security Agency stated that it was still evaluating the implications of this strain. While most mpox cases remain mild, officials advised people who qualify for vaccination to get immunised as a precautionary step.

Chikungunya New Variant

In 2025, Chikungunya did not see the emergence of a single newly named variant. Instead, there was a renewed spread of the East, Central, and South African genotype, particularly the Indian Ocean Lineage. This lineage has developed mutations that improve its ability to spread.

According to the National Institutes of Health, certain CHIKV lineages, including the E1-226A variant, previously helped shift infections into urban settings. More recent severe cases reported in India, including outbreaks in Pune in 2024, showed signs of neurological involvement such as paralysis and darkened nasal tissue. These symptoms are thought to be linked to mutations like E1-226V or A and E2-I211T, along with improved adaptation of the virus to Aedes aegypti mosquitoes, pointing to continued viral evolution aimed at more efficient transmission.

One child in India dies every nine minutes from an infection caused by antibiotic-resistant bacteria, as it becomes one of the top 10 global public health threats, experts warn.

Dr HB Veena Kumari of the Department of Neuromicrobiology, National Institute of Mental Health and Neurosciences, claims: "The Covid-19 pandemic has significantly contributed to rising antimicrobial resistance. The World Health Organisation projects that 10 million deaths will occur annually by 2025."

According to the National Foundation for Infectious Diseases, antibiotic resistance occurs when bacteria in the body learns to withstand and remain unaffected by the medicines (antibiotics) meant to kill them.

In such cases, doctors have to switch to different antibiotics, but these backup medicines might not work as well or might cause more side effects. Additionally, infections may also worsen over time as bacteria can become resistant to all available drugs.

Alarmingly is that these tough, drug-resistant bacteria can spread from one person to another, both in hospitals and at home.

According to Dr TS Balganesh, Gangagen Biotechnologies, nearly 36 percent of haemodialysis patients die from fatal infections, which is second only to cardiovascular diseases as a cause of death.

He tells Deccan Herald: "The risk for infective endocarditis in haemodialysis patients is approximately 18 times higher than in the general population and up to 58 percent of these episodes are caused by a bacteria named 'S aureus', with an in-hospital mortality of more than 50 percent."

What Does WHO Say?

One out of every six serious infections confirmed in labs worldwide last year could not be killed by the antibiotics meant to treat them.

Between 2018 and 2023, the problem of antibiotics failing (called resistance) got much worse. For many common types of germs, resistance went up by 5% to 15% every year. The growing inability of these essential medicines to work is a huge threat to people everywhere.

Which Antibiotics Are People Becoming Resistant To?

The WHO's latest report is the most detailed look yet at this issue. It reports on how much resistance exists across 22 different antibiotics, which include common drugs used to treat everyday illnesses. The report focused on eight common types of bacteria that cause things like:

• Urinary tract infections (UTIs)
• Stomach and intestinal infections
• Dangerous blood infections
• Gonorrhoea

Additionally, Dr Obaidur Rahman of Dr Ram Manohar Lohia Hospital has also warned that the country’s casual use of Azithromycin, sold under brand names such as Zithromax, Azee and Zmax, has worsened its effectiveness and pushed India closer to a major public health challenge.

A drug often prescribed for sore throats and upper respiratory tract infections, Dr Rahman noted that Azithromycin was once effective against Mycoplasma Pneumonia, a bacterium responsible for pneumonia in adults and children.

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However, this is no longer the case as India now shows an alarming 80 to 90 percent resistance to the drug when treating infections caused by this bacterium. A medicine that once addressed a wide range of respiratory problems is no longer reliable for many patients.

The surgeon has since urged people to avoid taking antibiotics without proper medical advice. Most seasonal respiratory infections resolve on their own, and unnecessary drugs only add to the resistance problem.

Supreme Court on Friday declared the right to menstrual health as part of the right to life under Article 21 of the Constitution. The court issued a slew of directions to ensure that every school provides biodegradable sanitary napkins free of cost to adolescent girls. The guidelines also ensured that schools must be equipped with functional and hygienic gender-segregated toilets. The Court directed the pan-India implementation of the Union's national policy, 'Menstrual Hygiene Policy for School-going Girls' in schools for adolescent girl children from Classes 6-12.

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Supreme Court Declares Menstrual Hygiene As Part Of Right To Life: Here Are the Directions

A bench comprising Justice JB Pardiwala and Justice R Mahadevan passed the following directions:

• All States/UT must ensure that every school, whether government-run or privately managed, in both urban and rural areas, is provided with functional gender segregated toilets with usable water connectivity.
• All existing or newly constructed toilets in schools shall be designed, constructed and maintained to ensure privacy and accessibility, including by catering to needs of children with disabilities.
• All school toilets must be equipped with functional washing facilities and soap and water available at all times.
• All states/UTs must ensure that every school, whether government-run or privately managed, in both urban and rural areas, provide oxo-biodegradable sanitary napkins manufactured in compliance with the ASTM D-6954 standards free of cost. Such sanitary napkins must be made readily accessible to girl students, preferably within toilet premises through sanitary napkin vending machines or, where not visible, at a designated place.
• All States/UTs must ensure that every school, whether government-run or privately managed, in both urban and rural areas establish menstrual hygiene management corners. It must be equipped with spare innerwears, uniforms, disposable pads and other necessary materials to address menstrual urgency.

The court also issued directions for the disposal of sanitary waste. Justice Pardiwala said, "This pronouncement is not just for stakeholders of the legal system. It is also meant for classrooms where girls hesitate to ask for help. It is for teachers who want to help but are restrained due to a lack of resources. And it is for parents who may not realise the impact of their silence and for society to establish its progress as a measure in how we protect the most vulnerable. We wish to communicate to every girlchild who may have become a victim of absenteeism because her body was perceived as a burden when the fault is not hers."

Read: Menstrual Cups To Replace Sanitary Napkins In Karnataka Government Schools

Why Is This Judgment So Important?

In India, menstruation is still seen as taboo. In fact, there is a lot of shame around it. Menstrual shame is the deeply internalized stigma, embarrassment, and negative perception surrounding menstruation, which causes individuals to feel unclean, or "less than" for a natural biological process. This judgment thus is an effort to do away with the shame rooted in cultural, social, and religious taboos, which is often the reason why many girls drop out, or due to lack of awareness, develop health adversities.

Most health videos on YouTube, even those made by doctors are also not reliable medical information, found a new study, published in JAMA Network Open. The researchers reviewed 309 popular YouTube videos on cancer and diabetes and found that fewer than 1 in 5 were supported by high quality scientific evidence. About two-thirds of the view had low, very low or no evidence at all to back up their health claims.

What was more concerning is that weaker evidence often attracted more viewer than those backed with strong science. The study looked at videos which had at least 10,000 views. The lead author of the study Dr EunKyo Kang of South Korea's National Cancer Center, said, "This reveals a substantial credibility-evidence gap in medical content videos, where physician authority frequently legitimizes claims lacking robust empirical support."

"Our findings underscore the necessity for evidence-based content-creation guidelines, enhanced science communication training for health care professionals, and algorithmic reforms prioritizing scientific rigor alongside engagement metrics," Kang added in a news release.

How Was The Study Conducted?

The researchers reviewed videos from June 20 and 21, 2025, focusing on cancer and diabetes content. 75 per cent of them were made by physicians. The videos had a median count of 164,000 views and a median length of 19 minutes.

Researchers also developed a scoring system, called E-GRADE to rate the strength of science backed evidence in each video's claim.

This is how the grading system worked:

• GRADE A: high quality evidence
• GRADE B: standard quality evidence
• GRADE C: low quality evidence
• GRADE D: very low or no evidence

What Were The Results Of The Medical Videos?

• GRADE A: 19.7%
• GRABE B: 14.6%
• GRADE C: 3.2%
• GRADE D: 62.5%

The study also found that videos with the weakest evidence were 35% more likely to get higher views than videos with strong scientific evidence.

Richard Saver, a professor of law at the University of North Carolina at Chapel Hill noted that this issue is not just limited to YouTube. "Physician-spread misinformation is a long-standing problem, dating back well before the internet era," he wrote in an accompanying editorial.

Saver said some doctors continue to lean on personal experience rather than solid data, despite evidence-based medicine being regarded as the gold standard. He noted that EBM can feel like it downplays individual clinical judgment. Still, Saver stressed that more research is needed, adding that the study underscores the importance of examining the evidence behind health professionals’ claims on social media.

How Health And Me Has Helped With Medical Facts

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