One thing we know for sure about SARS-CoV-2, the virus that causes COVID-19, is that it keeps changing. Since the start of the pandemic, we have seen several notable variants, including Alpha, Beta, Delta, and Omicron. New variants are a normal part of how viruses evolve, but keeping an eye on each emerging one is crucial to make sure people, both in the U.S. and around the world are prepared.

This is particularly important if a variant spreads faster, causes more severe illness, resists vaccines, or combines all these factors compared with the original virus.

The World Health Organization (WHO) uses letters from the Greek alphabet to name new coronavirus variants, beginning with Alpha, which first appeared in 2020. While COVID no longer sparks the same widespread fear, the virus continues to evolve.

Also Read: Popular Cough Syrup 'Coldrif' Banned For Kids In Several Indian States Due To Presence Of DEG; Why Is It Alarming?

Since 2020, countless variants have appeared, each carrying different levels of risk in different countries. Below, we take a chronological look at these variants, how dangerous they have been, and how they have been mutating across regions.

Covid Variant VS Covid Strain

Variants and strains are not the same. A variant occurs when the virus changes slightly (mutates) from the original version, often due to an error in its genetic code during replication. A variant is like a new version of the virus. A strain, however, is when the virus accumulates enough variants that it behaves differently, for example, becoming far more transmissible than the original. All strains are variants, but not every variant counts as a strain, as noted by NHS.

Alpha Variant (B.1.1.7)

By the end of 2020, the original L strain of COVID had undergone several mutations, including the S, V, and G strains. The first widely reported variant, B.1.1.7, known as Alpha, appeared in the U.K. in September 2020. Alpha triggered a global surge of infections before vaccines were available and was deadlier than the original virus. Common symptoms included loss of taste or smell, fever, dry cough, shortness of breath, headache, sore throat, congestion, nausea, vomiting, and diarrhea. Pfizer, Moderna, and Johnson & Johnson vaccines remained effective against Alpha.

Also Read: 33-Year-Old IT Professional Thought Work Caused Him Stress & Memory Lapse, Neurologist Revealed The Real Reason

Beta Variant (B.1.351)

Soon after Alpha, the Beta variant (B.1.351) emerged in South Africa and spread to other countries. According to CDC estimates, Beta was roughly 50% more transmissible than the original virus, though it only accounted for a small share of U.S. cases. Pfizer, Moderna, and J&J vaccines were still effective against Beta.

Gamma Variant (P.1)

The Gamma variant, P.1, appeared in Brazil in November 2020. It caused relatively few cases in the U.S., though CDC data in fall 2021 suggested it could sometimes cause breakthrough infections among fully vaccinated people. Gamma did not seem as contagious as Alpha or Delta.

Delta Variant (B.1.617.2)

Delta (B.1.617.2) surged in spring 2021, first dominating in India and spreading to over 130 countries, resulting in severe waves worldwide. It caused more serious illness and hospitalizations among the unvaccinated than previous variants.

Even as U.S. vaccination efforts were underway, Delta could evade some vaccine-induced immunity, leading to breakthrough infections, as per CDC. More than 70% of cases were reported in fully vaccinated individuals, prompting booster campaigns. Headache, sore throat, runny nose, and fever were the most common symptoms.

Delta Plus Variant

Delta AY.4.2, known as Delta Plus, was an offshoot of Delta rather than a standalone variant. It had two spike protein mutations that helped it infect cells more efficiently, making it about 10–20% more transmissible. Delta Plus caused a surge in the U.K. but did not take hold in the U.S.

Omicron And Its Subvariants

Omicron and its subvariants have been the dominant strains in the U.S. for nearly two years. The original Omicron (BA.1) no longer circulates widely, but its subvariants now drive most infections. Omicron was first detected in Botswana and South Africa in November 2021 and quickly spread globally. By December, it caused U.S. daily cases to exceed a million.

In 2022, several subvariants emerged, and in 2023, EG.5 (nicknamed “Eris”) became dominant, with BA.2.86 (“Pirola”) also under observation. Omicron subvariants spread very efficiently, partly due to over 30 mutations on the spike protein that increase their ability to infect human cells. Early data suggested the original Omicron caused less severe illness than earlier variants, but high case numbers could still strain hospitals.

Vaccines remain protective against severe disease, though breakthrough infections can occur. The CDC recommends staying up to date with boosters, including the updated 2023 fall shot designed to target EG.5 and BA.2.86.

Nimbus, Stratus And Frankenstein Variants

Nimbus and Stratus are informal names for Omicron subvariants being monitored in 2025. Nimbus (NB.1.8.1) appeared in China early in 2025. Highly transmissible, it spread across Asia, Europe, and the U.S., causing symptoms like a razor-like sore throat, fatigue, mild cough, and congestion.

Stratus (XFG) first appeared in Canada and became dominant in Europe and the U.K. It shows enhanced immune evasion and causes a hoarse or raspy voice in some patients.

Frankenstein Variant

“Frankenstein” is a nickname for hybrid variants formed when someone is infected with two COVID strains simultaneously. Stratus itself is a Frankenstein-type variant. These combination of viruses circulate like any other, but their mixed genetics can make them more transmissible or better at evading immune defenses.

How Many Covid Cases Are Being Reported Now Worldwide?

In India, the Ministry of Health and Family Welfare reports 30,440 cases from January to September 2025, though many go unreported due to self-treatment at home. Meanwhile, cases have been rising in the U.S. and U.K.

For the week ending September 27, 6.7% of Americans tested positive, slightly down from 7.9% the previous week. COVID accounted for 0.8% of U.S. deaths and 0.7% of ER visits during the same period.

SARS-CoV-2 continues to evolve. Healthy, vaccinated adults face lower risk of severe disease than during the Delta wave, but older adults and immunocompromised people should remain cautious. Public-health authorities in India and worldwide are actively monitoring variants and will highlight any that significantly change risk.

Ben Sasse, former Senator, on Tuesday shared that he has been diagnosed with pancreatic cancer. His diagnosis came at Stage 4.

Is Ben Sasse's Cancer Terminal?

The former two-term senator, 53, revealed this in a social media or X, message: “This is a hard note to write, but since many of you have already sensed something, I’ll get straight to it: Last week I was diagnosed with metastasized, stage-four pancreatic cancer, and I am going to die.”

Stage 4 cancers are terminal and his terminal diagnosis was "hard for someone wired to work and build, but harder still as a husband and a dad," he said.

Stage 4 cancers are terminal because the cancer has metastasized, which means it has spread from its original site or the primary tumor to distant organs and tissues. This makes it extremely difficult to cure with localized treatments like surgery or radiation.

However, the American Oncology Institute does note that stage 4 cancer always does not have to be terminal, especially with breakthrough treatment options like targeted therapy, immunotherapy, or precision medicine. There are now also advanced surgical techniques that use minimal invasion procedures.

Also Read: Ben Sasse Diagnosed With Stage 4 Pancreatic Cancer: What We Know About His Diagnosis

What Is The Chance Of Survival In Stage 4 Cancer?

According to the American Cancer Society, pancreatic cancer makes up about 3 percent of all cancers in the United States but accounts for roughly 8 percent of cancer-related deaths. Most patients are diagnosed at Stage 4, and the disease is widely regarded as largely incurable. Prostate cancer, by contrast, is the second most common cancer among men, and the majority of those diagnosed do not die from it. The five-year relative survival rate for non-metastasized prostate cancer is 97.9 percent, dropping to about 38 percent once it spreads. These figures highlight how early detection and effective treatment options make prostate cancer far more survivable than pancreatic cancer.

What Are The Treatment Options For Ben Sasse At Stage 4 Cancer?

While treatments including chemotherapy, radiation, and in rare situations surgery are available, stage-four pancreatic cancer is still considered largely incurable. The absence of effective early screening contributes to delayed diagnosis, and although a small number of patients, such as Ruth Bader Ginsburg, have lived longer following surgery, these cases are rare. Well-known individuals including Alex Trebek and Aretha Franklin also battled the disease, which remains one of the deadliest cancers in the United States.

Former senator and former University of Florida president Ben Sasse announced on Tuesday, Dec. 23, that he has been diagnosed with terminal stage 4 cancer, as per CNN News.

In the deeply personal message, the former Republican lawmaker from Nebraska described the diagnosis as a “death sentence,” while expressing appreciation for the steady support of his family and close friends.

“I’m fortunate to have incredible siblings and half a dozen friends who are truly like brothers to me. As one of them said, ‘Yes, you’re on the clock, but all of us are.’ Death is a cruel thief, and none of us escape it,” he added.

For many men trying to conceive, testosterone sounds like an obvious answer. It is often linked with strength, vitality, and male health, so the assumption is that higher levels must also support fertility. In reality, the opposite is often true. Medical experts caution that using testosterone, especially without supervision, can interfere with sperm production and quietly lower the chances of becoming a father.

To know more about the same, we got in touch with Dr. Ambavarapu Divya Reddy, Fertility Specialist, Nova IVF Fertility, LB Nagar, Hyderabad.

Can Increasing Testosterone Help You Conceive?

Dr. Ambavarapu Divya Reddy said, the short answer is no. Testosterone is a male sex hormone, but it does not support fertility in the way many people assume. In fact, taking testosterone can work directly against sperm production. For men who want children, using testosterone without expert guidance can quietly reduce fertility rather than improve it. Here is what doctors want patients to understand.

Why Testosterone Does Not Boost Fertility?

Testosterone is fundamentally opposed to male fertility when taken from outside the body. Using testosterone injections, gels, patches, or pellets suppresses the natural communication between the brain and the testicles that keeps sperm production going. Dr Reddy said, “When this system is switched off, sperm counts fall and in some cases drop to zero. Fertility declines instead of improving.”

This is why men who plan to have children should never begin testosterone therapy without speaking to a specialist.

How Does Sperm Production Work?

Sperm are produced in the testicles with the help of testosterone that is made inside the testicles themselves. This internal testosterone is tightly controlled by the brain through a hormone called luteinizing hormone, or LH.

Dr Reddy told us, when external testosterone is introduced into the body, the brain senses enough hormone is present and stops releasing LH. As a result, the testicles reduce their own testosterone production and sperm production slows or stops altogether.

In real-world practice, many men on testosterone therapy develop extremely low sperm counts or complete absence of sperm, known as azoospermia, often without any obvious symptoms. This is a well-recognised cause of male infertility and one that is largely preventable.

Low Testosterone And Fertility: What Doctors Do Instead

If a man truly has hypogonadism, meaning he has symptoms along with low testosterone levels on blood tests, treatment is still possible but must be handled carefully. Current guidelines from the AUA, ASRM, and endocrine societies strongly advise against starting standard testosterone replacement in men who want children in the near future.

Instead, specialists use treatments that can raise testosterone levels while allowing sperm production to continue. These include clomiphene, human chorionic gonadotropin or hCG, and other targeted therapies that stimulate the testicles rather than shutting them down. Updated guidance for 2024 and 2025 stresses identifying the cause of low testosterone and choosing options that protect fertility.

If you think you have low testosterone but want children

a) Do not self-prescribe testosterone.

b) Consult a reproductive urologist or endocrinologist.

c) Ask about fertility-preserving treatments such as clomiphene or hCG and consider sperm banking if timing matters.

d) If you have already used testosterone, request a semen analysis and hormone tests. Acting early can help guide recovery or fertility treatment.

Testosterone may seem like an easy solution, but external testosterone is a common and avoidable cause of male infertility. If having children is important to you, proper testing and specialist care matter. The treatment that relieves symptoms is not always the one that protects your ability to become a father.

A little-known virus is spreading steadily across different parts of the world, prompting growing concern among health experts. Often described as “untreatable” because there is no targeted antiviral medicine available, adenovirus is drawing attention due to how tough it is and how quickly it can pass from person to person.

Eric Sachinwalla, medical director of infection prevention and control at Jefferson Health, has cautioned that while most healthy individuals develop only mild illness, people in high-risk groups may face more serious health problems. This raises an important question: just how contagious is this mystery illness that is spreading?

Adenovirus: How Contagious Is It?

Yes, adenovirus is highly contagious and spreads with ease in several ways. It can pass through respiratory droplets released during coughing or sneezing, close physical contact such as hugging or shaking hands, and contact with contaminated surfaces like toys and towels.

It can also spread through fecal matter, particularly during diaper changes, and in some cases through water. According to the CDC, the virus spreads quickly in crowded settings such as schools and daycare centres and can survive for long periods on surfaces, making good hygiene especially important for young children and people with weakened immune systems.

Who Do Adenoviruses Affect Most?

Adenoviruses can infect people of all age groups, but they are most commonly seen in children under the age of five. In babies and young children, the virus often spreads in daycare environments where close contact is common. Children are also more likely to put shared objects in their mouths and may not wash their hands as regularly.

Among adults, adenoviruses tend to spread in crowded living conditions. People staying in dormitories or military housing may have a higher risk of infection. The virus is also known to circulate in hospitals and nursing homes, as per CDC.

Those with weakened immune systems are more likely to become seriously ill from an adenovirus infection. This includes people who have undergone organ or stem cell transplants, as well as those living with cancer or HIV/AIDS. Individuals with existing heart or lung conditions may also face a higher risk of severe illness.

Adenovirus: What Are The Symptoms Of An Adenovirus Infection?

The symptoms of an adenovirus infection depend on the part of the body affected. Most commonly, the virus targets the respiratory system. When it infects the airways, it can cause symptoms similar to a cold or the flu. These may include:

• Cough.
• Fever.
• Runny nose.
• Sore throat (pharyngitis).
• Pink eye (conjunctivitis).
• Ear infection (otitis media).
• Swollen lymph nodes.
• Chest cold (bronchitis).
• Pneumonia.

Adenoviruses can also infect the digestive system. When this happens, diarrhea may occur, along with gastroenteritis. Gastroenteritis is inflammation of the stomach or intestines and can lead to stomach pain, diarrhea, nausea, and vomiting.

In rarer cases, adenoviruses can affect the bladder or the nervous system. Infection of the bladder may result in urinary tract infections. When the nervous system is involved, it can lead to serious conditions affecting the brain, including encephalitis and meningitis.