Take a look at the essential events, concepts, terms, quotes, or phenomena every day and brush up your knowledge. Here’s your UPSC Current Affairs knowledge nugget for today on the new Covid variant PJ.2.1.A new SARS-CoV-2 variant, PJ.2.1, is drawing attention after being identified in Canada in May 2026 and subsequently detected in several countries, including the US, Singapore, Australia, France and Spain. Let’s know about this new Covid variant and other viral diseases that have been in the news.1. PJ.2.1, described in the Journal of Infection as a “novel saltation variant”, originated from MC.10.1.7, a descendant of the JN.1 lineage that circulated until May 2025, and was first detected in Ontario, Canada, on May 2, 2026, before cases were reported in other Canadian provinces.2. By June 30, the variant had also been identified in the US, beginning with a case in New York City. Subsequent detections were reported across several states, including California, Florida, Arizona and New Jersey.3. Based on wastewater surveillance, the researchers described PJ.2.1 as the “fastest-growing variant in the USA” at the time of the study. Beyond North America, sequences of the variant were reported in Singapore, Australia, New Zealand, Israel, France and Spain, suggesting that its spread is not confined to one region.4. PJ.2.1 is a saltation variant because it has many new mutations in the spike protein, which help it attach better to human cells and escape some old immunity.5. Its symptoms look just like a common cold or seasonal flu. Patients report fever, severe sore throat, runny or blocked nose, cough, headache, muscle ache and fatigue.Story continues below this ad6. Notably, there is no evidence that PJ.2.1 causes more severe disease or hospitalisation than earlier variants.What is Covid-19, and how does PJ.2.1 differ from earlier variants?7. Coronavirus disease (COVID-19) is an infectious disease caused by the SARS-CoV-2 virus. The most common symptoms of COVID-19 are fever, chills, and sore throat. The key difference between PJ.2.1 and Covid-19 variant lies in its genetic changes and interaction with human cells.8. The PJ.2.1 has a highly mutated spike protein and showed increased ability to interact with the ACE2 receptor, which the virus uses to enter human cells. Laboratory experiments also indicated greater cell-entry efficiency in certain cell lines.Other viral diseases1. Hantavirus: Named after the Hantan River in South Korea, hantavirus is a family of rodent-borne viruses that can cause serious illness and death in humans. However, the virus-carrying rats and other rodents do not fall ill to the virus.Story continues below this ad— Human infection primarily occurs through contact with the urine, faeces, or saliva of infected rodents or by touching contaminated surfaces. It is also possible to get the infection by breathing air that contains viral particles stirred up from these droppings, according to the US Centers for Disease Control and Prevention (CDC).ALSO READ | Top 20 UPSC Current Affairs Pointers of the past week | November 2 to 8, 2026— Notably, Hantavirus rarely transmits from one person to another, which means in most cases infected persons have individually come in contact with the urine, faeces, or saliva of infected rodents or by touching contaminated surfaces.2. Mpox: Previously known as monkeypox, Mpox is a self-limiting viral infection caused by mpox virus (MPXV). The most common symptoms of mpox include fever, headache, muscle aches, back pain, low energy, and swollen lymph nodes, along with pox-like rashes that last for two to three weeks. It is a self-limiting disease but can lead to death, especially among children and those with weak immune systems.— According to WHO, there are two broad clades of the Mpox virus: clade I and II. Clade I leads to more severe disease and death than clade II in the populations where it is endemic.Story continues below this ad— Mpox spreads from person to person mainly through close contact with someone who has mpox. Someone who comes into physical contact with an animal that carries the virus, such as some species of monkeys or a terrestrial rodent (such as the tree squirrel) may also develop mpox.3. Nipah virus: Nipah is a viral infection that mainly affects animals such as bats, pigs, dogs, and horses. Being zoonotic, it can jump to humans who come in contact with the infected animals and cause serious disease. — Nipah can spread to humans after close contact with infected animals or secretions containing the virus on fruit trees, fruits, date palm sap, juice or toddy. It can spread from human to human through close contact at home or in hospitals. It can spread from handling dead bodies of those with Nipah.— According to the US Centers for Disease Control and Prevention (CDC), its symptoms are fever, headache, cough, sore throat, difficulty in breathing, and vomiting. In severe cases, disorientation, drowsiness, seizures, encephalitis (swelling of the brain) can occur, progressing to coma and death. Notably, there are no antivirals and there is only symptomatic management.Story continues below this ad4. Zika: A mosquito-borne disease—Zika virus— mainly occurs in tropical and subtropical areas of Africa, the Americas, Southern Asia, and the Western Pacific.— It is infected by Aedes species mosquitoes, which are the same ones that spread dengue and chikungunya viruses, and bite during the first week of infection. It is primarily transmitted through mosquito bites, sex, and breastfeeding.5. Ebola: It is a virus that can spread quickly and can be fatal in up to 90% of cases. Symptoms include fever, vomiting, diarrhoea, muscle pain and at times internal and external bleeding and can start to occur between two and 21 days from infection, according to WHO.— The virus is most often spread by close contact with bodily fluids of people exhibiting symptoms and with contaminated objects such as sheets.Story continues below this adBEYOND THE NUGGET: What it means to be ‘Varients of Interest’ (VOI) and ‘Varients of Concerns’?1. ‘Varients of Interest’ are variants that are less effectively neutralised in labs by antibodies from infection or vaccination and have a potential to spread.2. A variant is designated as VOI by WHO if it shows a growth advantage over other circulating variants — meaning its proportion increases along with any increase in the total number of cases.3. A variant can be designated as VOI also if it is predicted to or known to change characteristics such as transmissibility, virulence, antibody evasion, or susceptibility to therapies and diagnostics.ALSO READ | Knowledge Nugget | Mahabharata to Arthashastra: 3 Indian manuscripts earn UNESCO recognition4. Once designated as VOI, the WHO monitors and tracks its global spread. The body also keeps assessing its public health risk and facilitate sharing of isolates. Member states have to report cases of VOI, monitor it, and conduct field investigations to study the potential impact of the variant.Story continues below this ad5. ‘Varients of Concerns’ are variants that result in increased transmission, severe disease leading to hospitalisation, and reduce effectiveness of vaccines.Post Read Questions(1) Consider the following statements: (UPSC CSE 2017)1. In tropical regions, Zika virus disease is transmitted by the same mosquito that transmits dengue.2. Sexual transmission of Zika virus disease is possible.Which of the statements given above is/are correct?(a) 1 only(b) 2 only(c) Both 1 and 2(d) Neither 1 nor 2(2) With reference to PJ.2.1, recently seen in the news. It is a:(a) SARS-CoV-2 variant(b) Highly pathogenic avian influenza (H5N1) strain(c) Mpox virus variant(d) Ebola virus strainAnswer Key1. (c) 2. (a)(Sources: Fast-spreading Covid variant PJ.2.1: What Indians need to know, WHO tags JN.1 strain as ‘variant of interest’ as Covid cases rise)Story continues below this adClick here to read the UPSC Essentials magazine for October 2026. Share your views and suggestions in the comment box or write to us at manas.srivastava@indianexpress.com.Subscribe to our UPSC newsletter. Stay updated with the latest UPSC articles by joining our Telegram channel – Indian Express UPSC Hub, and follow us on Instagram and X