What is the JN.1 variant of coronavirus that is sparking concerns about the return of covid-19, and is it dangerous? All you need to know

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A new variant of coronavirus has insidiously spread throughout Asia, including China, Singapore, Hong Kong, Thailand and India. 257 active infections were reported nationwide, indicating a small rise in cases in India, according to data from the Ministry of Health and Family Welfare (MoHFW). Infections in Singapore rose from 11,100 cases in the final week of April to over 14,000 cases in early May 2025.

New Omicron sub-variants, especially JN.1 and its descendants like LF.7 and NB.1.8, are the primary cause of the surge. With 69 cases since 12th May, Kerala has seen the highest number of new infections followed by Tamil Nadu with 34 and Maharashtra with 44. Karnataka recorded 8, Gujarat 6, Delhi 3 while Haryana, Rajasthan and Sikkim each witnessed one new case.

Two recent Covid-19-related deaths were reported at King Edward Memorial (KEM) Hospital in Mumbai. Both patients had severe medical issues, according to the doctors. One was a 54-year-old cancer patient and the other was a 14-year-old with nephrotic syndrome-related renal failure. Health professionals have frequently expressed concern that India might observe a rise in cases as a result of the population’s declining immunity.

The LF.7 and NB.1.8 variants, which are sub-lineages of the larger JN.1 variant, have been connected to the raise in cases in Singapore and Hong Kong. However, the existence and dissemination of JN.1 strains in India have not yet been verified by health authorities.

“A new wave of Covid-19, circulating in southeast Asia with its epicentre in Singapore, has been in the news for the last few days. Along with Singapore, Hong Kong and Bangkok are also reporting a sudden rise in cases Such a peak can be due to the waning population immunity, non-compliance with the annual vaccination protocol, and the emergence of new sub-variants,” stated Dr Subhashree Samantaray, associate consultant, infectious diseases, Manipal Hospital Bhubaneswar, reported Hindustan Times.

What is JN.1

The JN.1 strain is closely related to BA.2.86 (commonly known as “Pirola”), a lineage of the Omicron variant, according to Yale Medicine. “A difference between BA.2.86 and JN.1 is that the latter has one mutation in its spike protein, a single change that may or may not alter any of the traits that characterise the virus, although preliminary research shows that it may provide extra immune evasion,” revealed Yale Medicine.

“It has acquired the ability to transmit efficiently through an additional one or two mutations,” as per Johns Hopkins Medicine. The World Health Organization (WHO) designated JN.1 as a Variant of Interest in December 2023 after it was first discovered in August 2023. It possesses roughly 30 mutations that enable it to evade our immune systems. This variat could spread more effectively than its predecessors because it has even evolved with more mutations.

However, among the SARS-CoV-2 variants that were in circulation in 2023, the BA.2.86 coronavirus variant never emerged as dominant. Now, JN.1 altered to propagate more effectively despite its parent’s immune evasion. Doctors maintain it’s not necessarily more severe, despite being genetically intelligent. However, it is challenging because it can avoid immunity.

 Dr Sandeep Budhiraja, Group Medical Director, Max Healthcare & Senior Director, Institute of Internal Medicine informed, “The current JN.1 variant is not more severe than past variants but is more transmissible. That’s why it’s causing concern across Asia.”

JN.1 in India and its symptoms

The current wave is unusual, especially during the summer when respiratory diseases typically decline, according to Dr Diksha Goyal, Senior Consultant, Internal Medicine, Marengo Asia Hospitals, Gurugram. The increase is probably due to declining immunity because most people have not had booster injections recently and were vaccinated a long time ago.

“This unusual summer wave is being linked to waning immunity, since many people haven’t received booster doses in over a year,” she stated. “Covid-19 hasn’t disappeared. It’s become endemic and will likely cause periodic spikes. What’s important is to monitor these carefully, especially through genomic surveillance,” Dr Sandeep Budhiraja disclosed.

The majority of JN.1 cases are minor and its symptoms are akin to those of earlier Covid-19 variants. Common signs and symptoms include: a sore throat, blocked or runny nose, dry cough, fever and chills, headache, muscle aches, fatigue or exhaustion, nausea or diarrhoea and loss of smell or taste (less common now).

According to Johns Hopkins, there are indications that JN.1 might be causing more diarrhea than earlier strains. “There’s nothing unusual about the symptoms. It behaves like earlier Omicron strains. But people with weaker immune systems may experience more fatigue,” Dr Sandeep Budhiraja outlined.

The majority of cases, according to doctors, are moderate and manageable at home. Nonetheless, high-risk groups, including the elderly, those with heart disease or diabetes and individuals using immunosuppressants should exercise special caution. “Most patients recover well, but we are seeing more moderate cases in high-risk groups,” Dr Diksha Goyal expressed.

How does JN.1 spread, its testing and precautions

Doctors stated that JN.1 spreads more effectively than its parent strains. Its modifications let it to evade some immune reactions and adhere to human cells more readily. The virus spreads similarly to previous Covid variations:

  • Droplets in the air from sneezing, coughing or talking.
  • Close proximity in congested or inadequately ventilated indoor environments.
  • Surface contamination (less frequent but still possible).

Dr Niranjan Patil, AVP at Metropolis Healthcare explained, “Standard real-time reverse transcription polymerase chain reaction (RT-PCR) tests are used for diagnosis. If a sample tests positive, it is then sent for genomic sequencing to identify the specific variant, such as JN.1.” The primary options for testing are:

  • RT-PCR (gold standard, accurate, but takes 24–48 hours) is one of the primary testing options.
  • Rapid Antigen Tests (RATs): less sensitive but faster
  • Multiplex PCR techniques that detect Covid and other respiratory viruses (e.g., BioFire, QIAstat)

Most labs charge between ₹500 and ₹800 for RT-PCR, according to government capping. The cost of multiplex tests is higher.

Dr Sandeep Budhiraja clarified, “Updated Covid-19 boosters provide significant protection against symptomatic JN.1 infections. They also significantly reduce the risk of severe disease and hospitalisation.” Although there are currently no vaccines that are specific to JN.1, health professionals strongly advise booster doses, particularly for individuals who belong to vulnerable populations.

Doctors advise wearing masks, particularly when in a high-risk group or in congested indoor environments. Precautionary actions consist of:

  • When in public indoor areas, wear a mask that fits properly.
  • Wash hands often.
  • Stay away from crowded areas if feeling sick.
  • Get dose of booster if haven’t already.
  • If tested positive, remain at home and isolate.

Physicians have advocated for improved reporting and increased international cooperation in order to stay ahead of future waves and prevent another worldwide epidemic. “Genomic surveillance helps identify emerging variants and track their spread. It is also crucial for updating treatment guidelines and vaccine strategies,” mentioned Dr Sandeep Budhiraja.

In India, the situation is still under control. On 19th May, the Director General of Health Services (DGHS) presided over a review meeting of specialists from the Indian Council of Medical Research (ICMR), the Emergency Medical Relief (EMR) division, the Disaster Management Cell, the National Center for Disease Control (NCDC) and central government hospitals.

The Health Ministry is nonetheless “vigilant and proactive in monitoring the situation closely,” according to a source who spoke to PTI and the right procedures are in place to protect public health.

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