Since its emergence in late 2021, the Omicron variant and its ever-changing sublineages—like XBB, JN.1, XEC, and NB.1.8.1—have continued to reshape the COVID‑19 landscape. As of mid‑June 2025, here’s the current state of play and what you need to know.
1. A Global Resurgence, but Mostly Mild
According to the World Health Organization (WHO), global SARS‑CoV‑2 activity has steadily climbed since February 2025. The test positivity rate among sentinel sites has risen to about 11%, a level last seen in July 2024 who.int. This uptick is driven largely by regions in the Eastern Mediterranean, South‑East Asia, and the Western Pacific. In contrast, Europe and the Americas remain stable, with lower positivity (2–3%) and no marked increase in hospitalizations who.int.
The picture is largely positive: hospitalization and ICU numbers remain flat, and mortality rates are low compared to earlier pandemic stages . A surge in mild cases has been observed, resembling seasonal respiratory infections during monsoon transitions timesofindia.indiatimes.com+15thelancet.com+15timesofindia.indiatimes.com+15.
2. Variant Watch: What’s Dominating the Curve?
COVID‑19 continues to evolve, and multiple Omicron-derived sublineages are in play:
🔬 NB.1.8.1 (“Nimbus”)
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Classified by WHO as a Variant Under Monitoring (VUM), NB.1.8.1 first appeared in January 2025 economictimes.indiatimes.com+9data.who.int+9who.int+9.
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As of late May, it accounts for ~10.7% of global sequences who.int.
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Characteristic spike mutations include T22N, F59S, G184S, A435S, V445H, and T478I arxiv.org+15data.who.int+15who.int+15.
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Though detected in Asia, North America, and Europe, it's notably increasing in India, where India's Ministry of Health reported a five-fold rise in cases, but without heightened illness severity abcnews.go.com+11sanews.gov.za+11indiatimes.com+11.
🧬 JN.1 and XEC
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JN.1, another Omicron descendant, has driven mild surges in Kolkata and Singapore, with symptoms mirroring earlier Omicron waves, including gastrointestinal upset in ~30% of cases who.int+7who.int+7timesofindia.indiatimes.com+7.
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XEC, a recombinant lineage from KS.1.1 and KP.3.3, was studied early in 2025 and showed increased transmissibility but no increase in severity who.int+3assure-test.com+3who.int+3.
XBB and Its Offshoots
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The XBB family, especially XBB.1.5, gained attention in the U.S. around late 2022–2023. It’s known for immune escape and greater cell‑binding efficiency medschool.duke.edu+7publichealth.jhu.edu+7ama-assn.org+7.
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However, XBB sublineages are not currently classified as “concern” by WHO; they are under regular review, but mild symptoms predominate thelancet.com+4cidrap.umn.edu+4data.who.int+4.
3. On-the-Ground Developments: Regional Snapshots
🇮🇳 India
India’s case count is rising again.
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A surge of 2,700+ active cases in May marks a five-fold increase, driven largely by NB.1.8.1 medtalks.in+11news24.com+11abcnews.go.com+11ama-assn.org+14who.int+14indiatimes.com+14.
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New hospital admissions are mostly mild; seven deaths were reported—all associated with underlying health problems timesofindia.indiatimes.com.
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Health authorities emphasize renewed mask usage, vaccination, and sound hygiene to mitigate the spread economictimes.indiatimes.com+2indiatimes.com+2indiatimes.com+2.
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In Indore, 41 positive cases were reported and local hospitals are maintaining vigilance and stocks, though the variant is mild timesofindia.indiatimes.com.
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Dr. Shashank Joshi affirmed that the current wave—an Omicron “great‑grandchild”—is mild and self-limiting in India, with no spike in hospitalizations timesofindia.indiatimes.com.
🇿🇦 South Africa
The emergence of NB.1.8.1 (called Nimbus) is being carefully monitored, but it has not triggered a surge similar to past waves citizen.co.za.
🇮🇳🇧🇩 West Bengal (India)
West Bengal’s chief minister declared COVID-19 endemic, with no new statewide measures planned. However, mask mandates may return if conditions change .
4. What’s the Clinical Reality?
Doctors describe a landscape of mild disease:
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Symptoms: fever, cough, sore throat, fatigue; gastrointestinal issues common in ~30% of cases .
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Hospital usage: Slightly increased isolation beds, but critical care and oxygen needs remain low .
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Risk groups: Elderly or immunocompromised individuals may still progress to severe illness swiftly .
5. Vaccines and Therapeutics: Keeping Up
✅ Updated Vaccines
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XBB.1.5-adapted mRNA vaccines (Pfizer/BioNTech, Moderna) are in use and show strong immune responses against multiple Omicron subvariants cdc.gov+10fda.gov+10tandfonline.com+10.
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These vaccines aim to reduce hospitalization and severe disease with broad cross-protection .
🔄 Boosters & Strategy
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Regular boosters remain the best defense for high-risk groups—elderly individuals and those with chronic conditions who.int+15who.int+15publichealth.jhu.edu+15.
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WHO recommends a risk-based, integrated approach: maintain surveillance, vaccination, hygiene, masks in indoor crowd settings who.int+1assure-test.com+1.
6. Testing & Surveillance: Early Detection Is Key
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Rapid antigen tests continue to be vital for early detection and isolation assure-test.com.
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WHO’s CoViNet and targeted genomic surveillance (e.g., traveler-based sequencing) offer timely detection of emerging variants who.int+1arxiv.org+1.
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Countries are enhancing genome sequencing via GISAID and eGISRS to track variant trends who.int+1ecdc.europa.eu+1.
7. What Lies Ahead?
😌 Expect Seasonal Fluctuations
The current increase mirrors seasonal patterns seen in 2024 and 2023. But COVID‑19 shows less predictable seasonality, so vigilance remains warranted .
🔍 New Variants Watch
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NB.1.8.1 (Nimbus) continues to climb but remains mild.
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Other VUMs—KP.3, LB.1, XEC—are being tracked carefully medtalks.in+13data.who.int+13who.int+13.
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Continued WHO evaluations will determine if any of these become Variants of Interest (VOI) or Concern (VOC).
🧬 Vaccine Evolution
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Future booster strategies will need to adapt as new spike mutations appear, with updated Omicron-centric formulations expected data.who.int+2who.int+2ecdc.europa.eu+2timesofindia.indiatimes.com+12medschool.duke.edu+12who.int+12.
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Duke University’s molecular studies emphasize how XBB lineages are evolving to optimize immune evasion and infectivity medschool.duke.edu+1thelancet.com+1.
8. Practical Tips for Individuals
Action | Recommendation |
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Stay updated | Follow local public health alerts. |
Vaccinate | Get recommended boosters, especially if high-risk. |
Test early | Use rapid tests at first sign of symptoms. |
Mask wisely | Indoor crowds? Mask up. |
Hygiene basics | Wash hands and cover coughs. |
Isolate/pause | If positive, stay home until recovered, especially to protect vulnerable contacts. |

Conclusion
Omicron’s evolution into XBB sublineages and the emergence of VUMs like NB.1.8.1 are ongoing. Thankfully, current evidence shows mainly mild disease, waning global severity, and health systems coping well.
Public health experts agree: we’re entering a new knowledge-based phase of the pandemic. Vaccines, surveillance, and community awareness form the pillars of defense—not fear.