Since May 2025, many countries have witnessed a significant surge in COVID-19 cases, largely driven by the emergence of new variants – particularly NB.1.8.1. China has reported a sharp spike in infections, while other regions including Singapore, Hong Kong, India, Vietnam, and the U.S. are also seeing alarming trends. As global health authorities monitor the situation closely, public concern is growing over the potential impact of these new COVID-19 strains. In this blog, we explore what COVID-19 variant we are on, meet the newest variant NB.1.8.1, its symptoms and how to stay safe in 2025.
As of May 2025, several COVID-19 variants continue to circulate globally, with newer sublineages of the Omicron JN.1 variant dominating case counts. In the United States, LP.8.1 has become the leading variant, making up approximately 70% of recent cases, as reported by the CDC. This variant has shown a high level of transmissibility but, like previous Omicron descendants, has not demonstrated increased severity in most patients. (USAtoday, CBS News, Hindustan Times).
In Singapore, LF.7 and NB.1.8 (both part of the JN.1 family) are currently the most prevalent strains, collectively accounting for more than two-thirds of locally sequenced cases. Countries such as India, Vietnam, Hong Kong, and Thailand are also reporting a rise in COVID-19 infections, largely driven by these newer subvariants. While hospital systems remain stable in most regions, health authorities continue to urge vigilance as these variants evolve. (Ministry of Health Singapore, updated 13 May 2025)
Identified first in China in early 2025, NB.1.8.1 is one of the most closely watched variants of the year. It has been classified as a “Variant Under Monitoring” by the World Health Organization (WHO) due to its rapid spread across Asia and its detection in multiple U.S. states through airport surveillance. Unlike its sibling variant NB.1.8, NB.1.8.1 is a more recent sublineage of Omicron JN.1, and it has been linked to a surge in case numbers in China, prompting global health authorities to increase genomic sequencing and surveillance.
In May 2025, NB.1.8.1 cases have expanded beyond Asia, appearing in the U.S. (California, New York, Virginia, Washington) and even Hawaii and Ohio, according to the CDC. Although there is no indication so far that NB.1.8.1 causes more severe illness, its swift geographic spread and potential for immune evasion make it important to monitor. Scientists are still studying whether this variant has any unique mutations that impact vaccine effectiveness or transmissibility differently than previous strains. (The Times of India, Kathmandu Post, CBS News, World Health Organization)
This variant, a descendant of the Omicron JN.1 lineage, presents symptoms that are largely similar to previous Omicron subvariants, though some individuals report variations in severity and duration.
Common Symptoms:
These symptoms are consistent with earlier Omicron strains and typically appear within 2–5 days after exposure. Most cases remain mild to moderate, especially among vaccinated individuals or those with prior infections.
Less Common or Additional Symptoms:
In rare instances, individuals have reported persistent low-grade hyperthermia, a condition where the body temperature remains elevated beyond normal due to failed thermoregulation, differing from typical fever.
Symptoms in Children:
Children infected with NB.1.8.1 often exhibit mild symptoms. However, it’s essential to monitor their condition closely, as their immune responses can differ from adults.
While NB.1.8.1 does not appear to cause more severe illness than previous variants, its higher transmissibility underscores the importance of vigilance. If you or someone you know experiences these symptoms, especially after potential exposure, it’s advisable to get tested and consult with a healthcare professional. Early detection and adherence to public health guidelines remain key in managing the spread of COVID-19 variants.
If you test positive for the NB.1.8.1 variant or exhibit symptoms consistent with COVID-19, it’s essential to take immediate steps to protect yourself and others. Here’s a comprehensive guide:
Begin by isolating yourself from others, even if symptoms are mild. The NB.1.8.1 variant is highly transmissible, and early isolation helps prevent further spread. Stay in a well-ventilated room and avoid sharing personal items.
Keep a close eye on your symptoms. Common signs include sore throat, fatigue, mild cough, fever, muscle aches, and congestion. Some individuals may experience persistent low-grade hyperthermia, headaches, nausea, loss of appetite, or gastrointestinal issues.
If symptoms worsen or you have underlying health conditions, consult a healthcare professional. While NB.1.8.1 doesn’t appear to cause more severe illness than previous variants, it’s crucial to stay informed and cautious.
Early consultation helps detect complications and prevent further spread to those around you. For convenience and peace of mind, you can access trusted medical advice from our MaNaDr online doctors via MaNaDr App.
Ensure you drink plenty of fluids and get adequate rest. Proper hydration and sleep support your immune system in fighting the virus.
Notify those you’ve been in close contact with recently so they can monitor their health and take necessary precautions. Early awareness can help curb the spread of the virus.
Adhere to local health authority recommendations regarding isolation duration and testing. Guidelines may vary based on your location and the severity of your symptoms.
Ensure you’re up to date with COVID-19 vaccinations and booster shots. Current vaccines are expected to remain effective against NB.1.8.1 in preventing symptomatic and severe disease.
By taking these steps, you not only safeguard your health but also contribute to the broader effort to control the spread of COVID-19 variants.
As COVID-19 continues to evolve, emerging variants like NB.1.8.1 raise questions about the effectiveness of existing vaccines. Here’s what current data indicates:
The World Health Organization (WHO) has designated NB.1.8.1 as a “Variant Under Monitoring,” noting that currently approved COVID-19 vaccines are expected to remain effective against this variant, particularly in preventing symptomatic and severe disease.
While NB.1.8.1 may have some ability to bypass immunity, vaccines still provide strong protection against severe illness, hospitalization, and death.
To enhance protection against circulating variants, the U.S. Food and Drug Administration (FDA) advisory committee has recommended updating COVID-19 vaccines to target newer strains, specifically those related to the JN.1 variant, such as LP.8.1. This recommendation aims to ensure broader coverage against variants like NB.1.8.1.
Vaccine manufacturers are responding accordingly. Moderna has submitted an application for an updated vaccine targeting the LP.8.1 subvariant, with plans for a mid-August release.
Health authorities emphasize the importance of staying current with COVID-19 vaccinations. Even as new variants emerge, existing vaccines continue to offer significant protection, and updated formulations are being developed to address evolving strains. Consult with healthcare providers to determine the best vaccination strategy based on individual health needs and local guidelines.
In summary, while NB.1.8.1 presents new challenges, current vaccines remain a critical tool in mitigating the impact of COVID-19. Ongoing surveillance and vaccine updates aim to maintain and enhance this protective effect against emerging variants.
With the rise of the NB.1.8.1 variant and other sub-lineages in May 2025, it’s more important than ever to adopt preventive measures to stay safe. While vaccines continue to provide protection, combining them with everyday habits can significantly reduce your risk of infection. Here’s how you can stay ahead of the virus:
Even if mask mandates have been relaxed in some places, wearing a well-fitted mask (such as N95 or surgical masks) in crowded or enclosed public spaces remains a highly effective barrier against respiratory droplets. This is especially important in high-risk areas such as hospitals, public transport, shopping malls, or events with large gatherings.
COVID-19 can spread via contaminated surfaces, so frequent handwashing with soap and water for at least 20 seconds is essential. If soap and water are not available, use a hand sanitizer that contains at least 60% alcohol. Also, avoid touching your face, especially your mouth, nose, and eyes when your hands are not clean.
Keeping a physical distance of at least 1 meter (3 feet) from others, especially in crowded settings, helps reduce your exposure risk. This remains particularly important in areas where COVID-19 cases are rising.
Boost your body’s natural defenses by eating a nutrient-rich diet. Include foods that are high in vitamins C and D, zinc, and antioxidants such as fruits, vegetables, lean proteins, and healthy fats. Fermented foods like yogurt and kimchi can also support gut and immune health. Stay well-hydrated and limit the intake of processed foods and sugars.
Engaging in regular physical activity not only improves your overall fitness but also strengthens your immune system. Aim for at least 30 minutes of moderate exercise five times a week, such as brisk walking, cycling, or home workouts. Exercise also helps manage stress and improves sleep – both of which are essential for immune health.
By making these prevention habits part of your daily life, you’re protecting yourself and your community. Prevention is still the strongest line of defense, especially as variants continue to evolve.
As new COVID-19 variants continue to emerge and spread across Asia and beyond, staying informed and proactive is key. Practicing good hygiene, maintaining a healthy lifestyle, and keeping your vaccinations up to date are essential steps in protecting yourself and those around you.
If you notice any health concerns or suspect symptoms of COVID-19, consult your healthcare provider as soon as possible. Download the MaNaDr App to book a trusted doctor from the comfort of your home and get the care you need, when you need it most.
