New Covid Variant Australia NB 1.8.1

NICOLE ENAD     30th May 2025

New Covid Variant Australia NB 1.8.1

FAST FACTS 

  • A new COVID variant, NB.1.8.1, has now been detected throughout Australia. The latest Victorian Covid surveillance report shows coronavirus notifications skyrocketed nearly 44 per cent across the state in the week leading up to May 16. 
  • Experts say NB.1.8.1 could play a role in a potential COVID winter surge, but symptoms are similar to other COVID infections however; 
  • The variant has been classified as a “variant under monitoring” by WHO, 

because of its growing global spread and some notable characteristics that could set it apart from earlier variants. 

  • The new variant may infect cells more efficiently than earlier strains, spread more easily and partially sidestep immunity from prior infections or vaccination. 


What’s Happening with COVID-19 Now? 

It’s been over five years since COVID-19 started spreading around the world. Even now, people are still catching the virus in waves. The Covid variants timeline so far: 


Infrographics by MedCart Australia. This graph is for general reference only, based on the author's research. It is not medical advice. For official guidance, please refer to health authorities like the WHO or the Australian Department of Health. 

Today, it's harder to know exactly how many people have COVID, because not everyone is getting tested or reporting it. But recent information shows that, in late May 2025, more people in Australia were starting to get sick again. 

A new version of the virus, called NB.1.8.1, has started spreading in Victoria, New South Wales (NSW), and Western Australia. Health experts are watching it closely, especially as winter begins (when more people get sick). 


What is NB.1.8.1? 

The new COVID variant Australia NB 1.8.1 is a new type of COVID-19 virus. Experts at the World Health Organization (WHO) say it comes from an earlier version called XDV.1.5.1, and the first case of it was found in January 2025. 

NB.1.8.1 is now one of six variants being closely watched by the WHO. It was added to the watch list on 23 May 2025 because of how it’s spreading and how it might affect people. 

This new COVID variant has several changes (called mutation) in its spike protein — the part that helps the virus enter our bodies. These changes make it different from other common variants like LP.8.1 and JN.1. 

Scientists are still studying NB.1.8.1 to learn: 

  • How fast it spreads 
  • If it makes people sicker 
  • If current vaccines still work well against it 

Because the new COVID variant Australia NB 1.8.1 is growing in places like Victoria, NSW, and Western Australia, health experts are keeping a close watch as winter begins. 


How Serious Is the New Covid Variant Australia NB 1.8.1? 

Health experts are currently monitoring the new Covid variant Australia NB 1.8.1. This variant was listed as a Variant Under Monitoring (VUM) by the World Health Organization (WHO) on 23 May 2025. Here’s what official sources are saying: 

 

What Do We Know So Far? 

  • The World Health Organization (WHO) has not found any current signs that NB.1.8.1 causes more severe illness than other COVID-19 variants, however, 
  • The new variant may infect cells more efficiently than earlier strains, spread more easily and partially sidestep immunity from prior infections or vaccination. 
  • The overall public health risk from NB.1.8.1 has been assessed by WHO as low, based on the evidence available as of May 2025. 
  • According to WHO, some areas (especially in the Western Pacific Region, like Australia) have reported more cases and hospital visits. 

 

Is NB.1.8.1 Spreading More? 

WHO reports that NB.1.8.1 is spreading faster than some other variants, including LP.8.1. 

Scientists have checked virus samples and found that NB.1.8.1 is growing in these areas. The latest Victorian Covid surveillance report shows coronavirus notifications skyrocketed nearly 44 per cent across the state in the week leading up to May 16. 

In Western Australia, tests of the water (called wastewater testing) show that NB.1.8.1 is now the most common version of COVID found in Perth. 

This new variant is also growing in other parts of the world. By the end of April 2025, it made up about 1 in 10 cases globally, which is a big jump from the month before. That’s why health groups in different countries are paying close attention. 

NB.1.8.1 is spreading a lot in Asia too – it was the main variant in Hong Kong and China by the end of April.  

What About Immunity? 

  • According to the WHO, lab tests using virus samples (pseudoviruses) show that NB.1.8.1 might partially escape immunity from vaccines or past infections. 
  • This immune escape was described as low risk, and confidence in the data remains low, meaning scientists need more information before making any firm conclusions. 


Does It Affect COVID-19 Treatments? 

  • WHO says there is no current evidence that NB.1.8.1 affects the effectiveness of treatments like Paxlovid (nirmatrelvir) or remdesivir. 
  • NB.1.8.1 does not appear to carry changes that would make it more resistant to these medicines compared to other variants. 

 
Summary of WHO's Current Assessment 

(As of May 2025) 



What does research say? 

A recent preprint study (not yet peer-reviewed) suggests NB.1.8.1 may spread more easily and might partly avoid protection from past COVID-19 infections or vaccines. However, these findings are early and have not yet been confirmed by global health authorities. 

What are the symptoms of the new COVID variant? 

The CDC has not outlined symptoms that are specific to the NB.1.8.1. variant. Reports have said that NB.1.8.1 symptoms appear similar to those of earlier COVID-19 variants. 

The CDC outlines the following as common COVID-19 symptoms: 

  • Fever or chills 
  • Cough 
  • Shortness of breath or difficulty breathing 
  • Sore throat 
  • Congestion or a runny nose 
  • New loss of taste or smell 
  • Fatigue 
  • Muscle or body aches 
  • Headache 
  • Nausea or vomiting 

 

Can current Covid tests detect NB.1.8.1? 

Yes, current COVID-19 tests can still detect the new NB.1.8.1 variant because it shares many similarities with earlier strains. The longer answer involves which part of the virus is actually being detected by the LFT and how SARS-CoV-2 mutates. 

To protect yourself, your family, and your community from COVID-19, it’s important to keep following safety measures: wear face masks in crowded or indoor places, wash your hands regularly, and test yourself if you feel any symptoms or have been around someone who is sick. Testing helps you catch infections early and stop the spread. 

MedCart is a trusted Australian provider of high-quality health and safety products, committed to helping you stay protected during the ongoing COVID-19 situation. 

We offer a wide range of trusted protective products to help you stay safe, including: 

For more detailed advice on COVID testing, what to do if you test positive, and ways to avoid infection, check out our blog: “Things to Know About COVID Tests and COVID in 2025.” 

Stay safe and keep your loved ones protected by using the right gear and testing regularly. Visit MedCart to find everything you need to guard against COVID-19 and its variants, including NB.1.8.1. 


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