Published: 8th June, 2025 in: Health Advice

NB.1.8.1 COVID Variant: Watch for These New Symptoms & How to Test Quickly

The NB.1.8.1 COVID variant, a newly monitored sub-variant of Omicron, is now spreading globally, including in the UK, Ireland, USA, Australia, and China. Early data suggests this strain may be more transmissible, though not necessarily more severe.

Read more: The Sun - Health warning as doctors warn of fast-spreading Covid strain | Axios - NB.1.8.1 cases detected in Washington

What’s different about NB.1.8.1?

Alongside typical COVID symptoms like fever, sore throat, and cough, emerging data highlights a rise in gastrointestinal symptoms:

• Nausea
• Vomiting
• Diarrhoea
• Heartburn
• Loss of appetite

Other reported symptoms still include fatigue, muscle aches, headaches, nasal congestion, and shortness of breath.

Source: The Sun - New COVID strain symptoms hit Irish holiday hotspots

Transmission & Current Status

• More transmissible: WHO classified NB.1.8.1 as a Variant Under Monitoring in May 2025.
• Prevalence has grown rapidly — now responsible for 10-11% of recent global sequenced cases.
• Detected in multiple travel-related cases worldwide, including UK, US, and Europe.

Should You Be Concerned?

Risk	Expert Guidance
Severity	No evidence of more severe illness compared to other Omicron variants.
Vaccine effectiveness	Current vaccines (including bivalent/XBB formulations) remain protective against severe illness.
Precautions	Continue good hygiene, consider masking in crowded places, and keep up to date with boosters.

Rapid COVID Testing Available

If you experience symptoms — particularly new stomach and gastrointestinal issues — prompt testing is advised to limit spread and confirm diagnosis.

Order your at-home test kit: COVID-19 Antigen Rapid Lateral Flow Test (Pack of 1)._