Why has there been a global surge of new Covid variant NB.1.8.1?

Yahoo

5 hours ago

India is the latest country to report a surge in new Covid cases, as the latest variant NB.1.8.1 spreads across the globe.
Cases have now been reported in Asian countries such as Thailand, Indonesia and China, while the UKHSA recorded the first 13 cases in England last week.
However, the true numbers are unlikely to be known, given the significant decrease in the number of people testing compared to the figures seen during the global pandemic five years ago.
NB.1.8.1 stemmed from the Omicron variant and was first detected in January this year.
It has quickly spread across China and Hong Kong, and has now been recorded in several states across the United States and Australia.
By late April, NB.1.8.1 comprised about 10.7 per cent of submitted sequences globally, according to the World Health Organization (WHO). This rose from just 2.5 per cent one month before.
The WHO declared the NB.1.8.1 strain a 'variant under monitoring' on 23 May, which means scientists believe it could potentially affect the behaviour of the virus.
Lara Herrero, a virologist from Griffith University in Australia, suspects that NB.1.8.1 spreads more easily than other variants.
'Using lab-based models, researchers found NB.1.8.1 had the strongest binding affinity to the human ACE2 receptor of several variants tested, suggesting it may infect cells more efficiently than earlier strains,' Dr Herrero wrote last month in The Conversation.
Dr Chun Tang, GP at Pall Mall Medical, added: 'NB.1.8.1 isn't too different from the Omicron variant, but it does have some tweaks to its spike protein, which might make it spread a bit more easily or slip past some of our existing immunity.
'That said, early signs suggest it doesn't seem to cause more serious illness, but of course, we're still learning more about it.'
'Its spread has been identified in around 22 countries,' said Dr Naveed Asif, GP at The London General Practice.
'The WHO assesses the additional risk to the global public as currently low, and existing Covid-19 vaccines are considered effective in preventing severe disease.'
However, Nimbus does appear to be more transmissible than previous variants, with notable increases reported in India, Hong Kong, Singapore, and Thailand, notes Dr Asif.
Common symptoms of the NB.1.8.1 variant include a severe sore throat. fatigue, mild cough, fever, muscle aches and congestion.
It has also been reported that some patients have experienced gastrointestinal symptoms such as nausea and diarrhoea.
Healthcare experts have stressed, however, that there is no evidence that the new strain is more deadly or serious than previous variants, and that current Covid vaccines are expected to remain effective and protect anyone infected from severe illness.