23-06-2025
WHO Eyes Emerging COVID-19 Variant
A new variant of COVID-19 is on the rise globally, but the overall risk to the public remains low, according to a report from the World Health Organization (WHO).
Although the variant, NB.1.8.1, is increasing in proportion to other circulating variants, routine clinical surveillance data have not yielded any signs of increased severity associated with NB.1.8.1 compared to previously circulating variants, the WHO noted in the report.
In a logistic regression model comparing NB.1.8.1 to LP.8.1.1, NB.1.8.1 had an estimated higher relative growth advantage than co-circulating variants, according to the WHO. However, no evidence has appeared of increased COVID-19-related hospital admissions, deaths per hospitalizations, or all-cause mortality associated with the variant, the WHO report stated.
What to Look for
The symptoms of the NB.1.8.1 variant appear to be similar to prior variants of the virus, with such presenting symptoms as fever, headache, cough, runny nose, fatigue, body aches, nausea, vomiting, and diarrhea, said Shirin Mazumder, MD, an infectious diseases specialist in Memphis, Tennessee, in an interview.
'Sore throat is a common symptom of COVID-19 that occurs in upward of 70% of patients,' said Mazumder. Although some reports describe the sore throat associated with NB.1.8.1 as 'razor blade' in terms of severity, whether this symptom is distinctive of the new variant remains unclear, she noted.
As for any added severity, the NB.1.8.1 variant does not appear to cause more severe disease, Mazumder told Medscape Medical News. 'Although most people will recover after a COVID-19 infection, some will require hospital admission, and some will go on to develop long COVID, which we have seen with other variants,' she said. However, overall hospitalizations resulting from COVID-19 in the US are currently stable, she added.
Current Vaccine Still Recommended
The WHO's Technical Advisory Group on COVID-19 Vaccine Composition regularly assesses how well the available COVID-19 vaccines are performing against any variants. Currently, the group advises that monovalent JN.1 or KP.2 are appropriate COVID-19 vaccine antigens, with monovalent LP.8.1 as an alternative vaccine antigen.
To date, no studies have reported any impact of NB.1.8.1 on clinical outcomes, and no available evidence suggests resistance to nirmatrelvir (Paxlovid), according to the WHO. However, the effectiveness of the current COVID vaccine against this variant remains unclear at present, Mazumder told Medscape Medical News.
'There are some reports that the NB.1.8.1 variant exhibits signs of immune escape, which may lower the immunity provided by vaccines and prior infection,' she noted. Yet, the variant is descended from the omicron lineage for which the current vaccine is effective, and ideally it will retain some prevention activity against NB.1.8.1 as well, she said.
Mazumder had no financial conflicts to disclose.
