WHO Reports on New COVID-19 Variant NB.1.8.1: Risks and Vaccination Insights

The World Health Organization (WHO) has recently reported the emergence of a new COVID-19 variant, designated as NB.1.8.1, which is currently on the rise globally. According to the WHO, while this variant is becoming more prevalent compared to others, the overall risk to public health remains low. Routine clinical surveillance data has not indicated an increase in the severity of cases associated with NB.1.8.1 when compared to previously circulating variants.

In a logistic regression analysis, WHO researchers found that NB.1.8.1 exhibits a higher relative growth advantage than some co-circulating variants, such as LP.8.1.1. Yet, no evidence suggests that this variant is linked to increased hospital admissions, mortality rates, or any other significant clinical outcomes related to COVID-19, as noted in their report published on June 23, 2025.

Dr. Shirin Mazumder, an infectious diseases specialist based in Memphis, Tennessee, emphasized that the symptoms associated with the NB.1.8.1 variant are similar to those of earlier variants. These symptoms include fever, cough, runny nose, fatigue, body aches, nausea, vomiting, diarrhea, and notably, a sore throat reported by many patients. Dr. Mazumder mentioned that while sore throat is common among COVID-19 patients, the severity described by some as 'razor blade' remains to be distinctly linked to this new variant.

Despite the emergence of NB.1.8.1, Dr. Mazumder confirmed that current hospitalization rates for COVID-19 in the United States are stable, indicating no immediate cause for alarm regarding public health. The WHO's Technical Advisory Group on COVID-19 Vaccine Composition continues to assess the effectiveness of existing vaccines against emerging variants. Currently, the group recommends that monovalent JN.1 or KP.2 vaccines are appropriate for combating COVID-19, with monovalent LP.8.1 as an alternative.

To date, research has not demonstrated any negative impact of NB.1.8.1 on clinical outcomes or an increased resistance to antiviral treatments such as nirmatrelvir (Paxlovid). However, Dr. Mazumder cautioned that there are indications that this variant may exhibit immune escape characteristics, potentially diminishing the immunity conferred by both vaccination and previous infections. Nonetheless, she noted that since NB.1.8.1 is a descendant of the Omicron lineage, it is expected that existing vaccines may still provide some level of protection.

In conclusion, while the emergence of the NB.1.8.1 variant may raise concerns, current evidence suggests that it does not pose an increased risk compared to earlier variants. Ongoing monitoring and assessment by health authorities remain crucial as the situation evolves, and individuals are encouraged to keep up with vaccinations to maintain protection against COVID-19, including its variants.