Experts are raising alarms about a dangerous new Covid variant known as NB.1.8.1 or 'Nimbus'. This variant, which first emerged in China, has been associated with a notable increase in Covid cases and emergency room visits. Since its initial detection in the United States in late March, data indicates that Nimbus now accounts for over one-third of all Covid cases nationwide, making it the second-most prevalent variant in the country.
Early research suggests that Nimbus can attach to human cells more effectively than its predecessors, which makes it the most infectious strain identified to date. Patients infected with Covid have begun to report a new and distressing symptom referred to as ‘razor blade throat’—a sharp pain that seems to be more intense than what has been experienced with earlier variants. While the CDC has not yet released official data tracking this new variant, the Global Initiative on Sharing All Influenza Data (GISAID) reported on June 11 that Nimbus has been detected in 13 states, including California, New York, New Jersey, and Hawaii.
The Covid-19 virus is known for its constant mutations, and laboratory tests have revealed new changes to the spike protein of the Nimbus strain, which may enhance its infectiousness compared to currently circulating variants. According to data from the World Health Organization (WHO), Nimbus constitutes over half of the variants circulating globally. The variant was named 'Nimbus' by Canadian evolutionary biologist T Ryan Gregory, who has been influential in coining names for various strains.
In laboratory tests, researchers found that the latest Omicron offshoot strain demonstrates a significantly stronger capability to attach to the receptors that allow the virus to invade human cells. Dr. Lara Herrero, a virologist at Griffith University in Australia, noted that this suggests Nimbus may infect cells more efficiently than earlier strains. A preprint study also indicated that antibodies from both vaccines and past infections were approximately half as effective at blocking Nimbus compared to the currently dominant LP.8.1.1 strain in the U.S.
Many Covid patients have taken to social media to share their experiences with the severe sore throat associated with Nimbus. Reports indicate that this symptom has led to sleepless nights, with some describing the pain as so severe that they were ‘whimpering’ and ‘clawing’ at their throats. Many have found it nearly impossible to swallow without intense pain and were unable to speak for extended periods.
In Asia, Nimbus has already caused significant outbreaks, resulting in over 1,000 infections in India and approximately 14,000 in Hong Kong and Singapore. The WHO has categorized Nimbus as a ‘variant under monitoring’. Despite its spread to 22 countries, the WHO maintains that it currently poses a relatively low global public health threat due to widespread vaccine coverage and population immunity. The organization stated that currently approved Covid-19 vaccines are expected to remain effective against Nimbus, particularly in preventing symptomatic and severe disease.
Experts are predicting an increase in Covid cases this summer, a trend that has been observed every summer since 2020. As immunity from previous vaccinations and infections wanes by mid- to late-summer, combined with the fact that people typically spend more time indoors in air-conditioned environments, a rise in transmissible variants is anticipated. Dr. Albert Ko, an epidemiologist at Yale School of Public Health, indicated that an uptick in cases is expected, although he believes it will be smaller than the surges seen during winter months.
In response to the emergence of Nimbus, vaccine manufacturers are working on updating their formulas. Moderna recently announced that its updated mNEXSPIKE shot is set to be available by fall. This updated vaccine will have a lower dosage specifically designed for adults aged 65 and older, as well as individuals aged 12 to 64 who have underlying health conditions that increase their risk for severe Covid, including cancer, diabetes, HIV, obesity, or pregnancy. Additionally, the FDA has recently restricted the availability of Covid vaccines to these specific populations.
