This particular variant, known as EG.5 or Eris variant, was initially identified on February 17 of this year and was categorized as a variant under monitoring (VUM) on July 19. In its most recent risk assessment, the WHO has upgraded EG.5 and its sub-lineages to the status of a “variant of interest” (VOI).
These variants are broadly classified into three categories: (1) “variants of interest,” (2) “variants of concern,” and (3) “variants of high consequence.”
EG.5 is a descendant of the Omicron subvariant XBB.1.9.2. It bears an additional mutation in the spike protein—a key element used by the SARS-CoV-2 virus to enter and infect human cells—compared to its parent subvariant.
Within the lineage of EG.5, the subvariant EG.5.1 carries an additional spike mutation and constitutes 88 percent of the available sequences for EG.5 and its descendant lineages, as indicated by the WHO.
Up to August 7, a total of 7,354 sequences of EG.5 have been submitted to the Global Initiative on Sharing All Influenza Data (GISAID) from 51 countries. China has contributed the largest share of EG.5 sequences, accounting for 30.6 percent (2,247 sequences). Other nations with at least 100 sequences include the United States, the Republic of Korea, Japan, Canada, Australia, Singapore, the United Kingdom, France, Portugal, and Spain.
In India, there has been just one reported case of EG.5, originating from Pune in May of this year.
Globally, there has been a steady rise in the prevalence of EG.5. In the epidemiological week 29, EG.5 accounted for 17.4 percent of cases worldwide, according to the WHO.
Based on the current available evidence, the global-level public health risk attributed to EG.5 is deemed low, aligning with the risk associated with XBB.1.16 and other variants of interest that are currently circulating.
The current proliferation of Covid-19 variants like EG.5, also known as Eris, does not signify a significant shift, the director of the US Centers for Disease Control and Prevention said.
According to Director Dr. Mandy Cohen, “At present, the alterations observed in the viruses still render them susceptible to our vaccines, responsive to our treatments, and detectable by the tests.” She conveyed this during an interview on the “In the Bubble” podcast hosted by former Biden administration adviser Andy Slavitt. Dr Cohen further elaborated, “We are observing minor changes that fall within the realm of what could be considered subcategories of what we’ve encountered previously.”
The WHO’s risk evaluation report highlights that while EG.5 has exhibited increased prevalence, growth advantages, and characteristics of immune escape, there have been no reported changes in disease severity thus far.
While certain regions have observed concurrent increases in EG.5 prevalence and Covid-19 hospitalizations (albeit lower than previous waves), no definitive connections have been established between these hospitalizations and EG.5.
However, due to its growth advantages and immune escape traits, EG.5 could potentially lead to an uptick in case numbers and establish dominance in specific countries or even globally, according to the assessment by the global health organization.
The WHO, along with its Technical Advisory Group on SARS-CoV-2 Evolution (TAG-VE), continues to recommend that countries prioritize targeted measures to address uncertainties related to antibody escape and the severity of EG.5.
To this end, the WHO urges nations to share information regarding EG.5’s growth advantages and provide sequence data. Member countries are also encouraged to conduct neutralization assays using representative human blood samples from affected communities, as well as live virus isolates of EG.5.
Furthermore, the WHO and its Technical Advisory Group on Covid-19 Vaccine Composition (TAG-CO-VAC) are regularly evaluating the impact of variants on the effectiveness of Covid-19 vaccines. These assessments inform decisions about potential updates to vaccine compositions.
Here is an FAQ on Covid variants:
What is the difference between a variant of interest and a variant of concern?
A variant is designated as a “variant of interest” when it possesses mutations that are either suspected or confirmed to result in noteworthy alterations and is actively circulating on a significant scale (e.g., associated with multiple clusters of infections or prevalent across numerous countries). The World Health Organization (WHO) maintains ongoing surveillance of numerous variants of interest to ascertain their potential progression into “variants of concern.”
A “variant of interest” is elevated to the status of a “variant of concern” when it is documented to exhibit heightened transmissibility, induce more severe illness, evade the immune response of the body, modify clinical manifestations, or diminish the efficacy of established tools such as public health measures, diagnostics, treatments, and vaccines.
What is the difference between a ‘mutation’ and a ‘variant’?
Viruses undergo continual evolution and transformation. Whenever a virus replicates, it has the opportunity to undergo structural modifications. Each of these modifications is referred to as a “mutation.” A virus that possesses one or multiple mutations is categorized as a “variant” of the original virus.
Certain mutations can result in alterations to significant attributes of the virus, encompassing traits that impact its capacity for transmission and/or its potential to induce heightened severity of disease and mortality.
(With inputs from agencies)