New Variant of Coronavirus, EG.5, Becomes Dominant in the United States
A new variant of the coronavirus, known as EG.5, is now the leading strain in the United States, surpassing the previously dominant XBB.1.16 lineage. According to data from the US Centers for Disease Control and Prevention (CDC), EG.5 is responsible for approximately 17% of new COVID-19 cases in the country.
EG.5 is a spinoff of the XBB recombinant strain of the Omicron family, rather than a major evolutionary leap like the original Omicron strain. It has an additional mutation to its spike at position 465, which has been observed in other coronavirus variants in the past. Scientists are still uncertain about the specific effects this mutation enables the virus to have, but its prevalence in other variants suggests it may convey an evolutionary advantage over previous versions.
Furthermore, EG.5 has already given rise to another variant, EG.5.1, which has the addition of a second spike mutation. Both variants are spreading rapidly. Researchers, such as Dr. David Ho from Columbia University, have been testing the variants in their labs and have found that they are only slightly more resistant to neutralizing antibodies in infected and vaccinated individuals.
Clinically, EG.5 and its offshoot EG.5.1 do not appear to cause different or more severe symptoms compared to earlier variants. However, these variants have shown more immune escape, which explains their spread worldwide. They are particularly prevalent in Ireland, France, the UK, Japan, and China.
While EG.5 becomes the dominant strain in the US, there has been a recent increase in COVID-19 cases, emergency room visits, and hospitalizations. However, epidemiologists believe that human behavior, such as indoor activities due to record heat and increased travel, is the driving force behind this uptick. As schools reopen across the country, experts like Dr. Anne Hahn from Yale School of Public Health are cautiously optimistic that this wave of cases will not be as severe due to the population’s high immunity levels.
In preparation for the winter season, a fall booster targeting the XBB variant, including EG.5, is expected to provide strong protection. Vaccine manufacturers anticipate having the updated shots ready in a few weeks. However, CDC Director Dr. Mandy Cohen projects that the updated vaccine will be available in October, as it requires approval from the US Food and Drug Administration and a recommendation from the CDC. This delay has raised concerns among experts, especially for vulnerable populations with weakened immune systems.
Dr. Eric Topol, a cardiologist at the Scripps Translational Research Institute, expresses worries about other variants following EG.5. He suggests that variants with mutations allowing them to bind more tightly to cells could be even more infectious and consequential. He emphasizes the urgency of rolling out the updated vaccine promptly to prevent further spread.
The development of EG.5 as the dominant strain in the US highlights the need for continued vigilance and adherence to preventive measures. It also underscores the importance of expedited vaccine distribution to protect vulnerable populations and curb the spread of the virus.