New COVID Variant EG.5 Now Makes Up Largest Proportion of New Infections Nationwide: What to Know

A fast-spreading new COVID-19 variant called EG.5 is now the dominant strain in the U.S.

Data gathered by the Centers for Disease Control and Prevention (CDC) between July 23 to Aug. 5 showed that 17.3% of new COVID-19 cases nationwide were caused by EG.5 — also known as “Eris” — up from 7.5% the first week of July.

EG.5 also is on the rise in several other countries globally, including China, South Korea and Canada. On Wednesday, the World Health Organization classified it as a “variant of interest.”

EG.5 —which was first detected in the U.S. in the spring — is closely related to the XBB variants that have been circulating for the past six months. It notably contains a particular mutation in its spike protein known to evade some of the immunity a person gets after an infection or vaccination.

Last month, EG.5 quickly surpassed the prevailing Omicron XBB variants which had accounted for the largest share of U.S. cases, indicating it’s likely more transmissible. According to CDC data, in April 29, the XXB 1.5 (Omicron) variant caused 73.5% of COVID-19 cases in the U.S. though the latest data shows the same variant only accounts for 10.3% of cases.

However, health experts say EG.5 does not cause more severe illness and is associated with similar symptoms as the XBB variants. Those symptoms include a cough, sore throat, runny nose, fatigue, headache, muscle aches and an altered sense of smell.

“Omicron is out there making minor variations. It’s having children, progeny, but they’re all closely related to omicron,” Dr. William Schaffner, a professor of preventive medicine and infectious diseases at Vanderbilt University Medical Center, told ABC News. “They are contagious, but they are not more serious, so that’s excellent.”

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Andrew Pekosz, a professor of molecular microbiology and immunology at Johns Hopkins University, said waning population immunity is likely contributing to the rapid spread of EG.5.

“It’s been quite a long time since boosters were provided for COVID, and those boosters did have a relatively low uptake rate in the population. That, combined with the fact that the XBB variants look different to your immune system from the [variants used in] previous COVID vaccines, means there’s probably a lot of susceptible individuals in the population,” he explained in an interview published by the Bloomberg School of Public Health.

Pekosz said the new variant shouldn’t be of high concern to the generation population. However, he urged those people who are particularly susceptible to severe COVID-19 — including the elderly and those with certain medical conditions — to be more cautious and make sure they have access to testing and antivirals. Additionally, he advised those individuals to consider wearing a mask and practicing social distancing.

Pekosz also noted that the new COVID vaccine, set to be rolled out in the fall, is based on the XBB variants, and therefore should provide good immunity for EG.5. “There should be a nice match between that vaccine and the EG.5 variant, as well as the other XBB variants that are circulating right now,” he explained.