A new variant of COVID-19 dubbed EG.5 has become dominant in the U.S., according to projections made by the Centers for Disease Control and Prevention, although a shortage of data is hampering the agency’s efforts to surveil the illness.
The CDC said on Friday it was unable to publish its “Nowcast” projections for where EG.5 and other variants are circulating for every region, which it releases every two weeks, because it did not have enough sequences to update the estimates.
“Because Nowcast is modeled data, we need a certain number of sequences to accurately predict proportions in the present,” CDC representative Kathleen Conley said in a statement to CBS News.
“For some regions, we have limited numbers of sequences available, and therefore are not displaying nowcast estimates in those regions, though those regions are still being used in the aggregated national nowcast.”
It is estimated that EG.5, an omicron subvariant, accounted for 17.3% of COVID cases in the U.S. in the two-week period through Aug. 5. That was up from an estimated 11.9% in the previous period and more than any other variant.
But the data are based on sequencing from just three regions; Region 2, comprising New Jersey, New York, Puerto Rico and the U.S. Virgin Islands; Region 4, comprising Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina and Tennessee; and Region 9, comprising Arizona, California, Hawaii, Nevada, American Samoa, Commonwealth of the Northern Mariana Islands, Federated States of Micronesia, Guam, Marshall Islands and Republic of Palau.
The next most common variants are XBB.1.16, accounting for 15.6% of cases, and XBB.2.3, accounting for 11.2% of cases.
All are subvariants of XBB, which COVID vaccines in the fall will be designed to protect against.
The symptoms of EG.5, which Twitter users have nicknamed “Eris,” are similar to early variants, and it’s not deemed to be more virulent than early variants. It may be more infectious, however, as has been the pattern with new strains. Symptoms include a cough, fever, chills, shortness of breath, fatigue and a loss of taste or smell.
The World Health Organization said last week that EG.5 increased in prevalence globally to 11.6% in the week through July 30 from 62% four weeks earlier.
The variant is for now a variant under monitoring, or VUM, for the agency, which is a less serious designation than a variant of interest, or VOI, according to its weekly epidemiological update.
The WHO is monitoring two VOIs, XBB.1.5 and XBB.1.6.
It is tracking seven VUMs and their descendent lineages, namely BA.2.75, CH.1.1, XBB, XBB.1.9.1, XBB.1.9.2, XBB.2.3 and EG.5.
CDC data show that hospital admissions with COVID started to rise again in July after being flat or falling for several months. But the number of deaths continues to decline with 81.4% of the overall population in the U.S. having had at least one vaccine dose.