Global rollbacks in testing and surveillance are making it difficult to track and identify new COVID-19 variants, officials with the World Health Organization said during a Sept. 22 media briefing.
"Our ability to track variants and subvariants around the world is diminishing because surveillance is declining," said Maria Van Kerkhove, PhD, the organization's COVID-19 technical lead. "That limits our ability to assess known variants and subvariants but also our ability to track and identify new ones."
Dr. Kerkhove said the WHO is currently tracking about 200 omicron sublineages, including BA.4.6, which now accounts for nearly 12 percent of U.S. cases, CDC variant proportion estimates show. She said the WHO is also keeping a close eye on BA.2.75, which has been detected in 37 states and the District of Columbia. The CDC recently began tracking the subvariant separately from BA.2 due to its positive growth rate. U.S. estimates show the subvariant currently accounts for 1.4 percent of cases.
While acknowledging the global progress that has been made in terms of reducing severe disease, Dr. Kerkhove said the virus is still circulating"at an incredibly intense level around the world," meaning the risk for potentially more dangerous variants to emerge remains.
"The more this virus circulates, the more opportunities it has to change, and this is something we are deeply concerned about," Dr. Kerkhove said.