The proportions of COVID-19 variants circulating nationwide have been relatively constant over the past five weeks, and health experts are uncertain as to why, ABC News reported Sept. 6.
After a quick rise to dominance in late June, the omicron subvariant BA.5 has plateaued over the past five weeks. The subvariant now accounts for 88.6 percent of all U.S. COVID-19 cases — the same proportion as a week prior, according to the CDC's latest estimates.
The strain's slowed growth rate provides little clarity on what may be in store for the U.S. this fall and winter, experts told ABC News.
"We still have open questions as to what this means for a fall surge and the opportunities for a new variant to displace it," said John Brownstein, PhD, an infectious disease epidemiologist and chief innovation officer at Boston Children's Hospital who is also an ABC News contributor.
Read the full report here.