A new omicron subvariant, HV.1, now accounts for more than a quarter of COVID-19 cases in the U.S., CDC data shows. Meanwhile, uptake of the new vaccine has been slow and new hospital admissions continue to decline.
Five COVID-19 updates to know this week:
HV.1: Experts believe the strain may be slightly better at evading prior immunity, which may explain its new dominance. There are no concerns surrounding changes in disease severity, and the new COVID-19 shots are expected to offer some level of protection against the strain, given it's a descendant of XBB.1.5, which the shots were initially designed to target.
Separately, the CDC is monitoring the spread of JN.1, a variant first detected in the U.S. in September. According to an Oct. 27 update, the strain is very similar to BA.2.86 and currently makes up less than 0.1% of cases. "With this limited information, it is too early to tell whether it will spread more widely," the agency said.
COVID-19 admissions have been declining in the U.S. for weeks. There were just over 16,100 new COVID-19 admissions for the week ending Oct. 21, marking a 0.2% decline from the week prior. Based on past trends, however, experts predict the nation may see another winter uptick in December or January — the same time of the year flu tends to peak.
Detecting COVID-19 gets murkier: A quarter of the nation's CDC-sponsored wastewater testing sites are shut down indefinitely as the agency looks to replace the firm it worked with on wastewater surveillance since 2020, sparking concerns among public health officials that there will be little insight into COVID-19's spread as colder months arrive. Read more here.
New vaccine rollout off to slow start: About 12 million Americans have received the new shots since mid-September, less than 4% of the U.S. There have been numerous reports about supply issues and difficulty accessing the new shots across the country. As of mid-October, many community health centers were still waiting on supplies to arrive. Pharmacies and nursing homes have also faced difficulties in stocking enough vaccines amid bumps in a new distribution model, which changed from federal entities to wholesalers and other private suppliers.
A new long COVID-19 theory: Remnants of the virus that causes COVID-19 may linger in the gut, ultimately causing a reduction in circulating levels of serotonin. According to new research from scientists at University of Pennsylvania in Philadelphia, this may explain a number of long COVID-19 symptoms, such as brain fog and memory problems. The findings are believed to connect many of the major hypotheses surrounding the causes of new or persistent symptoms, such as lingering virus components, inflammation and increased blood clotting.