In a technical briefing on SARS-CoV-2 variants today, the UK Health Security Agency (HSA) revealed that, of 34 confirmed involving the highly mutated BA.2.86 variant, 28 were from a single outbreak at a nursing home, an early sign that it can spread in close-contact settings.
In other developments, the United States' main COVID indicators showed a continued slow but steady rise in COVID activity, according to the latest updates from the Centers for Disease Control and Prevention (CDC).
High attack rate in nursing home outbreak
The HSA said BA.2.86 was detected at the nursing home in Norfolk after an unusually high number of people became ill during the last weeks of August. Positive samples were sent for genetic sequencing, which confirmed BA.2.86 in 28 of 43 samples. The attack rate was 86.6% among residents. Twelve staff members also tested positive.
Of 33 nursing home residents who tested positive, at least 29 had been vaccinated during the spring COVID booster campaign. All four of the residents who tested negative had received the shot in the spring.
Of the 34 cases reported so far in the United Kingdom, 5 people were hospitalized, and no deaths were reported.
Of the 6 cases that weren't part of the nursing home outbreak, 4 are in London, and the northwest and east regions each have 1 case. None of those 6 patients have epidemiologic links, and none of the 34 UK cases have a recent travel history.
Though it is too early to say how the new variant will behave in the wider UK population, the HSA said it may be sufficiently transmissible to have an impact in certain settings, including nursing homes.
It is clear that there is some degree of widespread community transmission, both in the UK and globally.
Renu Bindra, MD, the HSA's incident director, said its specialists are working with the Norfolk County Council on infection control and support following the nursing home outbreak. She said it's too soon to draw firm conclusions on what impact BA.2.86's mutations will have on transmissibility, severity, or immune escape.
She added, however, "It is clear that there is some degree of widespread community transmission, both in the UK and globally, and we are working to ascertain the full extent of this. In the meantime, it remains vital that all those eligible come forward to receive their autumn vaccine as soon as it is offered to them."
In another new development, the HSA said BA.2.86 was successfully cultured from the first UK case and is undergoing quality assessment before it is used to assess immune escape and diagnostic test performance.
Main US COVID markers continue upward creep
In its latest COVID data update, the CDC said its two main metrics show signs of further rise. Starting from a very low levels, hospitalizations for COVID have now been increasing for 9 weeks in a row.
US cases last week rose 15.7% compared to the previous week, with much of Florida in the medium ranges and parts of some southern states also listed as medium. A few parts of the country are in the high range, including counties in eastern Montana and some at the Alabama-Mississippi border.
Deaths rose 10.5% compared to the week before, but fatalities from COVID make up only 2.1% of the nation's deaths.
Other indicators showed slight declines. Emergency department visits for COVID dropped 1.5% compared to the previous week, with levels a bit higher in most southern states compared to the rest of the country. The test positive level declined 0.6% and is at 13.5% nationally. The CDC's maps show that test positivity is highest in Texas and surrounding states.