COVID-19 variant XBB.1.16 thread

[Michael Coston]

CDC Nowcast: XBB.1.5 Still Dominant - But XBB.1.16 Debuts in 2nd Place

XBB.1.1.6 Nowcast Estimates.



#17,408

The CDC's COVID Nowcast has been remarkably stable for the past couple of months, with XBB.1.5 making up roughly 90% of all COVID cases in the country, and very few signs of any competition by the other half dozen or so variants in the mix.

Omicron variants have a history of remaining dominant for only a few months, only to be replaced by something more `fit', and so we've been on the lookout for the next contender.​

While it had yet to be reported officially in the United States, yesterday in Preprint: Virological characteristics of the SARS-CoV-2 Omicron XBB.1.16 variant, we looked at a possible heir apparent which has been making inroads in India, and a few other countries around the world.

The authors suggested that XBB.1.16 might be the next variant to watch, writing:

Altogether, our data suggest that XBB.1.16 has a greater growth advantage in the human population compared to XBB.1 and XBB.1.5, while the ability of XBB.1.16 to exhibit profound immune evasion is comparable to XBB.1 and XBB.1.5. ​

Today's Nowcast from the CDC reports for the first time that XBB.1.16 is present in the United States - and has been for several weeks - and it appears to be making significant gains against XBB.1.5 in several areas of the country, most notably in the south (region 6 est. 21.3%).








All of these numbers are estimates. Revisions to previous week's numbers are common, and are more useful for spotting trends than nailing down exact percentages. The CDC has recently added the following caveat to their report.

Projections for an emerging lineage with a high growth rate may have a higher degree of uncertainty (wider predictive interval) when it is just beginning to spread and still has low weighted estimates. Projections may also be biased during times of delayed reporting (e.g., around holidays). CDC performs frequent evaluations of Nowcast to inform performance improvements. ​

Debuting impressively in 2nd place, XBB.1.16 could be on track to dethrone XBB.1.5 from the top spot in the weeks ahead.

Exactly what that means in terms of impact is difficult to say. Somewhat reassuringly, we've not seen any evidence that XBB.1.16 produces any greater severity of illness than earlier Omicron variants, but that is based on limited data.​

But another surge - even of a relatively mild variant - could produce significant morbidity and increased mortality, so we'll be watching its progress closely in the weeks ahead.

https://afludiary.blogspot.com/2023/04/cdc-nowcast-xbb15-still-dominant-but.html

 

[sharon sanders]

I coped Mike's blog post to this forum to start the XBB.1.16 variant thread

 

[Lance]

CIDRAP- XBB.1.6 picks up speed in US as WHO experts weigh COVID vaccine composition

https://www.cidrap.umn.edu/covid-19/xbb16-picks-speed-us-who-experts-weigh-covid-vaccine-composition

XBB.1.6 picks up speed in US as WHO experts weigh COVID vaccine composition

Lisa Schnirring

Today at 3:42 p.m.

COVID-19

​

The Omicron XBB.1.6 SARS-CoV-2 subvariant fueling India's surge is gaining traction in the United States, but so far the nation isn't seeing increases in cases, deaths, or hospitalizations, the US Centers for Disease Control and Prevention (CDC) said in its latest updates.

At the global level, overall cases and deaths continued to drop over the past 4 weeks, but some regions and individual countries are seeing notable case rises, the World Health Organization (WHO) said yesterday in its weekly update.

Also, the WHO vaccine advisory group that looked at the latest scientific evidence on vaccines and boosters said the bivalent (two-strain) versions appear to show broader immune response. The group said it will meet twice more this year to look at vaccine composition issues.

Newer variants cut into XBB.1.5 dominance

XBB.1.6 now makes up 7.2% of US samples, up from 3.9% the previous week, the CDC said in its latest variant projections. However, XBB.1.6 already makes up 21.3% of viruses in the south-central region of the country, which includes Arkansas, Louisiana, New Mexico, Oklahoma, and Texas.

Three other subvariants that still make up a relatively small proportion also gained ground: XBB.1.9.1, XBB.1.9.2, and XBB.1.5.1. Nationally, the proportion of XBB.1.9.1 is at 6.5%, up from 5.1% the previous week.

The CDC said the newer lineages could displace XBB.1.5. "At this time, the best ways to protect yourself and other from COVID-19 remain the same, regardless of which lineage causes infection."

In its weekly data summary, the CDC said the United States is averaging 14,491 new cases a day, down 17.3% from its previous 7-day average for new daily cases. About 190 Americans die from COVID-19 each day, down 25.5% from the last 7-day average for new daily deaths. New daily hospitalizations for COVID declined 14.6% from the previous week.

In other US developments:

• The CDC's Advisory Committee on Immunization Practices (ACIP) will meet on Apr 19, outside of its regularly scheduled meetings, to consider a potential recommendation for a second bivalent COVID booster, the agency confirmed to CBS News reporter Alexander Tin. Earlier this month, the Washington Post reported that the Food and Drug Administration (FDA) within the next few weeks was expected to authorize second boosters for those at highest risk, including those 65 or older and people who have weakened immune systems.
• The White House has asked federal agencies to revise their workplace policies to substantially increase on-site work at headquarters offices, according to Reuters, which saw the memo from the Office of Management and Budget.

Hot spots in India, Middle East

In its weekly update on the pandemic yesterday, the WHO said that, at the global level, cases and deaths continued their declines over the past 4 weeks, but levels for both are up in two of its six regions: Southeast Asia and the Eastern Mediterranean. It also said levels are rising in individual countries in other parts of the world.

The rise in Southeast Asia is led by India's steady surge in cases, fueled by the XBB.1.6 subvariant. Illness levels are also up in Indonesia. In the Eastern Mediterranean region, Iran, Qatar, and Saudi Arabia are among the countries with rising cases.

The WHO said XBB.1.5 is still dominant, but XBB.1.6 and XBB.1.9.1—recently added to its variants-under-monitoring list—are on the rise.

The latest weekly snapshot of COVID activity in Europe shows overall decreasing trends, but a mixed picture, the European Centre for Disease Prevention and Control (ECDC) said yesterday. For example, France has reported rising hospitalizations over the past 5 weeks in seniors, with Greece and Ireland also reporting rises in some of their metrics. Meanwhile, Latvia and a handful of countries in central and eastern Europe are reporting increased deaths.

WHO experts weigh booster composition

The WHO's technical advisory group on COVID vaccine composition met in the middle of March in Oman to review the performance of bivalent COVID vaccines and establish a timeline for a new recommendations for 2023.

In a statement today on the group's deliberations, the WHO said that, after reviewing the latest evidence, the group said both BA.1 and BA.4/5 booster versions provide a broader immune response than vaccine containing only the original virus. They added that the vaccines containing the BA.4/5 component prompt higher antibody titers to more recent Omicron lineages, as compared to boosters that have a BA.1 as the second component.

The group will meet twice more this year to review COVID vaccine composition, once in May and again about 6 months later.

 

[sharon sanders]

I copied the above post onto this thread.