Virus

One way to roughly evaluate the potential height of a wave is to look at the weekly increase in cases in the early days. It's not directly proportional but it will be related.

Omicron was a monster. pic.twitter.com/dFsINUYOQm

— JWeiland (@JPWeiland) December 31, 2022

Profound immune escape by XBB.1 even after 4 vaccine doses, including bivalent booster.

Study shows less effective cell entry for XBB.1.

But XBB.1.5 is a more advanced version, with F486P mutation instead of the older F486S on XBB.1.

XBB.1.5 binds better to ACE-2 receptor. https://t.co/z4yrBAzXXU pic.twitter.com/FDQgXc6fG1

— Rajeev Jayadevan (@RajeevJayadevan) January 6, 2023

New @CDCgov #SARSCoV2 variant report
Corrects/ lowers XBB.1.5 proportion of new cases from ~40% (last week) to 28% nationally now, leaving more runway before this variant achieves dominance cross country. No other variant showing growthhttps://t.co/jjl2AnOYb5 pic.twitter.com/SGHJmQ12NH

— Eric Topol (@EricTopol) January 6, 2023

7/ What do we conclude?

a) The variants are evolving at a massive rate.
b) The variants are evolving in partially immune populations to evade immunity and neutralisation by monoclonal antibodies.

— Dr David Berger, aBsuRdiSTe cROnickLeR (@YouAreLobbyLud) January 4, 2023

In case you hadn’t heard, the #Omicron (BA.5) Bivalent mRNA booster shots —available in USA since Sept 2022 —are effective against #XBB15. Don’t expect 100% efficacy but protection WILL KEEP IMPROVING for 3-6 months post-bivalent immunization #VaccinesWork https://t.co/ABaS2GmO8u

— Jeremy Kamil @macroliter@mastodon.social (@macroliter) January 6, 2023

The #Kraken subvariant: What to know about #omicron descendant #XBB15
It is in Australia
It is spreading rapidly across the US and UK.
It has shown to be vaccine resistant and able to evade immune defence #auspol https://t.co/YIZVvenLzz

— Au Purrr , #IStandWithUkraine (@ricklevy67) January 10, 2023

"Lab studies suggest that the bivalent vaccine is still effective in protecting against severe disease, though perhaps not as much against infection," Andy Pekosz(opens in new tab), a professor of Molecular Microbiology and Immunology at the Johns Hopkins Bloomberg School of Public Health, said in a statement(opens in new tab). "XBB.1.5 is derived from the omicron variant BA.2, and while the current bivalent vaccine was developed for the BA.5 variant, it has been shown to generate antibodies that recognize BA.2," he said.

The coronavirus is speaking. It’s saying it’s not done with us.
By Eric Topol, a professor of molecular medicine at Scripps Research
There’s no sugar-coating it: The world has let its guard down on covid-19. And the virus’s latest dominant form, XBB.1.5, makes clear that we’re doing so just as the virus finds new ways to hurt us.
The new dominant strain shows that the virus is always evolving to spread more quickly and infect us more efficiently. That should serve as a wake-up call for the country to re-invest in new vaccines, treatments and pandemic monitoring.
The XBB strain is the first fast-spreading recombinant variant — meaning it is a fusion of two omicron lineages. Its original version led to a wave of infections in Singapore. Then it added two critical mutations to become XBB.1.5, which was first detected in New York.
These two mutations maintain the high level of immune escape of XBB, while also adding more infectivity advantage, giving the virus better ability to attach itself to the receptors that get it into our cells. The variant identified has rapidly become dominant throughout the Northeast and is destined to do so across the country in the weeks ahead.
What’s more, it is picking up steam in many European and Asian countries. This tells us that XBB.1.5 is no slouch. It is outcompeting a soup of new omicron variants that have arisen in recent months.
While there is no indication that XBB.1.5 is more pathogenic or virulent, its ability to spread seems striking, given how quickly it rose to dominance in New York and contiguous states. XBB.1.5 now comprises well beyond 75 percent of infections in New York, Connecticut, New Jersey and Massachusetts. Hospitalizations have risen among seniors to levels only the first omicron wave surpassed.
Of course, it is hard to solely attribute this to XBB.1.5, given the population’s waning immunity, less frequent use of masks and other mitigation measures, and indoor gatherings during the holiday season. But the spike in hospitalizations in these states is significantly greater than in other regions in the country. And it is people 65 and older who, along with the immunocompromised, are the most vulnerable.
What can be done to defend against XBB.1.5? It is essential to get boosted, as new data from the Centers for Disease Control and Prevention show. Those who are 65 and older who received the bivalent vaccine are 80 percent less likely to be hospitalized. Furthermore, there is evidence that the bivalent vaccine — even though it targeted the earlier BA.5 variant — helps induce neutralizing antibodies and broaden immunity against XBB.1.5. Beyond boosters, the use of high-quality masks, rapid testing before gatherings, distancing, air ventilation and filtration will all help protect against infections.
Americans can take some comfort in the combined immunity from the country’s massive numbers of infections, reinfections, vaccinations and boosters. That should blunt the effect of XBB.1.5. Still, we have already seen the levels of covid hospitalizations in the United States reach their highest level in almost 11 months, and we’re not done with this wave yet.
The implications of XBB.1.5 are also much bigger than just this formidable variant. The virus is talking to us, and it is telling us it has many more ways to evolve. It is revealing that it not only can fake out or elude our immune response, but can also get better at penetrating our cells. What will happen next? Will we see a whole new family of variants arise that are distinct from the omicron family? It is entirely possible.
And we’re not ready for it. Genomic surveillance around the world has dropped 90 percent since early 2022, as reflected by sequenced samples deposited at the Global Initiative on Sharing Avian Influenza Data. That’s unacceptable. China is in the midst of a covid crisis with unmitigated spread, and it could become a breeding ground for functionally important variants in the months ahead.
Worse, there’s no coordinated, high-priority, accelerated or even funded efforts — either in the United States or globally — to develop the next-generation vaccines that will block infections, such as universal, variant-proof vaccines with extended duration of protection. Nor do we have drugs to replace the monoclonal antibodies that no longer work or for Paxlovid, in case resistance emerges to that treatment.
We’ve moved from complacency to frank capitulation at just the wrong time. If XBB.1.5 is telling us one thing, it’s that we can’t be oblivious. We’re all tired, but we’re up against a force that isn’t. We have the intelligence, resourcefulness and ingenuity to finally get ahead of the virus, but politics and unwillingness to invest are holding us back. We cannot afford that gridlock.